Hi Jason, I build kafka-client and tried using it but my producers and consumers started throwing below exception. Is 0.10 not going to be compatible with brokers on version 0.9.0.1? or do i need to make some config changes to producers / consumers to make them compatible with brokers on old version? or do i need to upgrade brokers to new version as well?
org.apache.kafka.common.protocol.types.SchemaException: Error reading field 'brokers': Error reading field 'host': Error reading string of length 17995, only 145 bytes available at org.apache.kafka.common.protocol.types.Schema.read(Schema.java:75) at org.apache.kafka.clients.NetworkClient.parseResponse(NetworkClient.java:380) at org.apache.kafka.clients.NetworkClient.handleCompletedReceives(NetworkClient.java:449) Regards, Vinay Sharma On Thu, Apr 28, 2016 at 12:32 AM, Jason Gustafson <ja...@confluent.io> wrote: > Hey Vinay, > > Any chance you can run the same test against trunk? I'm guessing this might > be caused by a bug in the 0.9 consumer which basically causes some requests > to fail when a bunch of them are sent to the broker at the same time. > > -Jason > > On Wed, Apr 27, 2016 at 1:02 PM, vinay sharma <vinsharma.t...@gmail.com> > wrote: > > > Hi Jason, > > > > This makes sense.We use 0.9.0.1 and we do have session timeout set a bit > > high but nothing can guarantee that there will be no case when processing > > may not go higher than session timeout. I am trying to test a proactive > > commit approach to handle such cases when processing takes unusually long > > time. To keep consumer's session alive during long processing time i > > proactively commitSync processed records every 15 seconds. Session > timeout > > i kept is 30000. > > > > *Problem:-* > > With heart beat interval is 3000 then i expect a hearbeat request to be > > sent on each proactive commit which happens every 15 seconds. In my > tests i > > see that this does not happen always. I see a time window which is > greater > > than 30 seconds where no hearbeat is sent even thought there were commits > > in this duration. After this window i see a couple of successful > heartbeat > > responses till the end of poll but as soon as i poll again and call > > commitSync in next poll i get "ILLEGAL_GENERATION" error. This error > always > > happen just after meta refresh or in next poll processing after a meta > > refresh. I am attaching logs where i kept meta refresh interval 40000, > > 90000, 500000. > > > > *Test results *:- > > Test with meta refresh 40000 ms ran around 70 seconds from 1st poll. > > Test with meta refresh 90000 ms ran around 120 seconds from 1st poll. > > Test with meta refresh 500000 ms ran around 564 seconds from 1st poll. > > > > Every test falls in line with above test cases where generation is marked > > dead some time after a meta refresh. Meta refresh before 1st poll does > not > > create any issue but the ones after poll and during long processing do. > > > > *Environment:-* > > My setup has 3 brokers 1 zk. Topic has 3 partitions ans has replication > > factor 3. Messages are already published to topic. > > > > *Logic used in test cases :- * > > On each poll I initialize a map with current committed offset position of > > partitions being consumed. I update this map after each record processing > > and use this map to proactively commit every 15 seconds. Map is > initialized > > again after a proactive commit. > > > > I am not sure what is wrong here but i do not see any issue in code or > > offset commits going on. Log files and a class with main method are > > attached for your reference. > > > > Regards, > > Vinay Sharma > > > > > > > > On Wed, Apr 27, 2016 at 2:46 PM, Jason Gustafson <ja...@confluent.io> > > wrote: > > > >> Hi Vinay, > >> > >> Answers below: > >> > >> 1) Is it correct to say that each commitSync will trigger a > >> HeartBeatTask? > >> > If there is no hear beat sent in past since specified heartbeat > interval > >> > then i should see a successful heartbeat response or failure message > in > >> > logs near to commitSync success log? > >> > >> > >> Not quite. Heartbeats are sent periodically according to the > >> heartbeat.interval.ms configuration. However, since the consumer has no > >> background thread, they can only be sent in API calls such as poll() or > >> commitSync(). So calling commitSync() may or may not result in a > heartbeat > >> depending only on whether one is "due." > >> > >> 2) is it correct to say that Meta Data refresh will not act as > heartbeat, > >> > will not trigger heartBeatTask and will not reset heartBeatTask? > >> > >> > >> That is correct. Metadata refreshes are not related to heartbeats. > >> > >> 3) Where does a consumer session maintained? Lets say my consumer is > >> > listening to 3 partitions on a 3 broker cluster where each broker is > >> leader > >> > of 1 partition. So will each of the brokers will have a session for my > >> > consumer or is it just 1 session maintained somewhere in common like > >> > zookeeper? > >> > >> > >> One of the brokers serves as the "group coordinator." When the consumer > >> starts up, it sends a GroupCoordinator request to one of the brokers to > >> find out who the coordinator is. Currently, coordinators are chosen from > >> among the leaders of the partitions of the __consumer_offsets topic. > This > >> lets us take advantage of the leader election process to also handle > >> coordinator failures. The coordinator of each group maintains state for > >> the > >> group and keeps track of session timeouts. > >> > >> 4) In above setup, during a long processing if I commit a record through > >> > commmitSync which triggers a hear beat request and a successful > >> response is > >> > received for the same then what does this response means? does it mean > >> that > >> > my session with each broker is renewed? or does it mean that just the > >> > leader for partition of committed record knows that my consumer is > alive > >> > and consumer's session on other brokers will still timeout? > >> > >> > >> The coordinator is the only broker that is aware of a consumer's session > >> and all offset commits are sent to it. Successful heartbeats mean that > the > >> session is still active. Heartbeats are also used to let the consumer > >> discover when a rebalance has begun. If a new member joins the group, > then > >> the coordinator returns an error code in the heartbeat responses of the > >> active members to let them know that they need to rejoin the group so > that > >> partitions can be rebalanced. > >> > >> I wouldn't get too hung up on commit/heartbeat behavior. The crux of the > >> issue is that you need to call poll() often enough to avoid getting > timed > >> out by the coordinator. If you find this happening frequently, you > >> probably > >> need to increase session.timeout.ms. There's not really any downside to > >> doing so other than that hard failures (in which the consumer can't be > >> shutdown cleanly) will take a little longer to detect. Normal shutdown > >> doesn't have this problem. It can be difficult in 0.9 to ensure that > >> poll() > >> is called often enough since you don't have direct control over the > amount > >> of data returned in poll(), but we're adding an option > (max.poll.records) > >> in 0.10 which hopefully can be set conservatively enough to make this > >> problem go away. > >> > >> -Jason > >> > >> On Wed, Apr 27, 2016 at 7:11 AM, vinay sharma <vinsharma.t...@gmail.com > > > >> wrote: > >> > >> > Hey, > >> > > >> > I am working on a simplified test case to check if there is any issue > >> in my > >> > code. Just to make sure that any of my assumptions are not wrong, it > >> will > >> > be great if you can please help me in finding answers to following > >> > queries:- > >> > > >> > 1) Is it correct to say that each commitSync will trigger a > >> HeartBeatTask? > >> > If there is no hear beat sent in past since specified heartbeat > interval > >> > then i should see a successful heartbeat response or failure message > in > >> > logs near to commitSync success log? > >> > 2) is it correct to say that Meta Data refresh will not act as > >> heartbeat, > >> > will not trigger heartBeatTask and will not reset heartBeatTask? > >> > 3) Where does a consumer session maintained? Lets say my consumer is > >> > listening to 3 partitions on a 3 broker cluster where each broker is > >> leader > >> > of 1 partition. So will each of the brokers will have a session for my > >> > consumer or is it just 1 session maintained somewhere in common like > >> > zookeeper? > >> > 4) In above setup, during a long processing if I commit a record > through > >> > commmitSync which triggers a hear beat request and a successful > >> response is > >> > received for the same then what does this response means? does it mean > >> that > >> > my session with each broker is renewed? or does it mean that just the > >> > leader for partition of committed record knows that my consumer is > alive > >> > and consumer's session on other brokers will still timeout? > >> > > >> > Regards, > >> > Vinay Sharma > >> > > >> > On Tue, Apr 26, 2016 at 2:38 PM, Jason Gustafson <ja...@confluent.io> > >> > wrote: > >> > > >> > > Hey Vinay, > >> > > > >> > > Are you saying that heartbeats are not sent while a metadata refresh > >> is > >> > in > >> > > progress? Do you have any logs which show us the apparent problem? > >> > > > >> > > Thanks, > >> > > Jason > >> > > > >> > > On Tue, Apr 26, 2016 at 8:18 AM, vinay sharma < > >> vinsharma.t...@gmail.com> > >> > > wrote: > >> > > > >> > > > Hi Ismael, > >> > > > > >> > > > Treating commitSync as heartbeat will definitely resolve the issue > >> i am > >> > > > facing but the reason behind my issue does not seem to be what > >> > mentioned > >> > > in > >> > > > defect (i.e frequent commitSync requests). > >> > > > > >> > > > I am sending CommitSync periodically only to keep my session alive > >> when > >> > > my > >> > > > consumer is still processing records and is close to session time > >> out > >> > > > (tried 10th / 12th / 15th / 20th second after poll called where > >> session > >> > > > time is 30). I see heartbeat response received in logs along with > >> each > >> > > > commitSync call but this stops after a meta data refresh request > is > >> > > issued. > >> > > > I see in logs that commit goes successful but no heartbeat > response > >> > > > received message in logs after meta refresh till next poll. > >> > > > > >> > > > Regards, > >> > > > Vinay Sharma > >> > > > > >> > > > On Mon, Apr 25, 2016 at 5:06 PM, Ismael Juma <ism...@juma.me.uk> > >> > wrote: > >> > > > > >> > > > > Hi Vinay, > >> > > > > > >> > > > > This was fixed via > >> https://issues.apache.org/jira/browse/KAFKA-3470 > >> > > > (will > >> > > > > be part of 0.10.0.0). > >> > > > > > >> > > > > Ismael > >> > > > > > >> > > > > > >> > > > > > >> > > > > On Mon, Apr 25, 2016 at 1:52 PM, vinay sharma < > >> > > vinsharma.t...@gmail.com> > >> > > > > wrote: > >> > > > > > >> > > > > > Hello, > >> > > > > > > >> > > > > > I am using client API 0.9.0.1 and facing an issue. As per my > >> logs > >> > it > >> > > > > seems > >> > > > > > that on each commitSync(Offsets) a heartbeat request is sent > but > >> > > after > >> > > > a > >> > > > > > metada refresh request till next poll(), commits do not send > any > >> > > > hearbeat > >> > > > > > request. > >> > > > > > > >> > > > > > KafkaConsumers i create sometimes get session time out due to > no > >> > > > hearbeat > >> > > > > > specially during longer processing times. I call > >> > CommitSync(offsets) > >> > > > > after > >> > > > > > regular intervals to keep session alive when processing takes > >> > longer > >> > > > than > >> > > > > > usual. Every thing works fine if commit intervals are very > >> small or > >> > > if > >> > > > i > >> > > > > > commit after each record but if i commit lets say every 12 > >> seconds > >> > > and > >> > > > 30 > >> > > > > > seconds is session time then i can see consumer getting timed > >> out > >> > > > > > sometimes. > >> > > > > > > >> > > > > > Any help or pointers will be much appreciated. Thanks in > >> advance. > >> > > > > > > >> > > > > > Regards, > >> > > > > > Vinay sharma > >> > > > > > > >> > > > > > >> > > > > >> > > > >> > > >> > > > > >
