Yes I'll address the memory reservation functionality in a separate FLIP to cooperate with FLIP-49 (sorry for being late for the discussion).
Best Regards, Yu On Mon, 2 Sep 2019 at 11:14, Xintong Song <tonysong...@gmail.com> wrote: > Sorry for the late response. > > - Regarding the `TaskExecutorSpecifics` naming, let's discuss the detail in > PR. > - Regarding passing parameters into the `TaskExecutor`, +1 for using > dynamic configuration at the moment, given that there are more questions to > be discussed to have a general framework for overwriting configurations > with ENV variables. > - Regarding memory reservation, I double checked with Yu and he will take > care of it. > > Thank you~ > > Xintong Song > > > > On Thu, Aug 29, 2019 at 7:35 PM Till Rohrmann <trohrm...@apache.org> > wrote: > > > What I forgot to add is that we could tackle specifying the configuration > > fully in an incremental way and that the full specification should be the > > desired end state. > > > > On Thu, Aug 29, 2019 at 1:33 PM Till Rohrmann <trohrm...@apache.org> > > wrote: > > > > > I think our goal should be that the configuration is fully specified > when > > > the process is started. By considering the internal calculation step to > > be > > > rather validate existing values and calculate missing ones, these two > > > proposal shouldn't even conflict (given determinism). > > > > > > Since we don't want to change an existing flink-conf.yaml, specifying > the > > > full configuration would require to pass in the options differently. > > > > > > One way could be the ENV variables approach. The reason why I'm trying > to > > > exclude this feature from the FLIP is that I believe it needs a bit > more > > > discussion. Just some questions which come to my mind: What would be > the > > > exact format (FLINK_KEY_NAME)? Would we support a dot separator which > is > > > supported by some systems (FLINK.KEY.NAME)? If we accept the dot > > > separator what would be the order of precedence if there are two ENV > > > variables defined (FLINK_KEY_NAME and FLINK.KEY.NAME)? What is the > > > precedence of env variable vs. dynamic configuration value specified > via > > -D? > > > > > > Another approach could be to pass in the dynamic configuration values > via > > > `-Dkey=value` to the Flink process. For that we don't have to change > > > anything because the functionality already exists. > > > > > > Cheers, > > > Till > > > > > > On Thu, Aug 29, 2019 at 12:50 PM Stephan Ewen <se...@apache.org> > wrote: > > > > > >> I see. Under the assumption of strict determinism that should work. > > >> > > >> The original proposal had this point "don't compute inside the TM, > > compute > > >> outside and supply a full config", because that sounded more > intuitive. > > >> > > >> On Thu, Aug 29, 2019 at 12:15 PM Till Rohrmann <trohrm...@apache.org> > > >> wrote: > > >> > > >> > My understanding was that before starting the Flink process we call > a > > >> > utility which calculates these values. I assume that this utility > will > > >> do > > >> > the calculation based on a set of configured values (process memory, > > >> flink > > >> > memory, network memory etc.). Assuming that these values don't > differ > > >> from > > >> > the values with which the JVM is started, it should be possible to > > >> > recompute them in the Flink process in order to set the values. > > >> > > > >> > > > >> > > > >> > On Thu, Aug 29, 2019 at 11:29 AM Stephan Ewen <se...@apache.org> > > wrote: > > >> > > > >> > > When computing the values in the JVM process after it started, how > > >> would > > >> > > you deal with values like Max Direct Memory, Metaspace size. > native > > >> > memory > > >> > > reservation (reduce heap size), etc? All the values that are > > >> parameters > > >> > to > > >> > > the JVM process and that need to be supplied at process startup? > > >> > > > > >> > > On Wed, Aug 28, 2019 at 4:46 PM Till Rohrmann < > trohrm...@apache.org > > > > > >> > > wrote: > > >> > > > > >> > > > Thanks for the clarification. I have some more comments: > > >> > > > > > >> > > > - I would actually split the logic to compute the process memory > > >> > > > requirements and storing the values into two things. E.g. one > > could > > >> > name > > >> > > > the former TaskExecutorProcessUtility and the latter > > >> > > > TaskExecutorProcessMemory. But we can discuss this on the PR > since > > >> it's > > >> > > > just a naming detail. > > >> > > > > > >> > > > - Generally, I'm not opposed to making configuration values > > >> overridable > > >> > > by > > >> > > > ENV variables. I think this is a very good idea and makes the > > >> > > > configurability of Flink processes easier. However, I think that > > >> adding > > >> > > > this functionality should not be part of this FLIP because it > > would > > >> > > simply > > >> > > > widen the scope unnecessarily. > > >> > > > > > >> > > > The reasons why I believe it is unnecessary are the following: > For > > >> Yarn > > >> > > we > > >> > > > already create write a flink-conf.yaml which could be populated > > with > > >> > the > > >> > > > memory settings. For the other processes it should not make a > > >> > difference > > >> > > > whether the loaded Configuration is populated with the memory > > >> settings > > >> > > from > > >> > > > ENV variables or by using TaskExecutorProcessUtility to compute > > the > > >> > > missing > > >> > > > values from the loaded configuration. If the latter would not be > > >> > possible > > >> > > > (wrong or missing configuration values), then we should not have > > >> been > > >> > > able > > >> > > > to actually start the process in the first place. > > >> > > > > > >> > > > - Concerning the memory reservation: I agree with you that we > need > > >> the > > >> > > > memory reservation functionality to make streaming jobs work > with > > >> > > "managed" > > >> > > > memory. However, w/o this functionality the whole Flip would > > already > > >> > > bring > > >> > > > a good amount of improvements to our users when running batch > > jobs. > > >> > > > Moreover, by keeping the scope smaller we can complete the FLIP > > >> faster. > > >> > > > Hence, I would propose to address the memory reservation > > >> functionality > > >> > > as a > > >> > > > follow up FLIP (which Yu is working on if I'm not mistaken). > > >> > > > > > >> > > > Cheers, > > >> > > > Till > > >> > > > > > >> > > > On Wed, Aug 28, 2019 at 11:43 AM Yang Wang < > danrtsey...@gmail.com > > > > > >> > > wrote: > > >> > > > > > >> > > > > Just add my 2 cents. > > >> > > > > > > >> > > > > Using environment variables to override the configuration for > > >> > different > > >> > > > > taskmanagers is better. > > >> > > > > We do not need to generate dedicated flink-conf.yaml for all > > >> > > > taskmanagers. > > >> > > > > A common flink-conf.yam and different environment variables > are > > >> > enough. > > >> > > > > By reducing the distributed cached files, it could make > > launching > > >> a > > >> > > > > taskmanager faster. > > >> > > > > > > >> > > > > Stephan gives a good suggestion that we could move the logic > > into > > >> > > > > "GlobalConfiguration.loadConfig()" method. > > >> > > > > Maybe the client could also benefit from this. Different users > > do > > >> not > > >> > > > have > > >> > > > > to export FLINK_CONF_DIR to update few config options. > > >> > > > > > > >> > > > > > > >> > > > > Best, > > >> > > > > Yang > > >> > > > > > > >> > > > > Stephan Ewen <se...@apache.org> 于2019年8月28日周三 上午1:21写道： > > >> > > > > > > >> > > > > > One note on the Environment Variables and Configuration > > >> discussion. > > >> > > > > > > > >> > > > > > My understanding is that passed ENV variables are added to > the > > >> > > > > > configuration in the "GlobalConfiguration.loadConfig()" > method > > >> (or > > >> > > > > > similar). > > >> > > > > > For all the code inside Flink, it looks like the data was in > > the > > >> > > config > > >> > > > > to > > >> > > > > > start with, just that the scripts that compute the variables > > can > > >> > pass > > >> > > > the > > >> > > > > > values to the process without actually needing to write a > > file. > > >> > > > > > > > >> > > > > > For example the "GlobalConfiguration.loadConfig()" method > > would > > >> > take > > >> > > > any > > >> > > > > > ENV variable prefixed with "flink" and add it as a config > key. > > >> > > > > > "flink_taskmanager_memory_size=2g" would become > > >> > > > "taskmanager.memory.size: > > >> > > > > > 2g". > > >> > > > > > > > >> > > > > > > > >> > > > > > On Tue, Aug 27, 2019 at 4:05 PM Xintong Song < > > >> > tonysong...@gmail.com> > > >> > > > > > wrote: > > >> > > > > > > > >> > > > > > > Thanks for the comments, Till. > > >> > > > > > > > > >> > > > > > > I've also seen your comments on the wiki page, but let's > > keep > > >> the > > >> > > > > > > discussion here. > > >> > > > > > > > > >> > > > > > > - Regarding 'TaskExecutorSpecifics', how do you think > about > > >> > naming > > >> > > it > > >> > > > > > > 'TaskExecutorResourceSpecifics'. > > >> > > > > > > - Regarding passing memory configurations into task > > executors, > > >> > I'm > > >> > > in > > >> > > > > > favor > > >> > > > > > > of do it via environment variables rather than > > configurations, > > >> > with > > >> > > > the > > >> > > > > > > following two reasons. > > >> > > > > > > - It is easier to keep the memory options once calculate > > >> not to > > >> > > be > > >> > > > > > > changed with environment variables rather than > > configurations. > > >> > > > > > > - I'm not sure whether we should write the configuration > > in > > >> > > startup > > >> > > > > > > scripts. Writing changes into the configuration files when > > >> > running > > >> > > > the > > >> > > > > > > startup scripts does not sounds right to me. Or we could > > make > > >> a > > >> > > copy > > >> > > > of > > >> > > > > > > configuration files per flink cluster, and make the task > > >> executor > > >> > > to > > >> > > > > load > > >> > > > > > > from the copy, and clean up the copy after the cluster is > > >> > shutdown, > > >> > > > > which > > >> > > > > > > is complicated. (I think this is also what Stephan means > in > > >> his > > >> > > > comment > > >> > > > > > on > > >> > > > > > > the wiki page?) > > >> > > > > > > - Regarding reserving memory, I think this change should > be > > >> > > included > > >> > > > in > > >> > > > > > > this FLIP. I think a big part of motivations of this FLIP > is > > >> to > > >> > > unify > > >> > > > > > > memory configuration for streaming / batch and make it > easy > > >> for > > >> > > > > > configuring > > >> > > > > > > rocksdb memory. If we don't support memory reservation, > then > > >> > > > streaming > > >> > > > > > jobs > > >> > > > > > > cannot use managed memory (neither on-heap or off-heap), > > which > > >> > > makes > > >> > > > > this > > >> > > > > > > FLIP incomplete. > > >> > > > > > > - Regarding network memory, I think you are right. I think > > we > > >> > > > probably > > >> > > > > > > don't need to change network stack from using direct > memory > > to > > >> > > using > > >> > > > > > unsafe > > >> > > > > > > native memory. Network memory size is deterministic, > cannot > > be > > >> > > > reserved > > >> > > > > > as > > >> > > > > > > managed memory does, and cannot be overused. I think it > also > > >> > works > > >> > > if > > >> > > > > we > > >> > > > > > > simply keep using direct memory for network and include it > > in > > >> jvm > > >> > > max > > >> > > > > > > direct memory size. > > >> > > > > > > > > >> > > > > > > Thank you~ > > >> > > > > > > > > >> > > > > > > Xintong Song > > >> > > > > > > > > >> > > > > > > > > >> > > > > > > > > >> > > > > > > On Tue, Aug 27, 2019 at 8:12 PM Till Rohrmann < > > >> > > trohrm...@apache.org> > > >> > > > > > > wrote: > > >> > > > > > > > > >> > > > > > > > Hi Xintong, > > >> > > > > > > > > > >> > > > > > > > thanks for addressing the comments and adding a more > > >> detailed > > >> > > > > > > > implementation plan. I have a couple of comments > > concerning > > >> the > > >> > > > > > > > implementation plan: > > >> > > > > > > > > > >> > > > > > > > - The name `TaskExecutorSpecifics` is not really > > >> descriptive. > > >> > > > > Choosing > > >> > > > > > a > > >> > > > > > > > different name could help here. > > >> > > > > > > > - I'm not sure whether I would pass the memory > > >> configuration to > > >> > > the > > >> > > > > > > > TaskExecutor via environment variables. I think it would > > be > > >> > > better > > >> > > > to > > >> > > > > > > write > > >> > > > > > > > it into the configuration one uses to start the TM > > process. > > >> > > > > > > > - If possible, I would exclude the memory reservation > from > > >> this > > >> > > > FLIP > > >> > > > > > and > > >> > > > > > > > add this as part of a dedicated FLIP. > > >> > > > > > > > - If possible, then I would exclude changes to the > network > > >> > stack > > >> > > > from > > >> > > > > > > this > > >> > > > > > > > FLIP. Maybe we can simply say that the direct memory > > needed > > >> by > > >> > > the > > >> > > > > > > network > > >> > > > > > > > stack is the framework direct memory requirement. > Changing > > >> how > > >> > > the > > >> > > > > > memory > > >> > > > > > > > is allocated can happen in a second step. This would > keep > > >> the > > >> > > scope > > >> > > > > of > > >> > > > > > > this > > >> > > > > > > > FLIP smaller. > > >> > > > > > > > > > >> > > > > > > > Cheers, > > >> > > > > > > > Till > > >> > > > > > > > > > >> > > > > > > > On Thu, Aug 22, 2019 at 2:51 PM Xintong Song < > > >> > > > tonysong...@gmail.com> > > >> > > > > > > > wrote: > > >> > > > > > > > > > >> > > > > > > > > Hi everyone, > > >> > > > > > > > > > > >> > > > > > > > > I just updated the FLIP document on wiki [1], with the > > >> > > following > > >> > > > > > > changes. > > >> > > > > > > > > > > >> > > > > > > > > - Removed open question regarding MemorySegment > > >> > allocation. > > >> > > As > > >> > > > > > > > > discussed, we exclude this topic from the scope of > > this > > >> > > FLIP. > > >> > > > > > > > > - Updated content about JVM direct memory parameter > > >> > > according > > >> > > > to > > >> > > > > > > > recent > > >> > > > > > > > > discussions, and moved the other options to > "Rejected > > >> > > > > > Alternatives" > > >> > > > > > > > for > > >> > > > > > > > > the > > >> > > > > > > > > moment. > > >> > > > > > > > > - Added implementation steps. > > >> > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > Thank you~ > > >> > > > > > > > > > > >> > > > > > > > > Xintong Song > > >> > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > [1] > > >> > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > >> > > > https://cwiki.apache.org/confluence/display/FLINK/FLIP-49%3A+Unified+Memory+Configuration+for+TaskExecutors > > >> > > > > > > > > > > >> > > > > > > > > On Mon, Aug 19, 2019 at 7:16 PM Stephan Ewen < > > >> > se...@apache.org > > >> > > > > > >> > > > > > wrote: > > >> > > > > > > > > > > >> > > > > > > > > > @Xintong: Concerning "wait for memory users before > > task > > >> > > dispose > > >> > > > > and > > >> > > > > > > > > memory > > >> > > > > > > > > > release": I agree, that's how it should be. Let's > try > > it > > >> > out. > > >> > > > > > > > > > > > >> > > > > > > > > > @Xintong @Jingsong: Concerning " JVM does not wait > for > > >> GC > > >> > > when > > >> > > > > > > > allocating > > >> > > > > > > > > > direct memory buffer": There seems to be pretty > > >> elaborate > > >> > > logic > > >> > > > > to > > >> > > > > > > free > > >> > > > > > > > > > buffers when allocating new ones. See > > >> > > > > > > > > > > > >> > > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > >> > > > http://hg.openjdk.java.net/jdk8u/jdk8u-dev/jdk/file/tip/src/share/classes/java/nio/Bits.java#l643 > > >> > > > > > > > > > > > >> > > > > > > > > > @Till: Maybe. If we assume that the JVM default > works > > >> (like > > >> > > > going > > >> > > > > > > with > > >> > > > > > > > > > option 2 and not setting "-XX:MaxDirectMemorySize" > at > > >> all), > > >> > > > then > > >> > > > > I > > >> > > > > > > > think > > >> > > > > > > > > it > > >> > > > > > > > > > should be okay to set "-XX:MaxDirectMemorySize" to > > >> > > > > > > > > > "off_heap_managed_memory + direct_memory" even if we > > use > > >> > > > RocksDB. > > >> > > > > > > That > > >> > > > > > > > > is a > > >> > > > > > > > > > big if, though, I honestly have no idea :D Would be > > >> good to > > >> > > > > > > understand > > >> > > > > > > > > > this, though, because this would affect option (2) > and > > >> > option > > >> > > > > > (1.2). > > >> > > > > > > > > > > > >> > > > > > > > > > On Mon, Aug 19, 2019 at 4:44 PM Xintong Song < > > >> > > > > > tonysong...@gmail.com> > > >> > > > > > > > > > wrote: > > >> > > > > > > > > > > > >> > > > > > > > > > > Thanks for the inputs, Jingsong. > > >> > > > > > > > > > > > > >> > > > > > > > > > > Let me try to summarize your points. Please > correct > > >> me if > > >> > > I'm > > >> > > > > > > wrong. > > >> > > > > > > > > > > > > >> > > > > > > > > > > - Memory consumers should always avoid > returning > > >> > memory > > >> > > > > > segments > > >> > > > > > > > to > > >> > > > > > > > > > > memory manager while there are still un-cleaned > > >> > > > structures / > > >> > > > > > > > threads > > >> > > > > > > > > > > that > > >> > > > > > > > > > > may use the memory. Otherwise, it would cause > > >> serious > > >> > > > > problems > > >> > > > > > > by > > >> > > > > > > > > > having > > >> > > > > > > > > > > multiple consumers trying to use the same > memory > > >> > > segment. > > >> > > > > > > > > > > - JVM does not wait for GC when allocating > direct > > >> > memory > > >> > > > > > buffer. > > >> > > > > > > > > > > Therefore even we set proper max direct memory > > size > > >> > > limit, > > >> > > > > we > > >> > > > > > > may > > >> > > > > > > > > > still > > >> > > > > > > > > > > encounter direct memory oom if the GC cleaning > > >> memory > > >> > > > slower > > >> > > > > > > than > > >> > > > > > > > > the > > >> > > > > > > > > > > direct memory allocation. > > >> > > > > > > > > > > > > >> > > > > > > > > > > Am I understanding this correctly? > > >> > > > > > > > > > > > > >> > > > > > > > > > > Thank you~ > > >> > > > > > > > > > > > > >> > > > > > > > > > > Xintong Song > > >> > > > > > > > > > > > > >> > > > > > > > > > > > > >> > > > > > > > > > > > > >> > > > > > > > > > > On Mon, Aug 19, 2019 at 4:21 PM JingsongLee < > > >> > > > > > > lzljs3620...@aliyun.com > > >> > > > > > > > > > > .invalid> > > >> > > > > > > > > > > wrote: > > >> > > > > > > > > > > > > >> > > > > > > > > > > > Hi stephan: > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > About option 2: > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > if additional threads not cleanly shut down > before > > >> we > > >> > can > > >> > > > > exit > > >> > > > > > > the > > >> > > > > > > > > > task: > > >> > > > > > > > > > > > In the current case of memory reuse, it has > freed > > up > > >> > the > > >> > > > > memory > > >> > > > > > > it > > >> > > > > > > > > > > > uses. If this memory is used by other tasks and > > >> > > > asynchronous > > >> > > > > > > > threads > > >> > > > > > > > > > > > of exited task may still be writing, there will > > be > > >> > > > > concurrent > > >> > > > > > > > > security > > >> > > > > > > > > > > > problems, and even lead to errors in user > > computing > > >> > > > results. > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > So I think this is a serious and intolerable > bug, > > No > > >> > > matter > > >> > > > > > what > > >> > > > > > > > the > > >> > > > > > > > > > > > option is, it should be avoided. > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > About direct memory cleaned by GC: > > >> > > > > > > > > > > > I don't think it is a good idea, I've > encountered > > so > > >> > many > > >> > > > > > > > situations > > >> > > > > > > > > > > > that it's too late for GC to cause DirectMemory > > >> OOM. > > >> > > > Release > > >> > > > > > and > > >> > > > > > > > > > > > allocate DirectMemory depend on the type of > user > > >> job, > > >> > > > which > > >> > > > > is > > >> > > > > > > > > > > > often beyond our control. > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > Best, > > >> > > > > > > > > > > > Jingsong Lee > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > >> > ------------------------------------------------------------------ > > >> > > > > > > > > > > > From:Stephan Ewen <se...@apache.org> > > >> > > > > > > > > > > > Send Time:2019年8月19日(星期一) 15:56 > > >> > > > > > > > > > > > To:dev <dev@flink.apache.org> > > >> > > > > > > > > > > > Subject:Re: [DISCUSS] FLIP-49: Unified Memory > > >> > > Configuration > > >> > > > > for > > >> > > > > > > > > > > > TaskExecutors > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > My main concern with option 2 (manually release > > >> memory) > > >> > > is > > >> > > > > that > > >> > > > > > > > > > segfaults > > >> > > > > > > > > > > > in the JVM send off all sorts of alarms on user > > >> ends. > > >> > So > > >> > > we > > >> > > > > > need > > >> > > > > > > to > > >> > > > > > > > > > > > guarantee that this never happens. > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > The trickyness is in tasks that uses data > > >> structures / > > >> > > > > > algorithms > > >> > > > > > > > > with > > >> > > > > > > > > > > > additional threads, like hash table spill/read > and > > >> > > sorting > > >> > > > > > > threads. > > >> > > > > > > > > We > > >> > > > > > > > > > > need > > >> > > > > > > > > > > > to ensure that these cleanly shut down before we > > can > > >> > exit > > >> > > > the > > >> > > > > > > task. > > >> > > > > > > > > > > > I am not sure that we have that guaranteed > > already, > > >> > > that's > > >> > > > > why > > >> > > > > > > > option > > >> > > > > > > > > > 1.1 > > >> > > > > > > > > > > > seemed simpler to me. > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > On Mon, Aug 19, 2019 at 3:42 PM Xintong Song < > > >> > > > > > > > tonysong...@gmail.com> > > >> > > > > > > > > > > > wrote: > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > Thanks for the comments, Stephan. Summarized > in > > >> this > > >> > > way > > >> > > > > > really > > >> > > > > > > > > makes > > >> > > > > > > > > > > > > things easier to understand. > > >> > > > > > > > > > > > > > > >> > > > > > > > > > > > > I'm in favor of option 2, at least for the > > >> moment. I > > >> > > > think > > >> > > > > it > > >> > > > > > > is > > >> > > > > > > > > not > > >> > > > > > > > > > > that > > >> > > > > > > > > > > > > difficult to keep it segfault safe for memory > > >> > manager, > > >> > > as > > >> > > > > > long > > >> > > > > > > as > > >> > > > > > > > > we > > >> > > > > > > > > > > > always > > >> > > > > > > > > > > > > de-allocate the memory segment when it is > > released > > >> > from > > >> > > > the > > >> > > > > > > > memory > > >> > > > > > > > > > > > > consumers. Only if the memory consumer > continue > > >> using > > >> > > the > > >> > > > > > > buffer > > >> > > > > > > > of > > >> > > > > > > > > > > > memory > > >> > > > > > > > > > > > > segment after releasing it, in which case we > do > > >> want > > >> > > the > > >> > > > > job > > >> > > > > > to > > >> > > > > > > > > fail > > >> > > > > > > > > > so > > >> > > > > > > > > > > > we > > >> > > > > > > > > > > > > detect the memory leak early. > > >> > > > > > > > > > > > > > > >> > > > > > > > > > > > > For option 1.2, I don't think this is a good > > idea. > > >> > Not > > >> > > > only > > >> > > > > > > > because > > >> > > > > > > > > > the > > >> > > > > > > > > > > > > assumption (regular GC is enough to clean > direct > > >> > > buffers) > > >> > > > > may > > >> > > > > > > not > > >> > > > > > > > > > > always > > >> > > > > > > > > > > > be > > >> > > > > > > > > > > > > true, but also it makes harder for finding > > >> problems > > >> > in > > >> > > > > cases > > >> > > > > > of > > >> > > > > > > > > > memory > > >> > > > > > > > > > > > > overuse. E.g., user configured some direct > > memory > > >> for > > >> > > the > > >> > > > > > user > > >> > > > > > > > > > > libraries. > > >> > > > > > > > > > > > > If the library actually use more direct memory > > >> then > > >> > > > > > configured, > > >> > > > > > > > > which > > >> > > > > > > > > > > > > cannot be cleaned by GC because they are still > > in > > >> > use, > > >> > > > may > > >> > > > > > lead > > >> > > > > > > > to > > >> > > > > > > > > > > > overuse > > >> > > > > > > > > > > > > of the total container memory. In that case, > if > > it > > >> > > didn't > > >> > > > > > touch > > >> > > > > > > > the > > >> > > > > > > > > > JVM > > >> > > > > > > > > > > > > default max direct memory limit, we cannot > get a > > >> > direct > > >> > > > > > memory > > >> > > > > > > > OOM > > >> > > > > > > > > > and > > >> > > > > > > > > > > it > > >> > > > > > > > > > > > > will become super hard to understand which > part > > of > > >> > the > > >> > > > > > > > > configuration > > >> > > > > > > > > > > need > > >> > > > > > > > > > > > > to be updated. > > >> > > > > > > > > > > > > > > >> > > > > > > > > > > > > For option 1.1, it has the similar problem as > > >> 1.2, if > > >> > > the > > >> > > > > > > > exceeded > > >> > > > > > > > > > > direct > > >> > > > > > > > > > > > > memory does not reach the max direct memory > > limit > > >> > > > specified > > >> > > > > > by > > >> > > > > > > > the > > >> > > > > > > > > > > > > dedicated parameter. I think it is slightly > > better > > >> > than > > >> > > > > 1.2, > > >> > > > > > > only > > >> > > > > > > > > > > because > > >> > > > > > > > > > > > > we can tune the parameter. > > >> > > > > > > > > > > > > > > >> > > > > > > > > > > > > Thank you~ > > >> > > > > > > > > > > > > > > >> > > > > > > > > > > > > Xintong Song > > >> > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > >> > > > > > > > > > > > > On Mon, Aug 19, 2019 at 2:53 PM Stephan Ewen < > > >> > > > > > se...@apache.org > > >> > > > > > > > > > >> > > > > > > > > > wrote: > > >> > > > > > > > > > > > > > > >> > > > > > > > > > > > > > About the "-XX:MaxDirectMemorySize" > > discussion, > > >> > maybe > > >> > > > let > > >> > > > > > me > > >> > > > > > > > > > > summarize > > >> > > > > > > > > > > > > it a > > >> > > > > > > > > > > > > > bit differently: > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > We have the following two options: > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > (1) We let MemorySegments be de-allocated by > > the > > >> > GC. > > >> > > > That > > >> > > > > > > makes > > >> > > > > > > > > it > > >> > > > > > > > > > > > > segfault > > >> > > > > > > > > > > > > > safe. But then we need a way to trigger GC > in > > >> case > > >> > > > > > > > de-allocation > > >> > > > > > > > > > and > > >> > > > > > > > > > > > > > re-allocation of a bunch of segments happens > > >> > quickly, > > >> > > > > which > > >> > > > > > > is > > >> > > > > > > > > > often > > >> > > > > > > > > > > > the > > >> > > > > > > > > > > > > > case during batch scheduling or task > restart. > > >> > > > > > > > > > > > > > - The "-XX:MaxDirectMemorySize" (option > 1.1) > > >> is > > >> > one > > >> > > > way > > >> > > > > > to > > >> > > > > > > do > > >> > > > > > > > > > this > > >> > > > > > > > > > > > > > - Another way could be to have a dedicated > > >> > > > bookkeeping > > >> > > > > in > > >> > > > > > > the > > >> > > > > > > > > > > > > > MemoryManager (option 1.2), so that this is > a > > >> > number > > >> > > > > > > > independent > > >> > > > > > > > > of > > >> > > > > > > > > > > the > > >> > > > > > > > > > > > > > "-XX:MaxDirectMemorySize" parameter. > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > (2) We manually allocate and de-allocate the > > >> memory > > >> > > for > > >> > > > > the > > >> > > > > > > > > > > > > MemorySegments > > >> > > > > > > > > > > > > > (option 2). That way we need not worry about > > >> > > triggering > > >> > > > > GC > > >> > > > > > by > > >> > > > > > > > > some > > >> > > > > > > > > > > > > > threshold or bookkeeping, but it is harder > to > > >> > prevent > > >> > > > > > > > segfaults. > > >> > > > > > > > > We > > >> > > > > > > > > > > > need > > >> > > > > > > > > > > > > to > > >> > > > > > > > > > > > > > be very careful about when we release the > > memory > > >> > > > segments > > >> > > > > > > (only > > >> > > > > > > > > in > > >> > > > > > > > > > > the > > >> > > > > > > > > > > > > > cleanup phase of the main thread). > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > If we go with option 1.1, we probably need > to > > >> set > > >> > > > > > > > > > > > > > "-XX:MaxDirectMemorySize" to > > >> > > "off_heap_managed_memory + > > >> > > > > > > > > > > direct_memory" > > >> > > > > > > > > > > > > and > > >> > > > > > > > > > > > > > have "direct_memory" as a separate reserved > > >> memory > > >> > > > pool. > > >> > > > > > > > Because > > >> > > > > > > > > if > > >> > > > > > > > > > > we > > >> > > > > > > > > > > > > just > > >> > > > > > > > > > > > > > set "-XX:MaxDirectMemorySize" to > > >> > > > > "off_heap_managed_memory + > > >> > > > > > > > > > > > > jvm_overhead", > > >> > > > > > > > > > > > > > then there will be times when that entire > > >> memory is > > >> > > > > > allocated > > >> > > > > > > > by > > >> > > > > > > > > > > direct > > >> > > > > > > > > > > > > > buffers and we have nothing left for the JVM > > >> > > overhead. > > >> > > > So > > >> > > > > > we > > >> > > > > > > > > either > > >> > > > > > > > > > > > need > > >> > > > > > > > > > > > > a > > >> > > > > > > > > > > > > > way to compensate for that (again some > safety > > >> > margin > > >> > > > > cutoff > > >> > > > > > > > > value) > > >> > > > > > > > > > or > > >> > > > > > > > > > > > we > > >> > > > > > > > > > > > > > will exceed container memory. > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > If we go with option 1.2, we need to be > aware > > >> that > > >> > it > > >> > > > > takes > > >> > > > > > > > > > elaborate > > >> > > > > > > > > > > > > logic > > >> > > > > > > > > > > > > > to push recycling of direct buffers without > > >> always > > >> > > > > > > triggering a > > >> > > > > > > > > > full > > >> > > > > > > > > > > > GC. > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > My first guess is that the options will be > > >> easiest > > >> > to > > >> > > > do > > >> > > > > in > > >> > > > > > > the > > >> > > > > > > > > > > > following > > >> > > > > > > > > > > > > > order: > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > - Option 1.1 with a dedicated > direct_memory > > >> > > > parameter, > > >> > > > > as > > >> > > > > > > > > > discussed > > >> > > > > > > > > > > > > > above. We would need to find a way to set > the > > >> > > > > direct_memory > > >> > > > > > > > > > parameter > > >> > > > > > > > > > > > by > > >> > > > > > > > > > > > > > default. We could start with 64 MB and see > how > > >> it > > >> > > goes > > >> > > > in > > >> > > > > > > > > practice. > > >> > > > > > > > > > > One > > >> > > > > > > > > > > > > > danger I see is that setting this loo low > can > > >> > cause a > > >> > > > > bunch > > >> > > > > > > of > > >> > > > > > > > > > > > additional > > >> > > > > > > > > > > > > > GCs compared to before (we need to watch > this > > >> > > > carefully). > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > - Option 2. It is actually quite simple to > > >> > > implement, > > >> > > > > we > > >> > > > > > > > could > > >> > > > > > > > > > try > > >> > > > > > > > > > > > how > > >> > > > > > > > > > > > > > segfault safe we are at the moment. > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > - Option 1.2: We would not touch the > > >> > > > > > > > "-XX:MaxDirectMemorySize" > > >> > > > > > > > > > > > > parameter > > >> > > > > > > > > > > > > > at all and assume that all the direct memory > > >> > > > allocations > > >> > > > > > that > > >> > > > > > > > the > > >> > > > > > > > > > JVM > > >> > > > > > > > > > > > and > > >> > > > > > > > > > > > > > Netty do are infrequent enough to be cleaned > > up > > >> > fast > > >> > > > > enough > > >> > > > > > > > > through > > >> > > > > > > > > > > > > regular > > >> > > > > > > > > > > > > > GC. I am not sure if that is a valid > > assumption, > > >> > > > though. > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > Best, > > >> > > > > > > > > > > > > > Stephan > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > On Fri, Aug 16, 2019 at 2:16 PM Xintong > Song < > > >> > > > > > > > > > tonysong...@gmail.com> > > >> > > > > > > > > > > > > > wrote: > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > Thanks for sharing your opinion Till. > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > I'm also in favor of alternative 2. I was > > >> > wondering > > >> > > > > > whether > > >> > > > > > > > we > > >> > > > > > > > > > can > > >> > > > > > > > > > > > > avoid > > >> > > > > > > > > > > > > > > using Unsafe.allocate() for off-heap > managed > > >> > memory > > >> > > > and > > >> > > > > > > > network > > >> > > > > > > > > > > > memory > > >> > > > > > > > > > > > > > with > > >> > > > > > > > > > > > > > > alternative 3. But after giving it a > second > > >> > > thought, > > >> > > > I > > >> > > > > > > think > > >> > > > > > > > > even > > >> > > > > > > > > > > for > > >> > > > > > > > > > > > > > > alternative 3 using direct memory for > > off-heap > > >> > > > managed > > >> > > > > > > memory > > >> > > > > > > > > > could > > >> > > > > > > > > > > > > cause > > >> > > > > > > > > > > > > > > problems. > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > Hi Yang, > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > Regarding your concern, I think what > > proposed > > >> in > > >> > > this > > >> > > > > > FLIP > > >> > > > > > > it > > >> > > > > > > > > to > > >> > > > > > > > > > > have > > >> > > > > > > > > > > > > > both > > >> > > > > > > > > > > > > > > off-heap managed memory and network memory > > >> > > allocated > > >> > > > > > > through > > >> > > > > > > > > > > > > > > Unsafe.allocate(), which means they are > > >> > practically > > >> > > > > > native > > >> > > > > > > > > memory > > >> > > > > > > > > > > and > > >> > > > > > > > > > > > > not > > >> > > > > > > > > > > > > > > limited by JVM max direct memory. The only > > >> parts > > >> > of > > >> > > > > > memory > > >> > > > > > > > > > limited > > >> > > > > > > > > > > by > > >> > > > > > > > > > > > > JVM > > >> > > > > > > > > > > > > > > max direct memory are task off-heap memory > > and > > >> > JVM > > >> > > > > > > overhead, > > >> > > > > > > > > > which > > >> > > > > > > > > > > > are > > >> > > > > > > > > > > > > > > exactly alternative 2 suggests to set the > > JVM > > >> max > > >> > > > > direct > > >> > > > > > > > memory > > >> > > > > > > > > > to. > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > Thank you~ > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > Xintong Song > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > On Fri, Aug 16, 2019 at 1:48 PM Till > > Rohrmann > > >> < > > >> > > > > > > > > > > trohrm...@apache.org> > > >> > > > > > > > > > > > > > > wrote: > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > Thanks for the clarification Xintong. I > > >> > > understand > > >> > > > > the > > >> > > > > > > two > > >> > > > > > > > > > > > > alternatives > > >> > > > > > > > > > > > > > > > now. > > >> > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > I would be in favour of option 2 because > > it > > >> > makes > > >> > > > > > things > > >> > > > > > > > > > > explicit. > > >> > > > > > > > > > > > If > > >> > > > > > > > > > > > > > we > > >> > > > > > > > > > > > > > > > don't limit the direct memory, I fear > that > > >> we > > >> > > might > > >> > > > > end > > >> > > > > > > up > > >> > > > > > > > > in a > > >> > > > > > > > > > > > > similar > > >> > > > > > > > > > > > > > > > situation as we are currently in: The > user > > >> > might > > >> > > > see > > >> > > > > > that > > >> > > > > > > > her > > >> > > > > > > > > > > > process > > >> > > > > > > > > > > > > > > gets > > >> > > > > > > > > > > > > > > > killed by the OS and does not know why > > this > > >> is > > >> > > the > > >> > > > > > case. > > >> > > > > > > > > > > > > Consequently, > > >> > > > > > > > > > > > > > > she > > >> > > > > > > > > > > > > > > > tries to decrease the process memory > size > > >> > > (similar > > >> > > > to > > >> > > > > > > > > > increasing > > >> > > > > > > > > > > > the > > >> > > > > > > > > > > > > > > cutoff > > >> > > > > > > > > > > > > > > > ratio) in order to accommodate for the > > extra > > >> > > direct > > >> > > > > > > memory. > > >> > > > > > > > > > Even > > >> > > > > > > > > > > > > worse, > > >> > > > > > > > > > > > > > > she > > >> > > > > > > > > > > > > > > > tries to decrease memory budgets which > are > > >> not > > >> > > > fully > > >> > > > > > used > > >> > > > > > > > and > > >> > > > > > > > > > > hence > > >> > > > > > > > > > > > > > won't > > >> > > > > > > > > > > > > > > > change the overall memory consumption. > > >> > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > Cheers, > > >> > > > > > > > > > > > > > > > Till > > >> > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > On Fri, Aug 16, 2019 at 11:01 AM Xintong > > >> Song < > > >> > > > > > > > > > > > tonysong...@gmail.com > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > wrote: > > >> > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > Let me explain this with a concrete > > >> example > > >> > > Till. > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > Let's say we have the following > > scenario. > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > Total Process Memory: 1GB > > >> > > > > > > > > > > > > > > > > JVM Direct Memory (Task Off-Heap > Memory > > + > > >> JVM > > >> > > > > > > Overhead): > > >> > > > > > > > > > 200MB > > >> > > > > > > > > > > > > > > > > Other Memory (JVM Heap Memory, JVM > > >> Metaspace, > > >> > > > > > Off-Heap > > >> > > > > > > > > > Managed > > >> > > > > > > > > > > > > Memory > > >> > > > > > > > > > > > > > > and > > >> > > > > > > > > > > > > > > > > Network Memory): 800MB > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > For alternative 2, we set > > >> > > -XX:MaxDirectMemorySize > > >> > > > > to > > >> > > > > > > > 200MB. > > >> > > > > > > > > > > > > > > > > For alternative 3, we set > > >> > > -XX:MaxDirectMemorySize > > >> > > > > to > > >> > > > > > a > > >> > > > > > > > very > > >> > > > > > > > > > > large > > >> > > > > > > > > > > > > > > value, > > >> > > > > > > > > > > > > > > > > let's say 1TB. > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > If the actual direct memory usage of > > Task > > >> > > > Off-Heap > > >> > > > > > > Memory > > >> > > > > > > > > and > > >> > > > > > > > > > > JVM > > >> > > > > > > > > > > > > > > > Overhead > > >> > > > > > > > > > > > > > > > > do not exceed 200MB, then alternative > 2 > > >> and > > >> > > > > > > alternative 3 > > >> > > > > > > > > > > should > > >> > > > > > > > > > > > > have > > >> > > > > > > > > > > > > > > the > > >> > > > > > > > > > > > > > > > > same utility. Setting larger > > >> > > > > -XX:MaxDirectMemorySize > > >> > > > > > > will > > >> > > > > > > > > not > > >> > > > > > > > > > > > > reduce > > >> > > > > > > > > > > > > > > the > > >> > > > > > > > > > > > > > > > > sizes of the other memory pools. > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > If the actual direct memory usage of > > Task > > >> > > > Off-Heap > > >> > > > > > > Memory > > >> > > > > > > > > and > > >> > > > > > > > > > > JVM > > >> > > > > > > > > > > > > > > > > Overhead potentially exceed 200MB, > then > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > - Alternative 2 suffers from > frequent > > >> OOM. > > >> > > To > > >> > > > > > avoid > > >> > > > > > > > > that, > > >> > > > > > > > > > > the > > >> > > > > > > > > > > > > only > > >> > > > > > > > > > > > > > > > thing > > >> > > > > > > > > > > > > > > > > user can do is to modify the > > >> configuration > > >> > > and > > >> > > > > > > > increase > > >> > > > > > > > > > JVM > > >> > > > > > > > > > > > > Direct > > >> > > > > > > > > > > > > > > > > Memory > > >> > > > > > > > > > > > > > > > > (Task Off-Heap Memory + JVM > > Overhead). > > >> > Let's > > >> > > > say > > >> > > > > > > that > > >> > > > > > > > > user > > >> > > > > > > > > > > > > > increases > > >> > > > > > > > > > > > > > > > JVM > > >> > > > > > > > > > > > > > > > > Direct Memory to 250MB, this will > > >> reduce > > >> > the > > >> > > > > total > > >> > > > > > > > size > > >> > > > > > > > > of > > >> > > > > > > > > > > > other > > >> > > > > > > > > > > > > > > > memory > > >> > > > > > > > > > > > > > > > > pools to 750MB, given the total > > process > > >> > > memory > > >> > > > > > > remains > > >> > > > > > > > > > 1GB. > > >> > > > > > > > > > > > > > > > > - For alternative 3, there is no > > >> chance of > > >> > > > > direct > > >> > > > > > > OOM. > > >> > > > > > > > > > There > > >> > > > > > > > > > > > are > > >> > > > > > > > > > > > > > > > chances > > >> > > > > > > > > > > > > > > > > of exceeding the total process > memory > > >> > limit, > > >> > > > but > > >> > > > > > > given > > >> > > > > > > > > > that > > >> > > > > > > > > > > > the > > >> > > > > > > > > > > > > > > > process > > >> > > > > > > > > > > > > > > > > may > > >> > > > > > > > > > > > > > > > > not use up all the reserved native > > >> memory > > >> > > > > > (Off-Heap > > >> > > > > > > > > > Managed > > >> > > > > > > > > > > > > > Memory, > > >> > > > > > > > > > > > > > > > > Network > > >> > > > > > > > > > > > > > > > > Memory, JVM Metaspace), if the > actual > > >> > direct > > >> > > > > > memory > > >> > > > > > > > > usage > > >> > > > > > > > > > is > > >> > > > > > > > > > > > > > > slightly > > >> > > > > > > > > > > > > > > > > above > > >> > > > > > > > > > > > > > > > > yet very close to 200MB, user > > probably > > >> do > > >> > > not > > >> > > > > need > > >> > > > > > > to > > >> > > > > > > > > > change > > >> > > > > > > > > > > > the > > >> > > > > > > > > > > > > > > > > configurations. > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > Therefore, I think from the user's > > >> > > perspective, a > > >> > > > > > > > feasible > > >> > > > > > > > > > > > > > > configuration > > >> > > > > > > > > > > > > > > > > for alternative 2 may lead to lower > > >> resource > > >> > > > > > > utilization > > >> > > > > > > > > > > compared > > >> > > > > > > > > > > > > to > > >> > > > > > > > > > > > > > > > > alternative 3. > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > Thank you~ > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > Xintong Song > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > On Fri, Aug 16, 2019 at 10:28 AM Till > > >> > Rohrmann > > >> > > < > > >> > > > > > > > > > > > > trohrm...@apache.org > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > wrote: > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > I guess you have to help me > understand > > >> the > > >> > > > > > difference > > >> > > > > > > > > > between > > >> > > > > > > > > > > > > > > > > alternative 2 > > >> > > > > > > > > > > > > > > > > > and 3 wrt to memory under > utilization > > >> > > Xintong. > > >> > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > - Alternative 2: set > > >> XX:MaxDirectMemorySize > > >> > > to > > >> > > > > Task > > >> > > > > > > > > > Off-Heap > > >> > > > > > > > > > > > > Memory > > >> > > > > > > > > > > > > > > and > > >> > > > > > > > > > > > > > > > > JVM > > >> > > > > > > > > > > > > > > > > > Overhead. Then there is the risk > that > > >> this > > >> > > size > > >> > > > > is > > >> > > > > > > too > > >> > > > > > > > > low > > >> > > > > > > > > > > > > > resulting > > >> > > > > > > > > > > > > > > > in a > > >> > > > > > > > > > > > > > > > > > lot of garbage collection and > > >> potentially > > >> > an > > >> > > > OOM. > > >> > > > > > > > > > > > > > > > > > - Alternative 3: set > > >> XX:MaxDirectMemorySize > > >> > > to > > >> > > > > > > > something > > >> > > > > > > > > > > larger > > >> > > > > > > > > > > > > > than > > >> > > > > > > > > > > > > > > > > > alternative 2. This would of course > > >> reduce > > >> > > the > > >> > > > > > sizes > > >> > > > > > > of > > >> > > > > > > > > the > > >> > > > > > > > > > > > other > > >> > > > > > > > > > > > > > > > memory > > >> > > > > > > > > > > > > > > > > > types. > > >> > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > How would alternative 2 now result > in > > an > > >> > > under > > >> > > > > > > > > utilization > > >> > > > > > > > > > of > > >> > > > > > > > > > > > > > memory > > >> > > > > > > > > > > > > > > > > > compared to alternative 3? If > > >> alternative 3 > > >> > > > > > strictly > > >> > > > > > > > > sets a > > >> > > > > > > > > > > > > higher > > >> > > > > > > > > > > > > > > max > > >> > > > > > > > > > > > > > > > > > direct memory size and we use only > > >> little, > > >> > > > then I > > >> > > > > > > would > > >> > > > > > > > > > > expect > > >> > > > > > > > > > > > > that > > >> > > > > > > > > > > > > > > > > > alternative 3 results in memory > under > > >> > > > > utilization. > > >> > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > Cheers, > > >> > > > > > > > > > > > > > > > > > Till > > >> > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > On Tue, Aug 13, 2019 at 4:19 PM Yang > > >> Wang < > > >> > > > > > > > > > > > danrtsey...@gmail.com > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > wrote: > > >> > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > Hi xintong,till > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > Native and Direct Memory > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > My point is setting a very large > max > > >> > direct > > >> > > > > > memory > > >> > > > > > > > size > > >> > > > > > > > > > > when > > >> > > > > > > > > > > > we > > >> > > > > > > > > > > > > > do > > >> > > > > > > > > > > > > > > > not > > >> > > > > > > > > > > > > > > > > > > differentiate direct and native > > >> memory. > > >> > If > > >> > > > the > > >> > > > > > > direct > > >> > > > > > > > > > > > > > > > memory,including > > >> > > > > > > > > > > > > > > > > > user > > >> > > > > > > > > > > > > > > > > > > direct memory and framework direct > > >> > > > memory,could > > >> > > > > > be > > >> > > > > > > > > > > calculated > > >> > > > > > > > > > > > > > > > > > > correctly,then > > >> > > > > > > > > > > > > > > > > > > i am in favor of setting direct > > memory > > >> > with > > >> > > > > fixed > > >> > > > > > > > > value. > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > Memory Calculation > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > I agree with xintong. For Yarn and > > >> k8s,we > > >> > > > need > > >> > > > > to > > >> > > > > > > > check > > >> > > > > > > > > > the > > >> > > > > > > > > > > > > > memory > > >> > > > > > > > > > > > > > > > > > > configurations in client to avoid > > >> > > submitting > > >> > > > > > > > > successfully > > >> > > > > > > > > > > and > > >> > > > > > > > > > > > > > > failing > > >> > > > > > > > > > > > > > > > > in > > >> > > > > > > > > > > > > > > > > > > the flink master. > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > Best, > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > Yang > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > Xintong Song < > tonysong...@gmail.com > > >> > > > > >于2019年8月13日 > > >> > > > > > > > > > 周二22:07写道： > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > Thanks for replying, Till. > > >> > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > About MemorySegment, I think you > > are > > >> > > right > > >> > > > > that > > >> > > > > > > we > > >> > > > > > > > > > should > > >> > > > > > > > > > > > not > > >> > > > > > > > > > > > > > > > include > > >> > > > > > > > > > > > > > > > > > > this > > >> > > > > > > > > > > > > > > > > > > > issue in the scope of this FLIP. > > >> This > > >> > > FLIP > > >> > > > > > should > > >> > > > > > > > > > > > concentrate > > >> > > > > > > > > > > > > > on > > >> > > > > > > > > > > > > > > > how > > >> > > > > > > > > > > > > > > > > to > > >> > > > > > > > > > > > > > > > > > > > configure memory pools for > > >> > TaskExecutors, > > >> > > > > with > > >> > > > > > > > > minimum > > >> > > > > > > > > > > > > > > involvement > > >> > > > > > > > > > > > > > > > on > > >> > > > > > > > > > > > > > > > > > how > > >> > > > > > > > > > > > > > > > > > > > memory consumers use it. > > >> > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > About direct memory, I think > > >> > alternative > > >> > > 3 > > >> > > > > may > > >> > > > > > > not > > >> > > > > > > > > > having > > >> > > > > > > > > > > > the > > >> > > > > > > > > > > > > > > same > > >> > > > > > > > > > > > > > > > > over > > >> > > > > > > > > > > > > > > > > > > > reservation issue that > > alternative 2 > > >> > > does, > > >> > > > > but > > >> > > > > > at > > >> > > > > > > > the > > >> > > > > > > > > > > cost > > >> > > > > > > > > > > > of > > >> > > > > > > > > > > > > > > risk > > >> > > > > > > > > > > > > > > > of > > >> > > > > > > > > > > > > > > > > > > over > > >> > > > > > > > > > > > > > > > > > > > using memory at the container > > level, > > >> > > which > > >> > > > is > > >> > > > > > not > > >> > > > > > > > > good. > > >> > > > > > > > > > > My > > >> > > > > > > > > > > > > > point > > >> > > > > > > > > > > > > > > is > > >> > > > > > > > > > > > > > > > > > that > > >> > > > > > > > > > > > > > > > > > > > both "Task Off-Heap Memory" and > > "JVM > > >> > > > > Overhead" > > >> > > > > > > are > > >> > > > > > > > > not > > >> > > > > > > > > > > easy > > >> > > > > > > > > > > > > to > > >> > > > > > > > > > > > > > > > > config. > > >> > > > > > > > > > > > > > > > > > > For > > >> > > > > > > > > > > > > > > > > > > > alternative 2, users might > > configure > > >> > them > > >> > > > > > higher > > >> > > > > > > > than > > >> > > > > > > > > > > what > > >> > > > > > > > > > > > > > > actually > > >> > > > > > > > > > > > > > > > > > > needed, > > >> > > > > > > > > > > > > > > > > > > > just to avoid getting a direct > > OOM. > > >> For > > >> > > > > > > alternative > > >> > > > > > > > > 3, > > >> > > > > > > > > > > > users > > >> > > > > > > > > > > > > do > > >> > > > > > > > > > > > > > > not > > >> > > > > > > > > > > > > > > > > get > > >> > > > > > > > > > > > > > > > > > > > direct OOM, so they may not > config > > >> the > > >> > > two > > >> > > > > > > options > > >> > > > > > > > > > > > > aggressively > > >> > > > > > > > > > > > > > > > high. > > >> > > > > > > > > > > > > > > > > > But > > >> > > > > > > > > > > > > > > > > > > > the consequences are risks of > > >> overall > > >> > > > > container > > >> > > > > > > > > memory > > >> > > > > > > > > > > > usage > > >> > > > > > > > > > > > > > > > exceeds > > >> > > > > > > > > > > > > > > > > > the > > >> > > > > > > > > > > > > > > > > > > > budget. > > >> > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > Thank you~ > > >> > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > Xintong Song > > >> > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > On Tue, Aug 13, 2019 at 9:39 AM > > Till > > >> > > > > Rohrmann < > > >> > > > > > > > > > > > > > > > trohrm...@apache.org> > > >> > > > > > > > > > > > > > > > > > > > wrote: > > >> > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > Thanks for proposing this FLIP > > >> > Xintong. > > >> > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > All in all I think it already > > >> looks > > >> > > quite > > >> > > > > > good. > > >> > > > > > > > > > > > Concerning > > >> > > > > > > > > > > > > > the > > >> > > > > > > > > > > > > > > > > first > > >> > > > > > > > > > > > > > > > > > > open > > >> > > > > > > > > > > > > > > > > > > > > question about allocating > memory > > >> > > > segments, > > >> > > > > I > > >> > > > > > > was > > >> > > > > > > > > > > > wondering > > >> > > > > > > > > > > > > > > > whether > > >> > > > > > > > > > > > > > > > > > this > > >> > > > > > > > > > > > > > > > > > > > is > > >> > > > > > > > > > > > > > > > > > > > > strictly necessary to do in > the > > >> > context > > >> > > > of > > >> > > > > > this > > >> > > > > > > > > FLIP > > >> > > > > > > > > > or > > >> > > > > > > > > > > > > > whether > > >> > > > > > > > > > > > > > > > > this > > >> > > > > > > > > > > > > > > > > > > > could > > >> > > > > > > > > > > > > > > > > > > > > be done as a follow up? > Without > > >> > knowing > > >> > > > all > > >> > > > > > > > > details, > > >> > > > > > > > > > I > > >> > > > > > > > > > > > > would > > >> > > > > > > > > > > > > > be > > >> > > > > > > > > > > > > > > > > > > concerned > > >> > > > > > > > > > > > > > > > > > > > > that we would widen the scope > of > > >> this > > >> > > > FLIP > > >> > > > > > too > > >> > > > > > > > much > > >> > > > > > > > > > > > because > > >> > > > > > > > > > > > > > we > > >> > > > > > > > > > > > > > > > > would > > >> > > > > > > > > > > > > > > > > > > have > > >> > > > > > > > > > > > > > > > > > > > > to touch all the existing call > > >> sites > > >> > of > > >> > > > the > > >> > > > > > > > > > > MemoryManager > > >> > > > > > > > > > > > > > where > > >> > > > > > > > > > > > > > > > we > > >> > > > > > > > > > > > > > > > > > > > allocate > > >> > > > > > > > > > > > > > > > > > > > > memory segments (this should > > >> mainly > > >> > be > > >> > > > > batch > > >> > > > > > > > > > > operators). > > >> > > > > > > > > > > > > The > > >> > > > > > > > > > > > > > > > > addition > > >> > > > > > > > > > > > > > > > > > > of > > >> > > > > > > > > > > > > > > > > > > > > the memory reservation call to > > the > > >> > > > > > > MemoryManager > > >> > > > > > > > > > should > > >> > > > > > > > > > > > not > > >> > > > > > > > > > > > > > be > > >> > > > > > > > > > > > > > > > > > affected > > >> > > > > > > > > > > > > > > > > > > > by > > >> > > > > > > > > > > > > > > > > > > > > this and I would hope that > this > > is > > >> > the > > >> > > > only > > >> > > > > > > point > > >> > > > > > > > > of > > >> > > > > > > > > > > > > > > interaction > > >> > > > > > > > > > > > > > > > a > > >> > > > > > > > > > > > > > > > > > > > > streaming job would have with > > the > > >> > > > > > > MemoryManager. > > >> > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > Concerning the second open > > >> question > > >> > > about > > >> > > > > > > setting > > >> > > > > > > > > or > > >> > > > > > > > > > > not > > >> > > > > > > > > > > > > > > setting > > >> > > > > > > > > > > > > > > > a > > >> > > > > > > > > > > > > > > > > > max > > >> > > > > > > > > > > > > > > > > > > > > direct memory limit, I would > > also > > >> be > > >> > > > > > interested > > >> > > > > > > > why > > >> > > > > > > > > > > Yang > > >> > > > > > > > > > > > > Wang > > >> > > > > > > > > > > > > > > > > thinks > > >> > > > > > > > > > > > > > > > > > > > > leaving it open would be best. > > My > > >> > > concern > > >> > > > > > about > > >> > > > > > > > > this > > >> > > > > > > > > > > > would > > >> > > > > > > > > > > > > be > > >> > > > > > > > > > > > > > > > that > > >> > > > > > > > > > > > > > > > > we > > >> > > > > > > > > > > > > > > > > > > > would > > >> > > > > > > > > > > > > > > > > > > > > be in a similar situation as > we > > >> are > > >> > now > > >> > > > > with > > >> > > > > > > the > > >> > > > > > > > > > > > > > > > > RocksDBStateBackend. > > >> > > > > > > > > > > > > > > > > > > If > > >> > > > > > > > > > > > > > > > > > > > > the different memory pools are > > not > > >> > > > clearly > > >> > > > > > > > > separated > > >> > > > > > > > > > > and > > >> > > > > > > > > > > > > can > > >> > > > > > > > > > > > > > > > spill > > >> > > > > > > > > > > > > > > > > > over > > >> > > > > > > > > > > > > > > > > > > > to > > >> > > > > > > > > > > > > > > > > > > > > a different pool, then it is > > quite > > >> > hard > > >> > > > to > > >> > > > > > > > > understand > > >> > > > > > > > > > > > what > > >> > > > > > > > > > > > > > > > exactly > > >> > > > > > > > > > > > > > > > > > > > causes a > > >> > > > > > > > > > > > > > > > > > > > > process to get killed for > using > > >> too > > >> > > much > > >> > > > > > > memory. > > >> > > > > > > > > This > > >> > > > > > > > > > > > could > > >> > > > > > > > > > > > > > > then > > >> > > > > > > > > > > > > > > > > > easily > > >> > > > > > > > > > > > > > > > > > > > > lead to a similar situation > what > > >> we > > >> > > have > > >> > > > > with > > >> > > > > > > the > > >> > > > > > > > > > > > > > cutoff-ratio. > > >> > > > > > > > > > > > > > > > So > > >> > > > > > > > > > > > > > > > > > why > > >> > > > > > > > > > > > > > > > > > > > not > > >> > > > > > > > > > > > > > > > > > > > > setting a sane default value > for > > >> max > > >> > > > direct > > >> > > > > > > > memory > > >> > > > > > > > > > and > > >> > > > > > > > > > > > > giving > > >> > > > > > > > > > > > > > > the > > >> > > > > > > > > > > > > > > > > > user > > >> > > > > > > > > > > > > > > > > > > an > > >> > > > > > > > > > > > > > > > > > > > > option to increase it if he > runs > > >> into > > >> > > an > > >> > > > > OOM. > > >> > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > @Xintong, how would > alternative > > 2 > > >> > lead > > >> > > to > > >> > > > > > lower > > >> > > > > > > > > > memory > > >> > > > > > > > > > > > > > > > utilization > > >> > > > > > > > > > > > > > > > > > than > > >> > > > > > > > > > > > > > > > > > > > > alternative 3 where we set the > > >> direct > > >> > > > > memory > > >> > > > > > > to a > > >> > > > > > > > > > > higher > > >> > > > > > > > > > > > > > value? > > >> > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > Cheers, > > >> > > > > > > > > > > > > > > > > > > > > Till > > >> > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > On Fri, Aug 9, 2019 at 9:12 AM > > >> > Xintong > > >> > > > > Song < > > >> > > > > > > > > > > > > > > > tonysong...@gmail.com > > >> > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > wrote: > > >> > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > Thanks for the feedback, > Yang. > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > Regarding your comments: > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > *Native and Direct Memory* > > >> > > > > > > > > > > > > > > > > > > > > > I think setting a very large > > max > > >> > > direct > > >> > > > > > > memory > > >> > > > > > > > > size > > >> > > > > > > > > > > > > > > definitely > > >> > > > > > > > > > > > > > > > > has > > >> > > > > > > > > > > > > > > > > > > some > > >> > > > > > > > > > > > > > > > > > > > > > good sides. E.g., we do not > > >> worry > > >> > > about > > >> > > > > > > direct > > >> > > > > > > > > OOM, > > >> > > > > > > > > > > and > > >> > > > > > > > > > > > > we > > >> > > > > > > > > > > > > > > > don't > > >> > > > > > > > > > > > > > > > > > even > > >> > > > > > > > > > > > > > > > > > > > > need > > >> > > > > > > > > > > > > > > > > > > > > > to allocate managed / > network > > >> > memory > > >> > > > with > > >> > > > > > > > > > > > > > Unsafe.allocate() . > > >> > > > > > > > > > > > > > > > > > > > > > However, there are also some > > >> down > > >> > > sides > > >> > > > > of > > >> > > > > > > > doing > > >> > > > > > > > > > > this. > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > - One thing I can think > of > > is > > >> > that > > >> > > > if > > >> > > > > a > > >> > > > > > > task > > >> > > > > > > > > > > > executor > > >> > > > > > > > > > > > > > > > > container > > >> > > > > > > > > > > > > > > > > > is > > >> > > > > > > > > > > > > > > > > > > > > > killed due to overusing > > >> memory, > > >> > it > > >> > > > > could > > >> > > > > > > be > > >> > > > > > > > > hard > > >> > > > > > > > > > > for > > >> > > > > > > > > > > > > use > > >> > > > > > > > > > > > > > > to > > >> > > > > > > > > > > > > > > > > know > > >> > > > > > > > > > > > > > > > > > > > which > > >> > > > > > > > > > > > > > > > > > > > > > part > > >> > > > > > > > > > > > > > > > > > > > > > of the memory is > overused. > > >> > > > > > > > > > > > > > > > > > > > > > - Another down side is > that > > >> the > > >> > > JVM > > >> > > > > > never > > >> > > > > > > > > > trigger > > >> > > > > > > > > > > GC > > >> > > > > > > > > > > > > due > > >> > > > > > > > > > > > > > > to > > >> > > > > > > > > > > > > > > > > > > reaching > > >> > > > > > > > > > > > > > > > > > > > > max > > >> > > > > > > > > > > > > > > > > > > > > > direct memory limit, > > because > > >> the > > >> > > > limit > > >> > > > > > is > > >> > > > > > > > too > > >> > > > > > > > > > high > > >> > > > > > > > > > > > to > > >> > > > > > > > > > > > > be > > >> > > > > > > > > > > > > > > > > > reached. > > >> > > > > > > > > > > > > > > > > > > > That > > >> > > > > > > > > > > > > > > > > > > > > > means we kind of relay on > > >> heap > > >> > > > memory > > >> > > > > to > > >> > > > > > > > > trigger > > >> > > > > > > > > > > GC > > >> > > > > > > > > > > > > and > > >> > > > > > > > > > > > > > > > > release > > >> > > > > > > > > > > > > > > > > > > > direct > > >> > > > > > > > > > > > > > > > > > > > > > memory. That could be a > > >> problem > > >> > in > > >> > > > > cases > > >> > > > > > > > where > > >> > > > > > > > > > we > > >> > > > > > > > > > > > have > > >> > > > > > > > > > > > > > > more > > >> > > > > > > > > > > > > > > > > > direct > > >> > > > > > > > > > > > > > > > > > > > > > memory > > >> > > > > > > > > > > > > > > > > > > > > > usage but not enough heap > > >> > activity > > >> > > > to > > >> > > > > > > > trigger > > >> > > > > > > > > > the > > >> > > > > > > > > > > > GC. > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > Maybe you can share your > > reasons > > >> > for > > >> > > > > > > preferring > > >> > > > > > > > > > > > setting a > > >> > > > > > > > > > > > > > > very > > >> > > > > > > > > > > > > > > > > > large > > >> > > > > > > > > > > > > > > > > > > > > value, > > >> > > > > > > > > > > > > > > > > > > > > > if there are anything else I > > >> > > > overlooked. > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > *Memory Calculation* > > >> > > > > > > > > > > > > > > > > > > > > > If there is any conflict > > between > > >> > > > multiple > > >> > > > > > > > > > > configuration > > >> > > > > > > > > > > > > > that > > >> > > > > > > > > > > > > > > > user > > >> > > > > > > > > > > > > > > > > > > > > > explicitly specified, I > think > > we > > >> > > should > > >> > > > > > throw > > >> > > > > > > > an > > >> > > > > > > > > > > error. > > >> > > > > > > > > > > > > > > > > > > > > > I think doing checking on > the > > >> > client > > >> > > > side > > >> > > > > > is > > >> > > > > > > a > > >> > > > > > > > > good > > >> > > > > > > > > > > > idea, > > >> > > > > > > > > > > > > > so > > >> > > > > > > > > > > > > > > > that > > >> > > > > > > > > > > > > > > > > > on > > >> > > > > > > > > > > > > > > > > > > > > Yarn / > > >> > > > > > > > > > > > > > > > > > > > > > K8s we can discover the > > problem > > >> > > before > > >> > > > > > > > submitting > > >> > > > > > > > > > the > > >> > > > > > > > > > > > > Flink > > >> > > > > > > > > > > > > > > > > > cluster, > > >> > > > > > > > > > > > > > > > > > > > > which > > >> > > > > > > > > > > > > > > > > > > > > > is always a good thing. > > >> > > > > > > > > > > > > > > > > > > > > > But we can not only rely on > > the > > >> > > client > > >> > > > > side > > >> > > > > > > > > > checking, > > >> > > > > > > > > > > > > > because > > >> > > > > > > > > > > > > > > > for > > >> > > > > > > > > > > > > > > > > > > > > > standalone cluster > > TaskManagers > > >> on > > >> > > > > > different > > >> > > > > > > > > > machines > > >> > > > > > > > > > > > may > > >> > > > > > > > > > > > > > > have > > >> > > > > > > > > > > > > > > > > > > > different > > >> > > > > > > > > > > > > > > > > > > > > > configurations and the > client > > >> does > > >> > > see > > >> > > > > > that. > > >> > > > > > > > > > > > > > > > > > > > > > What do you think? > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > Thank you~ > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > Xintong Song > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > On Thu, Aug 8, 2019 at 5:09 > PM > > >> Yang > > >> > > > Wang > > >> > > > > < > > >> > > > > > > > > > > > > > > > danrtsey...@gmail.com> > > >> > > > > > > > > > > > > > > > > > > > wrote: > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > Hi xintong, > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > Thanks for your detailed > > >> > proposal. > > >> > > > > After > > >> > > > > > > all > > >> > > > > > > > > the > > >> > > > > > > > > > > > memory > > >> > > > > > > > > > > > > > > > > > > configuration > > >> > > > > > > > > > > > > > > > > > > > > are > > >> > > > > > > > > > > > > > > > > > > > > > > introduced, it will be > more > > >> > > powerful > > >> > > > to > > >> > > > > > > > control > > >> > > > > > > > > > the > > >> > > > > > > > > > > > > flink > > >> > > > > > > > > > > > > > > > > memory > > >> > > > > > > > > > > > > > > > > > > > > usage. I > > >> > > > > > > > > > > > > > > > > > > > > > > just have few questions > > about > > >> it. > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > - Native and Direct > > Memory > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > We do not differentiate > user > > >> > direct > > >> > > > > > memory > > >> > > > > > > > and > > >> > > > > > > > > > > native > > >> > > > > > > > > > > > > > > memory. > > >> > > > > > > > > > > > > > > > > > They > > >> > > > > > > > > > > > > > > > > > > > are > > >> > > > > > > > > > > > > > > > > > > > > > all > > >> > > > > > > > > > > > > > > > > > > > > > > included in task off-heap > > >> memory. > > >> > > > > Right? > > >> > > > > > > So i > > >> > > > > > > > > > don’t > > >> > > > > > > > > > > > > think > > >> > > > > > > > > > > > > > > we > > >> > > > > > > > > > > > > > > > > > could > > >> > > > > > > > > > > > > > > > > > > > not > > >> > > > > > > > > > > > > > > > > > > > > > set > > >> > > > > > > > > > > > > > > > > > > > > > > the > -XX:MaxDirectMemorySize > > >> > > > properly. I > > >> > > > > > > > prefer > > >> > > > > > > > > > > > leaving > > >> > > > > > > > > > > > > > it a > > >> > > > > > > > > > > > > > > > > very > > >> > > > > > > > > > > > > > > > > > > > large > > >> > > > > > > > > > > > > > > > > > > > > > > value. > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > - Memory Calculation > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > If the sum of and > > fine-grained > > >> > > > > > > memory(network > > >> > > > > > > > > > > memory, > > >> > > > > > > > > > > > > > > managed > > >> > > > > > > > > > > > > > > > > > > memory, > > >> > > > > > > > > > > > > > > > > > > > > > etc.) > > >> > > > > > > > > > > > > > > > > > > > > > > is larger than total > process > > >> > > memory, > > >> > > > > how > > >> > > > > > do > > >> > > > > > > > we > > >> > > > > > > > > > deal > > >> > > > > > > > > > > > > with > > >> > > > > > > > > > > > > > > this > > >> > > > > > > > > > > > > > > > > > > > > situation? > > >> > > > > > > > > > > > > > > > > > > > > > Do > > >> > > > > > > > > > > > > > > > > > > > > > > we need to check the > memory > > >> > > > > configuration > > >> > > > > > > in > > >> > > > > > > > > > > client? > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > Xintong Song < > > >> > > tonysong...@gmail.com> > > >> > > > > > > > > > 于2019年8月7日周三 > > >> > > > > > > > > > > > > > > 下午10:14写道： > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > Hi everyone, > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > We would like to start a > > >> > > discussion > > >> > > > > > > thread > > >> > > > > > > > on > > >> > > > > > > > > > > > > "FLIP-49: > > >> > > > > > > > > > > > > > > > > Unified > > >> > > > > > > > > > > > > > > > > > > > > Memory > > >> > > > > > > > > > > > > > > > > > > > > > > > Configuration for > > >> > > > TaskExecutors"[1], > > >> > > > > > > where > > >> > > > > > > > we > > >> > > > > > > > > > > > > describe > > >> > > > > > > > > > > > > > > how > > >> > > > > > > > > > > > > > > > to > > >> > > > > > > > > > > > > > > > > > > > improve > > >> > > > > > > > > > > > > > > > > > > > > > > > TaskExecutor memory > > >> > > configurations. > > >> > > > > The > > >> > > > > > > > FLIP > > >> > > > > > > > > > > > document > > >> > > > > > > > > > > > > > is > > >> > > > > > > > > > > > > > > > > mostly > > >> > > > > > > > > > > > > > > > > > > > based > > >> > > > > > > > > > > > > > > > > > > > > > on > > >> > > > > > > > > > > > > > > > > > > > > > > an > > >> > > > > > > > > > > > > > > > > > > > > > > > early design "Memory > > >> Management > > >> > > and > > >> > > > > > > > > > Configuration > > >> > > > > > > > > > > > > > > > > Reloaded"[2] > > >> > > > > > > > > > > > > > > > > > by > > >> > > > > > > > > > > > > > > > > > > > > > > Stephan, > > >> > > > > > > > > > > > > > > > > > > > > > > > with updates from > > follow-up > > >> > > > > discussions > > >> > > > > > > > both > > >> > > > > > > > > > > online > > >> > > > > > > > > > > > > and > > >> > > > > > > > > > > > > > > > > > offline. > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > This FLIP addresses > > several > > >> > > > > > shortcomings > > >> > > > > > > of > > >> > > > > > > > > > > current > > >> > > > > > > > > > > > > > > (Flink > > >> > > > > > > > > > > > > > > > > 1.9) > > >> > > > > > > > > > > > > > > > > > > > > > > > TaskExecutor memory > > >> > > configuration. > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > - Different > > configuration > > >> > for > > >> > > > > > > Streaming > > >> > > > > > > > > and > > >> > > > > > > > > > > > Batch. > > >> > > > > > > > > > > > > > > > > > > > > > > > - Complex and > difficult > > >> > > > > > configuration > > >> > > > > > > of > > >> > > > > > > > > > > RocksDB > > >> > > > > > > > > > > > > in > > >> > > > > > > > > > > > > > > > > > Streaming. > > >> > > > > > > > > > > > > > > > > > > > > > > > - Complicated, > > uncertain > > >> and > > >> > > > hard > > >> > > > > to > > >> > > > > > > > > > > understand. > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > Key changes to solve the > > >> > problems > > >> > > > can > > >> > > > > > be > > >> > > > > > > > > > > summarized > > >> > > > > > > > > > > > > as > > >> > > > > > > > > > > > > > > > > follows. > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > - Extend memory > manager > > >> to > > >> > > also > > >> > > > > > > account > > >> > > > > > > > > for > > >> > > > > > > > > > > > memory > > >> > > > > > > > > > > > > > > usage > > >> > > > > > > > > > > > > > > > > by > > >> > > > > > > > > > > > > > > > > > > > state > > >> > > > > > > > > > > > > > > > > > > > > > > > backends. > > >> > > > > > > > > > > > > > > > > > > > > > > > - Modify how > > TaskExecutor > > >> > > memory > > >> > > > > is > > >> > > > > > > > > > > partitioned > > >> > > > > > > > > > > > > > > > accounted > > >> > > > > > > > > > > > > > > > > > > > > individual > > >> > > > > > > > > > > > > > > > > > > > > > > > memory reservations > and > > >> > pools. > > >> > > > > > > > > > > > > > > > > > > > > > > > - Simplify memory > > >> > > configuration > > >> > > > > > > options > > >> > > > > > > > > and > > >> > > > > > > > > > > > > > > calculations > > >> > > > > > > > > > > > > > > > > > > logics. > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > Please find more details > > in > > >> the > > >> > > > FLIP > > >> > > > > > wiki > > >> > > > > > > > > > > document > > >> > > > > > > > > > > > > [1]. > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > (Please note that the > > early > > >> > > design > > >> > > > > doc > > >> > > > > > > [2] > > >> > > > > > > > is > > >> > > > > > > > > > out > > >> > > > > > > > > > > > of > > >> > > > > > > > > > > > > > > sync, > > >> > > > > > > > > > > > > > > > > and > > >> > > > > > > > > > > > > > > > > > it > > >> > > > > > > > > > > > > > > > > > > > is > > >> > > > > > > > > > > > > > > > > > > > > > > > appreciated to have the > > >> > > discussion > > >> > > > in > > >> > > > > > > this > > >> > > > > > > > > > > mailing > > >> > > > > > > > > > > > > list > > >> > > > > > > > > > > > > > > > > > thread.) > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > Looking forward to your > > >> > > feedbacks. > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > Thank you~ > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > Xintong Song > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > [1] > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > >> > > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > >> > > > https://cwiki.apache.org/confluence/display/FLINK/FLIP-49%3A+Unified+Memory+Configuration+for+TaskExecutors > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > [2] > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > >> > > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > >> > > > https://docs.google.com/document/d/1o4KvyyXsQMGUastfPin3ZWeUXWsJgoL7piqp1fFYJvA/edit?usp=sharing > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > On Fri, Aug 16, 2019 at 2:16 PM Xintong > Song < > > >> > > > > > > > > > tonysong...@gmail.com> > > >> > > > > > > > > > > > > > wrote: > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > Thanks for sharing your opinion Till. > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > I'm also in favor of alternative 2. I was > > >> > wondering > > >> > > > > > whether > > >> > > > > > > > we > > >> > > > > > > > > > can > > >> > > > > > > > > > > > > avoid > > >> > > > > > > > > > > > > > > using Unsafe.allocate() for off-heap > managed > > >> > memory > > >> > > > and > > >> > > > > > > > network > > >> > > > > > > > > > > > memory > > >> > > > > > > > > > > > > > with > > >> > > > > > > > > > > > > > > alternative 3. But after giving it a > second > > >> > > thought, > > >> > > > I > > >> > > > > > > think > > >> > > > > > > > > even > > >> > > > > > > > > > > for > > >> > > > > > > > > > > > > > > alternative 3 using direct memory for > > off-heap > > >> > > > managed > > >> > > > > > > memory > > >> > > > > > > > > > could > > >> > > > > > > > > > > > > cause > > >> > > > > > > > > > > > > > > problems. > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > Hi Yang, > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > Regarding your concern, I think what > > proposed > > >> in > > >> > > this > > >> > > > > > FLIP > > >> > > > > > > it > > >> > > > > > > > > to > > >> > > > > > > > > > > have > > >> > > > > > > > > > > > > > both > > >> > > > > > > > > > > > > > > off-heap managed memory and network memory > > >> > > allocated > > >> > > > > > > through > > >> > > > > > > > > > > > > > > Unsafe.allocate(), which means they are > > >> > practically > > >> > > > > > native > > >> > > > > > > > > memory > > >> > > > > > > > > > > and > > >> > > > > > > > > > > > > not > > >> > > > > > > > > > > > > > > limited by JVM max direct memory. The only > > >> parts > > >> > of > > >> > > > > > memory > > >> > > > > > > > > > limited > > >> > > > > > > > > > > by > > >> > > > > > > > > > > > > JVM > > >> > > > > > > > > > > > > > > max direct memory are task off-heap memory > > and > > >> > JVM > > >> > > > > > > overhead, > > >> > > > > > > > > > which > > >> > > > > > > > > > > > are > > >> > > > > > > > > > > > > > > exactly alternative 2 suggests to set the > > JVM > > >> max > > >> > > > > direct > > >> > > > > > > > memory > > >> > > > > > > > > > to. > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > Thank you~ > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > Xintong Song > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > On Fri, Aug 16, 2019 at 1:48 PM Till > > Rohrmann > > >> < > > >> > > > > > > > > > > trohrm...@apache.org> > > >> > > > > > > > > > > > > > > wrote: > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > Thanks for the clarification Xintong. I > > >> > > understand > > >> > > > > the > > >> > > > > > > two > > >> > > > > > > > > > > > > alternatives > > >> > > > > > > > > > > > > > > > now. > > >> > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > I would be in favour of option 2 because > > it > > >> > makes > > >> > > > > > things > > >> > > > > > > > > > > explicit. > > >> > > > > > > > > > > > If > > >> > > > > > > > > > > > > > we > > >> > > > > > > > > > > > > > > > don't limit the direct memory, I fear > that > > >> we > > >> > > might > > >> > > > > end > > >> > > > > > > up > > >> > > > > > > > > in a > > >> > > > > > > > > > > > > similar > > >> > > > > > > > > > > > > > > > situation as we are currently in: The > user > > >> > might > > >> > > > see > > >> > > > > > that > > >> > > > > > > > her > > >> > > > > > > > > > > > process > > >> > > > > > > > > > > > > > > gets > > >> > > > > > > > > > > > > > > > killed by the OS and does not know why > > this > > >> is > > >> > > the > > >> > > > > > case. > > >> > > > > > > > > > > > > Consequently, > > >> > > > > > > > > > > > > > > she > > >> > > > > > > > > > > > > > > > tries to decrease the process memory > size > > >> > > (similar > > >> > > > to > > >> > > > > > > > > > increasing > > >> > > > > > > > > > > > the > > >> > > > > > > > > > > > > > > cutoff > > >> > > > > > > > > > > > > > > > ratio) in order to accommodate for the > > extra > > >> > > direct > > >> > > > > > > memory. > > >> > > > > > > > > > Even > > >> > > > > > > > > > > > > worse, > > >> > > > > > > > > > > > > > > she > > >> > > > > > > > > > > > > > > > tries to decrease memory budgets which > are > > >> not > > >> > > > fully > > >> > > > > > used > > >> > > > > > > > and > > >> > > > > > > > > > > hence > > >> > > > > > > > > > > > > > won't > > >> > > > > > > > > > > > > > > > change the overall memory consumption. > > >> > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > Cheers, > > >> > > > > > > > > > > > > > > > Till > > >> > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > On Fri, Aug 16, 2019 at 11:01 AM Xintong > > >> Song < > > >> > > > > > > > > > > > tonysong...@gmail.com > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > wrote: > > >> > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > Let me explain this with a concrete > > >> example > > >> > > Till. > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > Let's say we have the following > > scenario. > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > Total Process Memory: 1GB > > >> > > > > > > > > > > > > > > > > JVM Direct Memory (Task Off-Heap > Memory > > + > > >> JVM > > >> > > > > > > Overhead): > > >> > > > > > > > > > 200MB > > >> > > > > > > > > > > > > > > > > Other Memory (JVM Heap Memory, JVM > > >> Metaspace, > > >> > > > > > Off-Heap > > >> > > > > > > > > > Managed > > >> > > > > > > > > > > > > Memory > > >> > > > > > > > > > > > > > > and > > >> > > > > > > > > > > > > > > > > Network Memory): 800MB > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > For alternative 2, we set > > >> > > -XX:MaxDirectMemorySize > > >> > > > > to > > >> > > > > > > > 200MB. > > >> > > > > > > > > > > > > > > > > For alternative 3, we set > > >> > > -XX:MaxDirectMemorySize > > >> > > > > to > > >> > > > > > a > > >> > > > > > > > very > > >> > > > > > > > > > > large > > >> > > > > > > > > > > > > > > value, > > >> > > > > > > > > > > > > > > > > let's say 1TB. > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > If the actual direct memory usage of > > Task > > >> > > > Off-Heap > > >> > > > > > > Memory > > >> > > > > > > > > and > > >> > > > > > > > > > > JVM > > >> > > > > > > > > > > > > > > > Overhead > > >> > > > > > > > > > > > > > > > > do not exceed 200MB, then alternative > 2 > > >> and > > >> > > > > > > alternative 3 > > >> > > > > > > > > > > should > > >> > > > > > > > > > > > > have > > >> > > > > > > > > > > > > > > the > > >> > > > > > > > > > > > > > > > > same utility. Setting larger > > >> > > > > -XX:MaxDirectMemorySize > > >> > > > > > > will > > >> > > > > > > > > not > > >> > > > > > > > > > > > > reduce > > >> > > > > > > > > > > > > > > the > > >> > > > > > > > > > > > > > > > > sizes of the other memory pools. > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > If the actual direct memory usage of > > Task > > >> > > > Off-Heap > > >> > > > > > > Memory > > >> > > > > > > > > and > > >> > > > > > > > > > > JVM > > >> > > > > > > > > > > > > > > > > Overhead potentially exceed 200MB, > then > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > - Alternative 2 suffers from > frequent > > >> OOM. > > >> > > To > > >> > > > > > avoid > > >> > > > > > > > > that, > > >> > > > > > > > > > > the > > >> > > > > > > > > > > > > only > > >> > > > > > > > > > > > > > > > thing > > >> > > > > > > > > > > > > > > > > user can do is to modify the > > >> configuration > > >> > > and > > >> > > > > > > > increase > > >> > > > > > > > > > JVM > > >> > > > > > > > > > > > > Direct > > >> > > > > > > > > > > > > > > > > Memory > > >> > > > > > > > > > > > > > > > > (Task Off-Heap Memory + JVM > > Overhead). > > >> > Let's > > >> > > > say > > >> > > > > > > that > > >> > > > > > > > > user > > >> > > > > > > > > > > > > > increases > > >> > > > > > > > > > > > > > > > JVM > > >> > > > > > > > > > > > > > > > > Direct Memory to 250MB, this will > > >> reduce > > >> > the > > >> > > > > total > > >> > > > > > > > size > > >> > > > > > > > > of > > >> > > > > > > > > > > > other > > >> > > > > > > > > > > > > > > > memory > > >> > > > > > > > > > > > > > > > > pools to 750MB, given the total > > process > > >> > > memory > > >> > > > > > > remains > > >> > > > > > > > > > 1GB. > > >> > > > > > > > > > > > > > > > > - For alternative 3, there is no > > >> chance of > > >> > > > > direct > > >> > > > > > > OOM. > > >> > > > > > > > > > There > > >> > > > > > > > > > > > are > > >> > > > > > > > > > > > > > > > chances > > >> > > > > > > > > > > > > > > > > of exceeding the total process > memory > > >> > limit, > > >> > > > but > > >> > > > > > > given > > >> > > > > > > > > > that > > >> > > > > > > > > > > > the > > >> > > > > > > > > > > > > > > > process > > >> > > > > > > > > > > > > > > > > may > > >> > > > > > > > > > > > > > > > > not use up all the reserved native > > >> memory > > >> > > > > > (Off-Heap > > >> > > > > > > > > > Managed > > >> > > > > > > > > > > > > > Memory, > > >> > > > > > > > > > > > > > > > > Network > > >> > > > > > > > > > > > > > > > > Memory, JVM Metaspace), if the > actual > > >> > direct > > >> > > > > > memory > > >> > > > > > > > > usage > > >> > > > > > > > > > is > > >> > > > > > > > > > > > > > > slightly > > >> > > > > > > > > > > > > > > > > above > > >> > > > > > > > > > > > > > > > > yet very close to 200MB, user > > probably > > >> do > > >> > > not > > >> > > > > need > > >> > > > > > > to > > >> > > > > > > > > > change > > >> > > > > > > > > > > > the > > >> > > > > > > > > > > > > > > > > configurations. > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > Therefore, I think from the user's > > >> > > perspective, a > > >> > > > > > > > feasible > > >> > > > > > > > > > > > > > > configuration > > >> > > > > > > > > > > > > > > > > for alternative 2 may lead to lower > > >> resource > > >> > > > > > > utilization > > >> > > > > > > > > > > compared > > >> > > > > > > > > > > > > to > > >> > > > > > > > > > > > > > > > > alternative 3. > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > Thank you~ > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > Xintong Song > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > On Fri, Aug 16, 2019 at 10:28 AM Till > > >> > Rohrmann > > >> > > < > > >> > > > > > > > > > > > > trohrm...@apache.org > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > wrote: > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > I guess you have to help me > understand > > >> the > > >> > > > > > difference > > >> > > > > > > > > > between > > >> > > > > > > > > > > > > > > > > alternative 2 > > >> > > > > > > > > > > > > > > > > > and 3 wrt to memory under > utilization > > >> > > Xintong. > > >> > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > - Alternative 2: set > > >> XX:MaxDirectMemorySize > > >> > > to > > >> > > > > Task > > >> > > > > > > > > > Off-Heap > > >> > > > > > > > > > > > > Memory > > >> > > > > > > > > > > > > > > and > > >> > > > > > > > > > > > > > > > > JVM > > >> > > > > > > > > > > > > > > > > > Overhead. Then there is the risk > that > > >> this > > >> > > size > > >> > > > > is > > >> > > > > > > too > > >> > > > > > > > > low > > >> > > > > > > > > > > > > > resulting > > >> > > > > > > > > > > > > > > > in a > > >> > > > > > > > > > > > > > > > > > lot of garbage collection and > > >> potentially > > >> > an > > >> > > > OOM. > > >> > > > > > > > > > > > > > > > > > - Alternative 3: set > > >> XX:MaxDirectMemorySize > > >> > > to > > >> > > > > > > > something > > >> > > > > > > > > > > larger > > >> > > > > > > > > > > > > > than > > >> > > > > > > > > > > > > > > > > > alternative 2. This would of course > > >> reduce > > >> > > the > > >> > > > > > sizes > > >> > > > > > > of > > >> > > > > > > > > the > > >> > > > > > > > > > > > other > > >> > > > > > > > > > > > > > > > memory > > >> > > > > > > > > > > > > > > > > > types. > > >> > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > How would alternative 2 now result > in > > an > > >> > > under > > >> > > > > > > > > utilization > > >> > > > > > > > > > of > > >> > > > > > > > > > > > > > memory > > >> > > > > > > > > > > > > > > > > > compared to alternative 3? If > > >> alternative 3 > > >> > > > > > strictly > > >> > > > > > > > > sets a > > >> > > > > > > > > > > > > higher > > >> > > > > > > > > > > > > > > max > > >> > > > > > > > > > > > > > > > > > direct memory size and we use only > > >> little, > > >> > > > then I > > >> > > > > > > would > > >> > > > > > > > > > > expect > > >> > > > > > > > > > > > > that > > >> > > > > > > > > > > > > > > > > > alternative 3 results in memory > under > > >> > > > > utilization. > > >> > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > Cheers, > > >> > > > > > > > > > > > > > > > > > Till > > >> > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > On Tue, Aug 13, 2019 at 4:19 PM Yang > > >> Wang < > > >> > > > > > > > > > > > danrtsey...@gmail.com > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > wrote: > > >> > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > Hi xintong,till > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > Native and Direct Memory > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > My point is setting a very large > max > > >> > direct > > >> > > > > > memory > > >> > > > > > > > size > > >> > > > > > > > > > > when > > >> > > > > > > > > > > > we > > >> > > > > > > > > > > > > > do > > >> > > > > > > > > > > > > > > > not > > >> > > > > > > > > > > > > > > > > > > differentiate direct and native > > >> memory. > > >> > If > > >> > > > the > > >> > > > > > > direct > > >> > > > > > > > > > > > > > > > memory,including > > >> > > > > > > > > > > > > > > > > > user > > >> > > > > > > > > > > > > > > > > > > direct memory and framework direct > > >> > > > memory,could > > >> > > > > > be > > >> > > > > > > > > > > calculated > > >> > > > > > > > > > > > > > > > > > > correctly,then > > >> > > > > > > > > > > > > > > > > > > i am in favor of setting direct > > memory > > >> > with > > >> > > > > fixed > > >> > > > > > > > > value. > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > Memory Calculation > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > I agree with xintong. For Yarn and > > >> k8s,we > > >> > > > need > > >> > > > > to > > >> > > > > > > > check > > >> > > > > > > > > > the > > >> > > > > > > > > > > > > > memory > > >> > > > > > > > > > > > > > > > > > > configurations in client to avoid > > >> > > submitting > > >> > > > > > > > > successfully > > >> > > > > > > > > > > and > > >> > > > > > > > > > > > > > > failing > > >> > > > > > > > > > > > > > > > > in > > >> > > > > > > > > > > > > > > > > > > the flink master. > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > Best, > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > Yang > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > Xintong Song < > tonysong...@gmail.com > > >> > > > > >于2019年8月13日 > > >> > > > > > > > > > 周二22:07写道： > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > Thanks for replying, Till. > > >> > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > About MemorySegment, I think you > > are > > >> > > right > > >> > > > > that > > >> > > > > > > we > > >> > > > > > > > > > should > > >> > > > > > > > > > > > not > > >> > > > > > > > > > > > > > > > include > > >> > > > > > > > > > > > > > > > > > > this > > >> > > > > > > > > > > > > > > > > > > > issue in the scope of this FLIP. > > >> This > > >> > > FLIP > > >> > > > > > should > > >> > > > > > > > > > > > concentrate > > >> > > > > > > > > > > > > > on > > >> > > > > > > > > > > > > > > > how > > >> > > > > > > > > > > > > > > > > to > > >> > > > > > > > > > > > > > > > > > > > configure memory pools for > > >> > TaskExecutors, > > >> > > > > with > > >> > > > > > > > > minimum > > >> > > > > > > > > > > > > > > involvement > > >> > > > > > > > > > > > > > > > on > > >> > > > > > > > > > > > > > > > > > how > > >> > > > > > > > > > > > > > > > > > > > memory consumers use it. > > >> > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > About direct memory, I think > > >> > alternative > > >> > > 3 > > >> > > > > may > > >> > > > > > > not > > >> > > > > > > > > > having > > >> > > > > > > > > > > > the > > >> > > > > > > > > > > > > > > same > > >> > > > > > > > > > > > > > > > > over > > >> > > > > > > > > > > > > > > > > > > > reservation issue that > > alternative 2 > > >> > > does, > > >> > > > > but > > >> > > > > > at > > >> > > > > > > > the > > >> > > > > > > > > > > cost > > >> > > > > > > > > > > > of > > >> > > > > > > > > > > > > > > risk > > >> > > > > > > > > > > > > > > > of > > >> > > > > > > > > > > > > > > > > > > over > > >> > > > > > > > > > > > > > > > > > > > using memory at the container > > level, > > >> > > which > > >> > > > is > > >> > > > > > not > > >> > > > > > > > > good. > > >> > > > > > > > > > > My > > >> > > > > > > > > > > > > > point > > >> > > > > > > > > > > > > > > is > > >> > > > > > > > > > > > > > > > > > that > > >> > > > > > > > > > > > > > > > > > > > both "Task Off-Heap Memory" and > > "JVM > > >> > > > > Overhead" > > >> > > > > > > are > > >> > > > > > > > > not > > >> > > > > > > > > > > easy > > >> > > > > > > > > > > > > to > > >> > > > > > > > > > > > > > > > > config. > > >> > > > > > > > > > > > > > > > > > > For > > >> > > > > > > > > > > > > > > > > > > > alternative 2, users might > > configure > > >> > them > > >> > > > > > higher > > >> > > > > > > > than > > >> > > > > > > > > > > what > > >> > > > > > > > > > > > > > > actually > > >> > > > > > > > > > > > > > > > > > > needed, > > >> > > > > > > > > > > > > > > > > > > > just to avoid getting a direct > > OOM. > > >> For > > >> > > > > > > alternative > > >> > > > > > > > > 3, > > >> > > > > > > > > > > > users > > >> > > > > > > > > > > > > do > > >> > > > > > > > > > > > > > > not > > >> > > > > > > > > > > > > > > > > get > > >> > > > > > > > > > > > > > > > > > > > direct OOM, so they may not > config > > >> the > > >> > > two > > >> > > > > > > options > > >> > > > > > > > > > > > > aggressively > > >> > > > > > > > > > > > > > > > high. > > >> > > > > > > > > > > > > > > > > > But > > >> > > > > > > > > > > > > > > > > > > > the consequences are risks of > > >> overall > > >> > > > > container > > >> > > > > > > > > memory > > >> > > > > > > > > > > > usage > > >> > > > > > > > > > > > > > > > exceeds > > >> > > > > > > > > > > > > > > > > > the > > >> > > > > > > > > > > > > > > > > > > > budget. > > >> > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > Thank you~ > > >> > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > Xintong Song > > >> > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > On Tue, Aug 13, 2019 at 9:39 AM > > Till > > >> > > > > Rohrmann < > > >> > > > > > > > > > > > > > > > trohrm...@apache.org> > > >> > > > > > > > > > > > > > > > > > > > wrote: > > >> > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > Thanks for proposing this FLIP > > >> > Xintong. > > >> > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > All in all I think it already > > >> looks > > >> > > quite > > >> > > > > > good. > > >> > > > > > > > > > > > Concerning > > >> > > > > > > > > > > > > > the > > >> > > > > > > > > > > > > > > > > first > > >> > > > > > > > > > > > > > > > > > > open > > >> > > > > > > > > > > > > > > > > > > > > question about allocating > memory > > >> > > > segments, > > >> > > > > I > > >> > > > > > > was > > >> > > > > > > > > > > > wondering > > >> > > > > > > > > > > > > > > > whether > > >> > > > > > > > > > > > > > > > > > this > > >> > > > > > > > > > > > > > > > > > > > is > > >> > > > > > > > > > > > > > > > > > > > > strictly necessary to do in > the > > >> > context > > >> > > > of > > >> > > > > > this > > >> > > > > > > > > FLIP > > >> > > > > > > > > > or > > >> > > > > > > > > > > > > > whether > > >> > > > > > > > > > > > > > > > > this > > >> > > > > > > > > > > > > > > > > > > > could > > >> > > > > > > > > > > > > > > > > > > > > be done as a follow up? > Without > > >> > knowing > > >> > > > all > > >> > > > > > > > > details, > > >> > > > > > > > > > I > > >> > > > > > > > > > > > > would > > >> > > > > > > > > > > > > > be > > >> > > > > > > > > > > > > > > > > > > concerned > > >> > > > > > > > > > > > > > > > > > > > > that we would widen the scope > of > > >> this > > >> > > > FLIP > > >> > > > > > too > > >> > > > > > > > much > > >> > > > > > > > > > > > because > > >> > > > > > > > > > > > > > we > > >> > > > > > > > > > > > > > > > > would > > >> > > > > > > > > > > > > > > > > > > have > > >> > > > > > > > > > > > > > > > > > > > > to touch all the existing call > > >> sites > > >> > of > > >> > > > the > > >> > > > > > > > > > > MemoryManager > > >> > > > > > > > > > > > > > where > > >> > > > > > > > > > > > > > > > we > > >> > > > > > > > > > > > > > > > > > > > allocate > > >> > > > > > > > > > > > > > > > > > > > > memory segments (this should > > >> mainly > > >> > be > > >> > > > > batch > > >> > > > > > > > > > > operators). > > >> > > > > > > > > > > > > The > > >> > > > > > > > > > > > > > > > > addition > > >> > > > > > > > > > > > > > > > > > > of > > >> > > > > > > > > > > > > > > > > > > > > the memory reservation call to > > the > > >> > > > > > > MemoryManager > > >> > > > > > > > > > should > > >> > > > > > > > > > > > not > > >> > > > > > > > > > > > > > be > > >> > > > > > > > > > > > > > > > > > affected > > >> > > > > > > > > > > > > > > > > > > > by > > >> > > > > > > > > > > > > > > > > > > > > this and I would hope that > this > > is > > >> > the > > >> > > > only > > >> > > > > > > point > > >> > > > > > > > > of > > >> > > > > > > > > > > > > > > interaction > > >> > > > > > > > > > > > > > > > a > > >> > > > > > > > > > > > > > > > > > > > > streaming job would have with > > the > > >> > > > > > > MemoryManager. > > >> > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > Concerning the second open > > >> question > > >> > > about > > >> > > > > > > setting > > >> > > > > > > > > or > > >> > > > > > > > > > > not > > >> > > > > > > > > > > > > > > setting > > >> > > > > > > > > > > > > > > > a > > >> > > > > > > > > > > > > > > > > > max > > >> > > > > > > > > > > > > > > > > > > > > direct memory limit, I would > > also > > >> be > > >> > > > > > interested > > >> > > > > > > > why > > >> > > > > > > > > > > Yang > > >> > > > > > > > > > > > > Wang > > >> > > > > > > > > > > > > > > > > thinks > > >> > > > > > > > > > > > > > > > > > > > > leaving it open would be best. > > My > > >> > > concern > > >> > > > > > about > > >> > > > > > > > > this > > >> > > > > > > > > > > > would > > >> > > > > > > > > > > > > be > > >> > > > > > > > > > > > > > > > that > > >> > > > > > > > > > > > > > > > > we > > >> > > > > > > > > > > > > > > > > > > > would > > >> > > > > > > > > > > > > > > > > > > > > be in a similar situation as > we > > >> are > > >> > now > > >> > > > > with > > >> > > > > > > the > > >> > > > > > > > > > > > > > > > > RocksDBStateBackend. > > >> > > > > > > > > > > > > > > > > > > If > > >> > > > > > > > > > > > > > > > > > > > > the different memory pools are > > not > > >> > > > clearly > > >> > > > > > > > > separated > > >> > > > > > > > > > > and > > >> > > > > > > > > > > > > can > > >> > > > > > > > > > > > > > > > spill > > >> > > > > > > > > > > > > > > > > > over > > >> > > > > > > > > > > > > > > > > > > > to > > >> > > > > > > > > > > > > > > > > > > > > a different pool, then it is > > quite > > >> > hard > > >> > > > to > > >> > > > > > > > > understand > > >> > > > > > > > > > > > what > > >> > > > > > > > > > > > > > > > exactly > > >> > > > > > > > > > > > > > > > > > > > causes a > > >> > > > > > > > > > > > > > > > > > > > > process to get killed for > using > > >> too > > >> > > much > > >> > > > > > > memory. > > >> > > > > > > > > This > > >> > > > > > > > > > > > could > > >> > > > > > > > > > > > > > > then > > >> > > > > > > > > > > > > > > > > > easily > > >> > > > > > > > > > > > > > > > > > > > > lead to a similar situation > what > > >> we > > >> > > have > > >> > > > > with > > >> > > > > > > the > > >> > > > > > > > > > > > > > cutoff-ratio. > > >> > > > > > > > > > > > > > > > So > > >> > > > > > > > > > > > > > > > > > why > > >> > > > > > > > > > > > > > > > > > > > not > > >> > > > > > > > > > > > > > > > > > > > > setting a sane default value > for > > >> max > > >> > > > direct > > >> > > > > > > > memory > > >> > > > > > > > > > and > > >> > > > > > > > > > > > > giving > > >> > > > > > > > > > > > > > > the > > >> > > > > > > > > > > > > > > > > > user > > >> > > > > > > > > > > > > > > > > > > an > > >> > > > > > > > > > > > > > > > > > > > > option to increase it if he > runs > > >> into > > >> > > an > > >> > > > > OOM. > > >> > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > @Xintong, how would > alternative > > 2 > > >> > lead > > >> > > to > > >> > > > > > lower > > >> > > > > > > > > > memory > > >> > > > > > > > > > > > > > > > utilization > > >> > > > > > > > > > > > > > > > > > than > > >> > > > > > > > > > > > > > > > > > > > > alternative 3 where we set the > > >> direct > > >> > > > > memory > > >> > > > > > > to a > > >> > > > > > > > > > > higher > > >> > > > > > > > > > > > > > value? > > >> > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > Cheers, > > >> > > > > > > > > > > > > > > > > > > > > Till > > >> > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > On Fri, Aug 9, 2019 at 9:12 AM > > >> > Xintong > > >> > > > > Song < > > >> > > > > > > > > > > > > > > > tonysong...@gmail.com > > >> > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > wrote: > > >> > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > Thanks for the feedback, > Yang. > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > Regarding your comments: > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > *Native and Direct Memory* > > >> > > > > > > > > > > > > > > > > > > > > > I think setting a very large > > max > > >> > > direct > > >> > > > > > > memory > > >> > > > > > > > > size > > >> > > > > > > > > > > > > > > definitely > > >> > > > > > > > > > > > > > > > > has > > >> > > > > > > > > > > > > > > > > > > some > > >> > > > > > > > > > > > > > > > > > > > > > good sides. E.g., we do not > > >> worry > > >> > > about > > >> > > > > > > direct > > >> > > > > > > > > OOM, > > >> > > > > > > > > > > and > > >> > > > > > > > > > > > > we > > >> > > > > > > > > > > > > > > > don't > > >> > > > > > > > > > > > > > > > > > even > > >> > > > > > > > > > > > > > > > > > > > > need > > >> > > > > > > > > > > > > > > > > > > > > > to allocate managed / > network > > >> > memory > > >> > > > with > > >> > > > > > > > > > > > > > Unsafe.allocate() . > > >> > > > > > > > > > > > > > > > > > > > > > However, there are also some > > >> down > > >> > > sides > > >> > > > > of > > >> > > > > > > > doing > > >> > > > > > > > > > > this. > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > - One thing I can think > of > > is > > >> > that > > >> > > > if > > >> > > > > a > > >> > > > > > > task > > >> > > > > > > > > > > > executor > > >> > > > > > > > > > > > > > > > > container > > >> > > > > > > > > > > > > > > > > > is > > >> > > > > > > > > > > > > > > > > > > > > > killed due to overusing > > >> memory, > > >> > it > > >> > > > > could > > >> > > > > > > be > > >> > > > > > > > > hard > > >> > > > > > > > > > > for > > >> > > > > > > > > > > > > use > > >> > > > > > > > > > > > > > > to > > >> > > > > > > > > > > > > > > > > know > > >> > > > > > > > > > > > > > > > > > > > which > > >> > > > > > > > > > > > > > > > > > > > > > part > > >> > > > > > > > > > > > > > > > > > > > > > of the memory is > overused. > > >> > > > > > > > > > > > > > > > > > > > > > - Another down side is > that > > >> the > > >> > > JVM > > >> > > > > > never > > >> > > > > > > > > > trigger > > >> > > > > > > > > > > GC > > >> > > > > > > > > > > > > due > > >> > > > > > > > > > > > > > > to > > >> > > > > > > > > > > > > > > > > > > reaching > > >> > > > > > > > > > > > > > > > > > > > > max > > >> > > > > > > > > > > > > > > > > > > > > > direct memory limit, > > because > > >> the > > >> > > > limit > > >> > > > > > is > > >> > > > > > > > too > > >> > > > > > > > > > high > > >> > > > > > > > > > > > to > > >> > > > > > > > > > > > > be > > >> > > > > > > > > > > > > > > > > > reached. > > >> > > > > > > > > > > > > > > > > > > > That > > >> > > > > > > > > > > > > > > > > > > > > > means we kind of relay on > > >> heap > > >> > > > memory > > >> > > > > to > > >> > > > > > > > > trigger > > >> > > > > > > > > > > GC > > >> > > > > > > > > > > > > and > > >> > > > > > > > > > > > > > > > > release > > >> > > > > > > > > > > > > > > > > > > > direct > > >> > > > > > > > > > > > > > > > > > > > > > memory. That could be a > > >> problem > > >> > in > > >> > > > > cases > > >> > > > > > > > where > > >> > > > > > > > > > we > > >> > > > > > > > > > > > have > > >> > > > > > > > > > > > > > > more > > >> > > > > > > > > > > > > > > > > > direct > > >> > > > > > > > > > > > > > > > > > > > > > memory > > >> > > > > > > > > > > > > > > > > > > > > > usage but not enough heap > > >> > activity > > >> > > > to > > >> > > > > > > > trigger > > >> > > > > > > > > > the > > >> > > > > > > > > > > > GC. > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > Maybe you can share your > > reasons > > >> > for > > >> > > > > > > preferring > > >> > > > > > > > > > > > setting a > > >> > > > > > > > > > > > > > > very > > >> > > > > > > > > > > > > > > > > > large > > >> > > > > > > > > > > > > > > > > > > > > value, > > >> > > > > > > > > > > > > > > > > > > > > > if there are anything else I > > >> > > > overlooked. > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > *Memory Calculation* > > >> > > > > > > > > > > > > > > > > > > > > > If there is any conflict > > between > > >> > > > multiple > > >> > > > > > > > > > > configuration > > >> > > > > > > > > > > > > > that > > >> > > > > > > > > > > > > > > > user > > >> > > > > > > > > > > > > > > > > > > > > > explicitly specified, I > think > > we > > >> > > should > > >> > > > > > throw > > >> > > > > > > > an > > >> > > > > > > > > > > error. > > >> > > > > > > > > > > > > > > > > > > > > > I think doing checking on > the > > >> > client > > >> > > > side > > >> > > > > > is > > >> > > > > > > a > > >> > > > > > > > > good > > >> > > > > > > > > > > > idea, > > >> > > > > > > > > > > > > > so > > >> > > > > > > > > > > > > > > > that > > >> > > > > > > > > > > > > > > > > > on > > >> > > > > > > > > > > > > > > > > > > > > Yarn / > > >> > > > > > > > > > > > > > > > > > > > > > K8s we can discover the > > problem > > >> > > before > > >> > > > > > > > submitting > > >> > > > > > > > > > the > > >> > > > > > > > > > > > > Flink > > >> > > > > > > > > > > > > > > > > > cluster, > > >> > > > > > > > > > > > > > > > > > > > > which > > >> > > > > > > > > > > > > > > > > > > > > > is always a good thing. > > >> > > > > > > > > > > > > > > > > > > > > > But we can not only rely on > > the > > >> > > client > > >> > > > > side > > >> > > > > > > > > > checking, > > >> > > > > > > > > > > > > > because > > >> > > > > > > > > > > > > > > > for > > >> > > > > > > > > > > > > > > > > > > > > > standalone cluster > > TaskManagers > > >> on > > >> > > > > > different > > >> > > > > > > > > > machines > > >> > > > > > > > > > > > may > > >> > > > > > > > > > > > > > > have > > >> > > > > > > > > > > > > > > > > > > > different > > >> > > > > > > > > > > > > > > > > > > > > > configurations and the > client > > >> does > > >> > > see > > >> > > > > > that. > > >> > > > > > > > > > > > > > > > > > > > > > What do you think? > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > Thank you~ > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > Xintong Song > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > On Thu, Aug 8, 2019 at 5:09 > PM > > >> Yang > > >> > > > Wang > > >> > > > > < > > >> > > > > > > > > > > > > > > > danrtsey...@gmail.com> > > >> > > > > > > > > > > > > > > > > > > > wrote: > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > Hi xintong, > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > Thanks for your detailed > > >> > proposal. > > >> > > > > After > > >> > > > > > > all > > >> > > > > > > > > the > > >> > > > > > > > > > > > memory > > >> > > > > > > > > > > > > > > > > > > configuration > > >> > > > > > > > > > > > > > > > > > > > > are > > >> > > > > > > > > > > > > > > > > > > > > > > introduced, it will be > more > > >> > > powerful > > >> > > > to > > >> > > > > > > > control > > >> > > > > > > > > > the > > >> > > > > > > > > > > > > flink > > >> > > > > > > > > > > > > > > > > memory > > >> > > > > > > > > > > > > > > > > > > > > usage. I > > >> > > > > > > > > > > > > > > > > > > > > > > just have few questions > > about > > >> it. > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > - Native and Direct > > Memory > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > We do not differentiate > user > > >> > direct > > >> > > > > > memory > > >> > > > > > > > and > > >> > > > > > > > > > > native > > >> > > > > > > > > > > > > > > memory. > > >> > > > > > > > > > > > > > > > > > They > > >> > > > > > > > > > > > > > > > > > > > are > > >> > > > > > > > > > > > > > > > > > > > > > all > > >> > > > > > > > > > > > > > > > > > > > > > > included in task off-heap > > >> memory. > > >> > > > > Right? > > >> > > > > > > So i > > >> > > > > > > > > > don’t > > >> > > > > > > > > > > > > think > > >> > > > > > > > > > > > > > > we > > >> > > > > > > > > > > > > > > > > > could > > >> > > > > > > > > > > > > > > > > > > > not > > >> > > > > > > > > > > > > > > > > > > > > > set > > >> > > > > > > > > > > > > > > > > > > > > > > the > -XX:MaxDirectMemorySize > > >> > > > properly. I > > >> > > > > > > > prefer > > >> > > > > > > > > > > > leaving > > >> > > > > > > > > > > > > > it a > > >> > > > > > > > > > > > > > > > > very > > >> > > > > > > > > > > > > > > > > > > > large > > >> > > > > > > > > > > > > > > > > > > > > > > value. > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > - Memory Calculation > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > If the sum of and > > fine-grained > > >> > > > > > > memory(network > > >> > > > > > > > > > > memory, > > >> > > > > > > > > > > > > > > managed > > >> > > > > > > > > > > > > > > > > > > memory, > > >> > > > > > > > > > > > > > > > > > > > > > etc.) > > >> > > > > > > > > > > > > > > > > > > > > > > is larger than total > process > > >> > > memory, > > >> > > > > how > > >> > > > > > do > > >> > > > > > > > we > > >> > > > > > > > > > deal > > >> > > > > > > > > > > > > with > > >> > > > > > > > > > > > > > > this > > >> > > > > > > > > > > > > > > > > > > > > situation? > > >> > > > > > > > > > > > > > > > > > > > > > Do > > >> > > > > > > > > > > > > > > > > > > > > > > we need to check the > memory > > >> > > > > configuration > > >> > > > > > > in > > >> > > > > > > > > > > client? > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > Xintong Song < > > >> > > tonysong...@gmail.com> > > >> > > > > > > > > > 于2019年8月7日周三 > > >> > > > > > > > > > > > > > > 下午10:14写道： > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > Hi everyone, > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > We would like to start a > > >> > > discussion > > >> > > > > > > thread > > >> > > > > > > > on > > >> > > > > > > > > > > > > "FLIP-49: > > >> > > > > > > > > > > > > > > > > Unified > > >> > > > > > > > > > > > > > > > > > > > > Memory > > >> > > > > > > > > > > > > > > > > > > > > > > > Configuration for > > >> > > > TaskExecutors"[1], > > >> > > > > > > where > > >> > > > > > > > we > > >> > > > > > > > > > > > > describe > > >> > > > > > > > > > > > > > > how > > >> > > > > > > > > > > > > > > > to > > >> > > > > > > > > > > > > > > > > > > > improve > > >> > > > > > > > > > > > > > > > > > > > > > > > TaskExecutor memory > > >> > > configurations. > > >> > > > > The > > >> > > > > > > > FLIP > > >> > > > > > > > > > > > document > > >> > > > > > > > > > > > > > is > > >> > > > > > > > > > > > > > > > > mostly > > >> > > > > > > > > > > > > > > > > > > > based > > >> > > > > > > > > > > > > > > > > > > > > > on > > >> > > > > > > > > > > > > > > > > > > > > > > an > > >> > > > > > > > > > > > > > > > > > > > > > > > early design "Memory > > >> Management > > >> > > and > > >> > > > > > > > > > Configuration > > >> > > > > > > > > > > > > > > > > Reloaded"[2] > > >> > > > > > > > > > > > > > > > > > by > > >> > > > > > > > > > > > > > > > > > > > > > > Stephan, > > >> > > > > > > > > > > > > > > > > > > > > > > > with updates from > > follow-up > > >> > > > > discussions > > >> > > > > > > > both > > >> > > > > > > > > > > online > > >> > > > > > > > > > > > > and > > >> > > > > > > > > > > > > > > > > > offline. > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > This FLIP addresses > > several > > >> > > > > > shortcomings > > >> > > > > > > of > > >> > > > > > > > > > > current > > >> > > > > > > > > > > > > > > (Flink > > >> > > > > > > > > > > > > > > > > 1.9) > > >> > > > > > > > > > > > > > > > > > > > > > > > TaskExecutor memory > > >> > > configuration. > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > - Different > > configuration > > >> > for > > >> > > > > > > Streaming > > >> > > > > > > > > and > > >> > > > > > > > > > > > Batch. > > >> > > > > > > > > > > > > > > > > > > > > > > > - Complex and > difficult > > >> > > > > > configuration > > >> > > > > > > of > > >> > > > > > > > > > > RocksDB > > >> > > > > > > > > > > > > in > > >> > > > > > > > > > > > > > > > > > Streaming. > > >> > > > > > > > > > > > > > > > > > > > > > > > - Complicated, > > uncertain > > >> and > > >> > > > hard > > >> > > > > to > > >> > > > > > > > > > > understand. > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > Key changes to solve the > > >> > problems > > >> > > > can > > >> > > > > > be > > >> > > > > > > > > > > summarized > > >> > > > > > > > > > > > > as > > >> > > > > > > > > > > > > > > > > follows. > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > - Extend memory > manager > > >> to > > >> > > also > > >> > > > > > > account > > >> > > > > > > > > for > > >> > > > > > > > > > > > memory > > >> > > > > > > > > > > > > > > usage > > >> > > > > > > > > > > > > > > > > by > > >> > > > > > > > > > > > > > > > > > > > state > > >> > > > > > > > > > > > > > > > > > > > > > > > backends. > > >> > > > > > > > > > > > > > > > > > > > > > > > - Modify how > > TaskExecutor > > >> > > memory > > >> > > > > is > > >> > > > > > > > > > > partitioned > > >> > > > > > > > > > > > > > > > accounted > > >> > > > > > > > > > > > > > > > > > > > > individual > > >> > > > > > > > > > > > > > > > > > > > > > > > memory reservations > and > > >> > pools. > > >> > > > > > > > > > > > > > > > > > > > > > > > - Simplify memory > > >> > > configuration > > >> > > > > > > options > > >> > > > > > > > > and > > >> > > > > > > > > > > > > > > calculations > > >> > > > > > > > > > > > > > > > > > > logics. > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > Please find more details > > in > > >> the > > >> > > > FLIP > > >> > > > > > wiki > > >> > > > > > > > > > > document > > >> > > > > > > > > > > > > [1]. > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > (Please note that the > > early > > >> > > design > > >> > > > > doc > > >> > > > > > > [2] > > >> > > > > > > > is > > >> > > > > > > > > > out > > >> > > > > > > > > > > > of > > >> > > > > > > > > > > > > > > sync, > > >> > > > > > > > > > > > > > > > > and > > >> > > > > > > > > > > > > > > > > > it > > >> > > > > > > > > > > > > > > > > > > > is > > >> > > > > > > > > > > > > > > > > > > > > > > > appreciated to have the > > >> > > discussion > > >> > > > in > > >> > > > > > > this > > >> > > > > > > > > > > mailing > > >> > > > > > > > > > > > > list > > >> > > > > > > > > > > > > > > > > > thread.) > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > Looking forward to your > > >> > > feedbacks. > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > Thank you~ > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > Xintong Song > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > [1] > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > >> > > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > >> > > > https://cwiki.apache.org/confluence/display/FLINK/FLIP-49%3A+Unified+Memory+Configuration+for+TaskExecutors > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > [2] > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > >> > > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > >> > > > https://docs.google.com/document/d/1o4KvyyXsQMGUastfPin3ZWeUXWsJgoL7piqp1fFYJvA/edit?usp=sharing > > >> > > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > > >> > > > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > >> > > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > >> > > > > > >
