Thanks Lijie and ZhuZhu for the explanation. I just overlooked the "MARK_BLOCKLISTED". For tasks level, it is indeed some functionalities the external tools(e.g. kubectl taint) could not support.
Best, Yang Lijie Wang <wangdachui9...@gmail.com> 于2022年5月6日周五 22:18写道： > Thanks for your feedback, Jiangang and Martijn. > > @Jiangang > > > > For auto-detecting, I wonder how to make the strategy and mark a node > blocked? > > In fact, we currently plan to not support auto-detection in this FLIP. The > part about auto-detection may be continued in a separate FLIP in the > future. Some guys have the same concerns as you, and the correctness and > necessity of auto-detection may require further discussion in the future. > > > In session mode, multi jobs can fail on the same bad node and the node > should be marked blocked. > By design, the blocklist information will be shared among all jobs in a > cluster/session. The JM will sync blocklist information with RM. > > @Martijn > > > I agree with Yang Wang on this. > As Zhu Zhu and I mentioned above, we think the MARK_BLOCKLISTED(Just limits > the load of the node and does not kill all the processes on it) is also > important, and we think that external systems (*yarn rmadmin or kubectl > taint*) cannot support it. So we think it makes sense even only *manually*. > > > I also agree with Chesnay that magical mechanisms are indeed super hard > to get right. > Yes, as you see, Jiangang(and a few others) have the same concern. > However, we currently plan to not support auto-detection in this FLIP, and > only *manually*. In addition, I'd like to say that the FLIP provides a > mechanism to support MARK_BLOCKLISTED and > MARK_BLOCKLISTED_AND_EVACUATE_TASKS, > the auto-detection may be done by external systems. > > Best, > Lijie > > Martijn Visser <mart...@ververica.com> 于2022年5月6日周五 19:04写道： > > > > If we only support to block nodes manually, then I could not see > > the obvious advantages compared with current SRE's approach(via *yarn > > rmadmin or kubectl taint*). > > > > I agree with Yang Wang on this. > > > > > To me this sounds yet again like one of those magical mechanisms that > > will rarely work just right. > > > > I also agree with Chesnay that magical mechanisms are indeed super hard > to > > get right. > > > > Best regards, > > > > Martijn > > > > On Fri, 6 May 2022 at 12:03, Jiangang Liu <liujiangangp...@gmail.com> > > wrote: > > > >> Thanks for the valuable design. The auto-detecting can decrease great > work > >> for us. We have implemented the similar feature in our inner flink > >> version. > >> Below is something that I care about: > >> > >> 1. For auto-detecting, I wonder how to make the strategy and mark a > >> node > >> blocked? Sometimes the blocked node is hard to be detected, for > >> example, > >> the upper node or the down node will be blocked when network > >> unreachable. > >> 2. I see that the strategy is made in JobMaster side. How about > >> implementing the similar logic in resource manager? In session mode, > >> multi > >> jobs can fail on the same bad node and the node should be marked > >> blocked. > >> If the job makes the strategy, the node may be not marked blocked if > >> the > >> fail times don't exceed the threshold. > >> > >> > >> Zhu Zhu <reed...@gmail.com> 于2022年5月5日周四 23:35写道： > >> > >> > Thank you for all your feedback! > >> > > >> > Besides the answers from Lijie, I'd like to share some of my thoughts: > >> > 1. Whether to enable automatical blocklist > >> > Generally speaking, it is not a goal of FLIP-224. > >> > The automatical way should be something built upon the blocklist > >> > mechanism and well decoupled. It was designed to be a configurable > >> > blocklist strategy, but I think we can further decouple it by > >> > introducing a abnormal node detector, as Becket suggested, which just > >> > uses the blocklist mechanism once bad nodes are detected. However, it > >> > should be a separate FLIP with further dev discussions and feedback > >> > from users. I also agree with Becket that different users have > different > >> > requirements, and we should listen to them. > >> > > >> > 2. Is it enough to just take away abnormal nodes externally > >> > My answer is no. As Lijie has mentioned, we need a way to avoid > >> > deploying tasks to temporary hot nodes. In this case, users may just > >> > want to limit the load of the node and do not want to kill all the > >> > processes on it. Another case is the speculative execution[1] which > >> > may also leverage this feature to avoid starting mirror tasks on slow > >> > nodes. > >> > > >> > Thanks, > >> > Zhu > >> > > >> > [1] > >> > > >> > https://cwiki.apache.org/confluence/display/FLINK/FLIP-168%3A+Speculative+execution+for+Batch+Job > >> > > >> > Lijie Wang <wangdachui9...@gmail.com> 于2022年5月5日周四 15:56写道： > >> > > >> > > > >> > > Hi everyone, > >> > > > >> > > > >> > > Thanks for your feedback. > >> > > > >> > > > >> > > There's one detail that I'd like to re-emphasize here because it can > >> > affect the value and design of the blocklist mechanism (perhaps I > should > >> > highlight it in the FLIP). We propose two actions in FLIP: > >> > > > >> > > 1) MARK_BLOCKLISTED: Just mark the task manager or node as blocked. > >> > Future slots should not be allocated from the blocked task manager or > >> node. > >> > But slots that are already allocated will not be affected. A typical > >> > application scenario is to mitigate machine hotspots. In this case, we > >> hope > >> > that subsequent resource allocations will not be on the hot machine, > but > >> > tasks currently running on it should not be affected. > >> > > > >> > > 2) MARK_BLOCKLISTED_AND_EVACUATE_TASKS: Mark the task manager or > node > >> as > >> > blocked, and evacuate all tasks on it. Evacuated tasks will be > >> restarted on > >> > non-blocked task managers. > >> > > > >> > > For the above 2 actions, the former may more highlight the meaning > of > >> > this FLIP, because the external system cannot do that. > >> > > > >> > > > >> > > Regarding *Manually* and *Automatically*, I basically agree with > >> @Becket > >> > Qin: different users have different answers. Not all users’ deployment > >> > environments have a special external system that can perform the > anomaly > >> > detection. In addition, adding pluggable/optional auto-detection > doesn't > >> > require much extra work on top of manual specification. > >> > > > >> > > > >> > > I will answer your other questions one by one. > >> > > > >> > > > >> > > @Yangze > >> > > > >> > > a) I think you are right, we do not need to expose the > >> > `cluster.resource-blocklist.item.timeout-check-interval` to users. > >> > > > >> > > b) We can abstract the `notifyException` to a separate interface > >> (maybe > >> > BlocklistExceptionListener), and the ResourceManagerBlocklistHandler > can > >> > implement it in the future. > >> > > > >> > > > >> > > @Martijn > >> > > > >> > > a) I also think the manual blocking should be done by cluster > >> operators. > >> > > > >> > > b) I think manual blocking makes sense, because according to my > >> > experience, users are often the first to perceive the machine problems > >> > (because of job failover or delay), and they will contact cluster > >> operators > >> > to solve it, or even tell the cluster operators which machine is > >> > problematic. From this point of view, I think the people who really > need > >> > the manual blocking are the users, and it’s just performed by the > >> cluster > >> > operator, so I think the manual blocking makes sense. > >> > > > >> > > > >> > > @Chesnay > >> > > > >> > > We need to touch the logic of JM/SlotPool, because for > >> MARK_BLOCKLISTED > >> > , we need to know whether the slot is blocklisted when the task is > >> > FINISHED/CANCELLED/FAILED. If so, SlotPool should release the slot > >> > directly to avoid assigning other tasks (of this job) on it. If we > only > >> > maintain the blocklist information on the RM, JM needs to retrieve it > by > >> > RPC. I think the performance overhead of that is relatively large, so > I > >> > think it's worth maintaining the blocklist information on the JM side > >> and > >> > syncing them. > >> > > > >> > > > >> > > @Роман > >> > > > >> > > a) “Probably storing inside Zookeeper/Configmap might be helpful > >> > here.” Can you explain it in detail? I don't fully understand that. > In > >> my > >> > opinion, non-active and active are the same, and no special treatment > is > >> > required. > >> > > > >> > > b) I agree with you, the `endTimestamp` makes sense, I will add it > to > >> > FLIP. > >> > > > >> > > > >> > > @Yang > >> > > > >> > > As mentioned above, AFAK, the external system cannot support the > >> > MARK_BLOCKLISTED action. > >> > > > >> > > > >> > > Looking forward to your further feedback. > >> > > > >> > > > >> > > Best, > >> > > > >> > > Lijie > >> > > > >> > > > >> > > Yang Wang <danrtsey...@gmail.com> 于2022年5月3日周二 21:09写道： > >> > >> > >> > >> Thanks Lijie and Zhu for creating the proposal. > >> > >> > >> > >> I want to share some thoughts about Flink cluster operations. > >> > >> > >> > >> In the production environment, the SRE(aka Site Reliability > Engineer) > >> > >> already has many tools to detect the unstable nodes, which could > take > >> > the > >> > >> system logs/metrics into consideration. > >> > >> Then they use graceful-decomission in YARN and taint in K8s to > >> prevent > >> > new > >> > >> allocations on these unstable nodes. > >> > >> At last, they will evict all the containers and pods running on > these > >> > nodes. > >> > >> This mechanism also works for planned maintenance. So I am afraid > >> this > >> > is > >> > >> not the typical use case for FLIP-224. > >> > >> > >> > >> If we only support to block nodes manually, then I could not see > >> > >> the obvious advantages compared with current SRE's approach(via > *yarn > >> > >> rmadmin or kubectl taint*). > >> > >> At least, we need to have a pluggable component which could expose > >> the > >> > >> potential unstable nodes automatically and block them if enabled > >> > explicitly. > >> > >> > >> > >> > >> > >> Best, > >> > >> Yang > >> > >> > >> > >> > >> > >> > >> > >> Becket Qin <becket....@gmail.com> 于2022年5月2日周一 16:36写道： > >> > >> > >> > >> > Thanks for the proposal, Lijie. > >> > >> > > >> > >> > This is an interesting feature and discussion, and somewhat > related > >> > to the > >> > >> > design principle about how people should operate Flink. > >> > >> > > >> > >> > I think there are three things involved in this FLIP. > >> > >> > a) Detect and report the unstable node. > >> > >> > b) Collect the information of the unstable node and form a > >> > blocklist. > >> > >> > c) Take the action to block nodes. > >> > >> > > >> > >> > My two cents: > >> > >> > > >> > >> > 1. It looks like people all agree that Flink should have c). It > is > >> > not only > >> > >> > useful for cases of node failures, but also handy for some > planned > >> > >> > maintenance. > >> > >> > > >> > >> > 2. People have different opinions on b), i.e. who should be the > >> brain > >> > to > >> > >> > make the decision to block a node. I think this largely depends > on > >> > who we > >> > >> > talk to. Different users would probably give different answers. > For > >> > people > >> > >> > who do have a centralized node health management service, let > Flink > >> > do just > >> > >> > do a) and c) would be preferred. So essentially Flink would be > one > >> of > >> > the > >> > >> > sources that may detect unstable nodes, report it to that > service, > >> > and then > >> > >> > take the command from that service to block the problematic > nodes. > >> On > >> > the > >> > >> > other hand, for users who do not have such a service, simply > >> letting > >> > Flink > >> > >> > be clever by itself to block the suspicious nodes might be > desired > >> to > >> > >> > ensure the jobs are running smoothly. > >> > >> > > >> > >> > So that indicates a) and b) here should be pluggable / optional. > >> > >> > > >> > >> > In light of this, maybe it would make sense to have something > >> > pluggable > >> > >> > like a UnstableNodeReporter which exposes unstable nodes > actively. > >> (A > >> > more > >> > >> > general interface should be JobInfoReporter<T> which can be used > to > >> > report > >> > >> > any information of type <T>. But I'll just keep the scope > relevant > >> to > >> > this > >> > >> > FLIP here). Personally speaking, I think it is OK to have a > default > >> > >> > implementation of a reporter which just tells Flink to take > action > >> to > >> > block > >> > >> > problematic nodes and also unblocks them after timeout. > >> > >> > > >> > >> > Thanks, > >> > >> > > >> > >> > Jiangjie (Becket) Qin > >> > >> > > >> > >> > > >> > >> > On Mon, May 2, 2022 at 3:27 PM Роман Бойко <ro.v.bo...@gmail.com > > > >> > wrote: > >> > >> > > >> > >> > > Thanks for good initiative, Lijie and Zhu! > >> > >> > > > >> > >> > > If it's possible I'd like to participate in development. > >> > >> > > > >> > >> > > I agree with 3rd point of Konstantin's reply - we should > consider > >> > to move > >> > >> > > somehow the information of blocklisted nodes/TMs from active > >> > >> > > ResourceManager to non-active ones. Probably storing inside > >> > >> > > Zookeeper/Configmap might be helpful here. > >> > >> > > > >> > >> > > And I agree with Martijn that a lot of organizations don't want > >> to > >> > expose > >> > >> > > such API for a cluster user group. But I think it's necessary > to > >> > have the > >> > >> > > mechanism for unblocking the nodes/TMs anyway for avoiding > >> incorrect > >> > >> > > automatic behaviour. > >> > >> > > > >> > >> > > And another one small suggestion - I think it would be better > to > >> > extend > >> > >> > the > >> > >> > > *BlocklistedItem* class with the *endTimestamp* field and fill > it > >> > at the > >> > >> > > item creation. This simple addition will allow to: > >> > >> > > > >> > >> > > - > >> > >> > > > >> > >> > > Provide the ability to users to setup the exact time of > >> > blocklist end > >> > >> > > through RestAPI > >> > >> > > - > >> > >> > > > >> > >> > > Not being tied to a single value of > >> > >> > > *cluster.resource-blacklist.item.timeout* > >> > >> > > > >> > >> > > > >> > >> > > On Mon, 2 May 2022 at 14:17, Chesnay Schepler < > >> ches...@apache.org> > >> > >> > wrote: > >> > >> > > > >> > >> > > > I do share the concern between blurring the lines a bit. > >> > >> > > > > >> > >> > > > That said, I'd prefer to not have any auto-detection and only > >> > have an > >> > >> > > > opt-in mechanism > >> > >> > > > to manually block processes/nodes. To me this sounds yet > again > >> > like one > >> > >> > > > of those > >> > >> > > > magical mechanisms that will rarely work just right. > >> > >> > > > An external system can leverage way more information after > all. > >> > >> > > > > >> > >> > > > Moreover, I'm quite concerned about the complexity of this > >> > proposal. > >> > >> > > > Tracking on both the RM/JM side; syncing between components; > >> > >> > adjustments > >> > >> > > > to the > >> > >> > > > slot and resource protocol. > >> > >> > > > > >> > >> > > > In a way it seems overly complicated. > >> > >> > > > > >> > >> > > > If we look at it purely from an active resource management > >> > perspective, > >> > >> > > > then there > >> > >> > > > isn't really a need to touch the slot protocol at all (or in > >> fact > >> > to > >> > >> > > > anything in the JobMaster), > >> > >> > > > because there isn't any point in keeping around blocked TMs > in > >> the > >> > >> > first > >> > >> > > > place. > >> > >> > > > They'd just be idling, potentially shutting down after a > while > >> by > >> > the > >> > >> > RM > >> > >> > > > because of > >> > >> > > > it (unless we _also_ touch that logic). > >> > >> > > > Here the blocking of a process (be it by blocking the process > >> or > >> > node) > >> > >> > is > >> > >> > > > equivalent with shutting down the blocked process(es). > >> > >> > > > Once the block is lifted we can just spin it back up. > >> > >> > > > > >> > >> > > > And I do wonder whether we couldn't apply the same line of > >> > thinking to > >> > >> > > > standalone resource management. > >> > >> > > > Here being able to stop/restart a process/node manually > should > >> be > >> > a > >> > >> > core > >> > >> > > > requirement for a Flink deployment anyway. > >> > >> > > > > >> > >> > > > > >> > >> > > > On 02/05/2022 08:49, Martijn Visser wrote: > >> > >> > > > > Hi everyone, > >> > >> > > > > > >> > >> > > > > Thanks for creating this FLIP. I can understand the problem > >> and > >> > I see > >> > >> > > > value > >> > >> > > > > in the automatic detection and blocklisting. I do have some > >> > concerns > >> > >> > > with > >> > >> > > > > the ability to manually specify to be blocked resources. I > >> have > >> > two > >> > >> > > > > concerns; > >> > >> > > > > > >> > >> > > > > * Most organizations explicitly have a separation of > >> concerns, > >> > >> > meaning > >> > >> > > > that > >> > >> > > > > there's a group who's responsible for managing a cluster > and > >> > there's > >> > >> > a > >> > >> > > > user > >> > >> > > > > group who uses that cluster. With the introduction of this > >> > mechanism, > >> > >> > > the > >> > >> > > > > latter group now can influence the responsibility of the > >> first > >> > group. > >> > >> > > So > >> > >> > > > it > >> > >> > > > > can be possible that someone from the user group blocks > >> > something, > >> > >> > > which > >> > >> > > > > causes an outage (which could result in paging mechanism > >> > triggering > >> > >> > > etc) > >> > >> > > > > which impacts the first group. > >> > >> > > > > * How big is the group of people who can go through the > >> process > >> > of > >> > >> > > > manually > >> > >> > > > > identifying a node that isn't behaving as it should be? I > do > >> > think > >> > >> > this > >> > >> > > > > group is relatively limited. Does it then make sense to > >> > introduce > >> > >> > such > >> > >> > > a > >> > >> > > > > feature, which would only be used by a really small user > >> group > >> > of > >> > >> > > Flink? > >> > >> > > > We > >> > >> > > > > still have to maintain, test and support such a feature. > >> > >> > > > > > >> > >> > > > > I'm +1 for the autodetection features, but I'm leaning > >> towards > >> > not > >> > >> > > > exposing > >> > >> > > > > this to the user group but having this available strictly > for > >> > cluster > >> > >> > > > > operators. They could then also set up their > >> > paging/metrics/logging > >> > >> > > > system > >> > >> > > > > to take this into account. > >> > >> > > > > > >> > >> > > > > Best regards, > >> > >> > > > > > >> > >> > > > > Martijn Visser > >> > >> > > > > https://twitter.com/MartijnVisser82 > >> > >> > > > > https://github.com/MartijnVisser > >> > >> > > > > > >> > >> > > > > > >> > >> > > > > On Fri, 29 Apr 2022 at 09:39, Yangze Guo < > karma...@gmail.com > >> > > >> > wrote: > >> > >> > > > > > >> > >> > > > >> Thanks for driving this, Zhu and Lijie. > >> > >> > > > >> > >> > >> > > > >> +1 for the overall proposal. Just share some cents here: > >> > >> > > > >> > >> > >> > > > >> - Why do we need to expose > >> > >> > > > >> cluster.resource-blacklist.item.timeout-check-interval to > >> the > >> > user? > >> > >> > > > >> I think the semantics of > >> > `cluster.resource-blacklist.item.timeout` > >> > >> > is > >> > >> > > > >> sufficient for the user. How to guarantee the timeout > >> > mechanism is > >> > >> > > > >> Flink's internal implementation. I think it will be very > >> > confusing > >> > >> > and > >> > >> > > > >> we do not need to expose it to users. > >> > >> > > > >> > >> > >> > > > >> - ResourceManager can notify the exception of a task > >> manager to > >> > >> > > > >> `BlacklistHandler` as well. > >> > >> > > > >> For example, the slot allocation might fail in case the > >> target > >> > task > >> > >> > > > >> manager is busy or has a network jitter. I don't mean we > >> need > >> > to > >> > >> > cover > >> > >> > > > >> this case in this version, but we can also open a > >> > `notifyException` > >> > >> > in > >> > >> > > > >> `ResourceManagerBlacklistHandler`. > >> > >> > > > >> > >> > >> > > > >> - Before we sync the blocklist to ResourceManager, will > the > >> > slot of > >> > >> > a > >> > >> > > > >> blocked task manager continues to be released and > allocated? > >> > >> > > > >> > >> > >> > > > >> Best, > >> > >> > > > >> Yangze Guo > >> > >> > > > >> > >> > >> > > > >> On Thu, Apr 28, 2022 at 3:11 PM Lijie Wang < > >> > >> > wangdachui9...@gmail.com> > >> > >> > > > >> wrote: > >> > >> > > > >>> Hi Konstantin, > >> > >> > > > >>> > >> > >> > > > >>> Thanks for your feedback. I will response your 4 remarks: > >> > >> > > > >>> > >> > >> > > > >>> > >> > >> > > > >>> 1) Thanks for reminding me of the controversy. I think > >> > “BlockList” > >> > >> > is > >> > >> > > > >> good > >> > >> > > > >>> enough, and I will change it in FLIP. > >> > >> > > > >>> > >> > >> > > > >>> > >> > >> > > > >>> 2) Your suggestion for the REST API is a good idea. Based > >> on > >> > the > >> > >> > > > above, I > >> > >> > > > >>> would change REST API as following: > >> > >> > > > >>> > >> > >> > > > >>> POST/GET <host>/blocklist/nodes > >> > >> > > > >>> > >> > >> > > > >>> POST/GET <host>/blocklist/taskmanagers > >> > >> > > > >>> > >> > >> > > > >>> DELETE <host>/blocklist/node/<identifier> > >> > >> > > > >>> > >> > >> > > > >>> DELETE <host>/blocklist/taskmanager/<identifier> > >> > >> > > > >>> > >> > >> > > > >>> > >> > >> > > > >>> 3) If a node is blocking/blocklisted, it means that all > >> task > >> > >> > managers > >> > >> > > > on > >> > >> > > > >>> this node are blocklisted. All slots on these TMs are not > >> > >> > available. > >> > >> > > > This > >> > >> > > > >>> is actually a bit like TM losts, but these TMs are not > >> really > >> > lost, > >> > >> > > > they > >> > >> > > > >>> are in an unavailable status, and they are still > registered > >> > in this > >> > >> > > > flink > >> > >> > > > >>> cluster. They will be available again once the > >> corresponding > >> > >> > > blocklist > >> > >> > > > >> item > >> > >> > > > >>> is removed. This behavior is the same in > active/non-active > >> > >> > clusters. > >> > >> > > > >>> However in the active clusters, these TMs may be released > >> due > >> > to > >> > >> > idle > >> > >> > > > >>> timeouts. > >> > >> > > > >>> > >> > >> > > > >>> > >> > >> > > > >>> 4) For the item timeout, I prefer to keep it. The reasons > >> are > >> > as > >> > >> > > > >> following: > >> > >> > > > >>> a) The timeout will not affect users adding or removing > >> items > >> > via > >> > >> > > REST > >> > >> > > > >> API, > >> > >> > > > >>> and users can disable it by configuring it to > >> Long.MAX_VALUE . > >> > >> > > > >>> > >> > >> > > > >>> b) Some node problems can recover after a period of time > >> > (such as > >> > >> > > > machine > >> > >> > > > >>> hotspots), in which case users may prefer that Flink can > do > >> > this > >> > >> > > > >>> automatically instead of requiring the user to do it > >> manually. > >> > >> > > > >>> > >> > >> > > > >>> > >> > >> > > > >>> Best, > >> > >> > > > >>> > >> > >> > > > >>> Lijie > >> > >> > > > >>> > >> > >> > > > >>> Konstantin Knauf <kna...@apache.org> 于2022年4月27日周三 > >> 19:23写道： > >> > >> > > > >>> > >> > >> > > > >>>> Hi Lijie, > >> > >> > > > >>>> > >> > >> > > > >>>> I think, this makes sense and +1 to only support > manually > >> > blocking > >> > >> > > > >>>> taskmanagers and nodes. Maybe the different strategies > can > >> > also be > >> > >> > > > >>>> maintained outside of Apache Flink. > >> > >> > > > >>>> > >> > >> > > > >>>> A few remarks: > >> > >> > > > >>>> > >> > >> > > > >>>> 1) Can we use another term than "bla.cklist" due to the > >> > >> > controversy > >> > >> > > > >> around > >> > >> > > > >>>> the term? [1] There was also a Jira Ticket about this > >> topic a > >> > >> > while > >> > >> > > > >> back > >> > >> > > > >>>> and there was generally a consensus to avoid the term > >> > blacklist & > >> > >> > > > >> whitelist > >> > >> > > > >>>> [2]? We could use "blocklist" "denylist" or > "quarantined" > >> > >> > > > >>>> 2) For the REST API, I'd prefer a slightly different > >> design > >> > as > >> > >> > verbs > >> > >> > > > >> like > >> > >> > > > >>>> add/remove often considered an anti-pattern for REST > APIs. > >> > POST > >> > >> > on a > >> > >> > > > >> list > >> > >> > > > >>>> item is generally the standard to add items. DELETE on > the > >> > >> > > individual > >> > >> > > > >>>> resource is standard to remove an item. > >> > >> > > > >>>> > >> > >> > > > >>>> POST <host>/quarantine/items > >> > >> > > > >>>> DELETE <host>/quarantine/items/<itemidentifier> > >> > >> > > > >>>> > >> > >> > > > >>>> We could also consider to separate taskmanagers and > nodes > >> in > >> > the > >> > >> > > REST > >> > >> > > > >> API > >> > >> > > > >>>> (and internal data structures). Any opinion on this? > >> > >> > > > >>>> > >> > >> > > > >>>> POST/GET <host>/quarantine/nodes > >> > >> > > > >>>> POST/GET <host>/quarantine/taskmanager > >> > >> > > > >>>> DELETE <host>/quarantine/nodes/<identifier> > >> > >> > > > >>>> DELETE <host>/quarantine/taskmanager/<identifier> > >> > >> > > > >>>> > >> > >> > > > >>>> 3) How would blocking nodes behave with non-active > >> resource > >> > >> > > managers, > >> > >> > > > >> i.e. > >> > >> > > > >>>> standalone or reactive mode? > >> > >> > > > >>>> > >> > >> > > > >>>> 4) To keep the implementation even more minimal, do we > >> need > >> > the > >> > >> > > > timeout > >> > >> > > > >>>> behavior? If items are added/removed manually we could > >> > delegate > >> > >> > this > >> > >> > > > >> to the > >> > >> > > > >>>> user easily. In my opinion the timeout behavior would > >> better > >> > fit > >> > >> > > into > >> > >> > > > >>>> specific strategies at a later point. > >> > >> > > > >>>> > >> > >> > > > >>>> Looking forward to your thoughts. > >> > >> > > > >>>> > >> > >> > > > >>>> Cheers and thank you, > >> > >> > > > >>>> > >> > >> > > > >>>> Konstantin > >> > >> > > > >>>> > >> > >> > > > >>>> [1] > >> > >> > > > >>>> > >> > >> > > > >>>> > >> > >> > > > >> > >> > >> > > > > >> > >> > > > >> > >> > > >> > > >> > https://en.wikipedia.org/wiki/Blacklist_(computing)#Controversy_over_use_of_the_term > >> > >> > > > >>>> [2] https://issues.apache.org/jira/browse/FLINK-18209 > >> > >> > > > >>>> > >> > >> > > > >>>> Am Mi., 27. Apr. 2022 um 04:04 Uhr schrieb Lijie Wang < > >> > >> > > > >>>> wangdachui9...@gmail.com>: > >> > >> > > > >>>> > >> > >> > > > >>>>> Hi all, > >> > >> > > > >>>>> > >> > >> > > > >>>>> Flink job failures may happen due to cluster node > issues > >> > >> > > > >> (insufficient > >> > >> > > > >>>> disk > >> > >> > > > >>>>> space, bad hardware, network abnormalities). Flink will > >> > take care > >> > >> > > of > >> > >> > > > >> the > >> > >> > > > >>>>> failures and redeploy the tasks. However, due to data > >> > locality > >> > >> > and > >> > >> > > > >>>> limited > >> > >> > > > >>>>> resources, the new tasks are very likely to be > redeployed > >> > to the > >> > >> > > same > >> > >> > > > >>>>> nodes, which will result in continuous task > abnormalities > >> > and > >> > >> > > affect > >> > >> > > > >> job > >> > >> > > > >>>>> progress. > >> > >> > > > >>>>> > >> > >> > > > >>>>> Currently, Flink users need to manually identify the > >> > problematic > >> > >> > > > >> node and > >> > >> > > > >>>>> take it offline to solve this problem. But this > approach > >> has > >> > >> > > > >> following > >> > >> > > > >>>>> disadvantages: > >> > >> > > > >>>>> > >> > >> > > > >>>>> 1. Taking a node offline can be a heavy process. Users > >> may > >> > need > >> > >> > to > >> > >> > > > >>>> contact > >> > >> > > > >>>>> cluster administors to do this. The operation can even > be > >> > >> > dangerous > >> > >> > > > >> and > >> > >> > > > >>>> not > >> > >> > > > >>>>> allowed during some important business events. > >> > >> > > > >>>>> > >> > >> > > > >>>>> 2. Identifying and solving this kind of problems > manually > >> > would > >> > >> > be > >> > >> > > > >> slow > >> > >> > > > >>>> and > >> > >> > > > >>>>> a waste of human resources. > >> > >> > > > >>>>> > >> > >> > > > >>>>> To solve this problem, Zhu Zhu and I propose to > >> introduce a > >> > >> > > blacklist > >> > >> > > > >>>>> mechanism for Flink to filter out problematic > resources. > >> > >> > > > >>>>> > >> > >> > > > >>>>> > >> > >> > > > >>>>> You can find more details in FLIP-224[1]. Looking > forward > >> > to your > >> > >> > > > >>>> feedback. > >> > >> > > > >>>>> [1] > >> > >> > > > >>>>> > >> > >> > > > >>>>> > >> > >> > > > >> > >> > >> > > > > >> > >> > > > >> > >> > > >> > > >> > https://cwiki.apache.org/confluence/display/FLINK/FLIP-224%3A+Blacklist+Mechanism > >> > >> > > > >>>>> > >> > >> > > > >>>>> Best, > >> > >> > > > >>>>> > >> > >> > > > >>>>> Lijie > >> > >> > > > >>>>> > >> > >> > > > > >> > >> > > > > >> > >> > > > >> > >> > > >> > > >> > > >
