Yes you are right. I misread the code. So the only thing that can explain the behavior you are seeing is that may be there are many segments that need to be deleted all at once. Can you try may be reducing the retention.ms in smaller intervals - like reduce it to 9 days from 10 days and see if the brokers are fine.
On Tue, Aug 18, 2015 at 12:48 AM Zhao Weinan <zhaow...@gmail.com> wrote: > Hi Kishore Senji, > > Did you constantly send messages to your test topic? Or just one time send? > I've just did some test, the log.lastModified is updated with every message > received (or every flush to disk at least). So I think if your interval > between two neibouring messages is never smaller than retention.ms, then > your current segments should never be deleted. > > The wired thing is the offset of one partition in my data-loss-topic became > to be zero, while offsets in other partition are normally minimum... > > 2015-08-18 14:45 GMT+08:00 Kishore Senji <kse...@gmail.com>: > > > It is log.deleteOldSegments(startMs - _.lastModified > > > log.config.retentionMs) > > > > You might have missed the startMs. > > > > I have tested it myself. I created a test topic with retention.ms equal > to > > 20 minutes and added some messages. Later I changed the retention.ms to > 2 > > min. I can see whenever the delete thread runs (every five min), it > deletes > > even the latest Segment because that Segment age is older than > > retention.ms > > > > > > On Mon, Aug 17, 2015 at 11:30 PM, Zhao Weinan <zhaow...@gmail.com> > wrote: > > > > > Hi Kishore Senji, > > > > > > The size of segement file is default 1GB. > > > > > > According to the LogManager.scala#cleanupExpiredSegments, Kafka will > only > > > delete segments whose lastModTime is older than retention.ms, so I > dont > > > think this is the reason for my data loss. Actually I lost some data in > > > topic other than the topic I reduced the retention... > > > > > > I dont know whether destage these several GB files will cause this kind > > of > > > system chattering, though we do use not very fancy hardwares. > > > > > > 2015-08-18 7:48 GMT+08:00 Kishore Senji <kse...@gmail.com>: > > > > > > > What is the size of the segment file? You are reducing the retention > > from > > > > 10 days to 1 day. The moment you do this, it will delete all segments > > > which > > > > are older than 1 day. So for example, if your latest segment is older > > > than > > > > 1 day and if there are consumers which are still catching up (let us > > say > > > 10 > > > > min lag), Kafka will roll over and delete the older segments and > there > > is > > > > potential for data loss. One pattern could be to make sure you change > > > this > > > > config parameter only when a new segment is created and all consumers > > are > > > > on the new segment and also make sure all clients will be done with > the > > > > segment before the file is deleted. > > > > > > > > My guess is that your segment file is huge and the OS may be taking a > > > long > > > > time to destage the file cache on to disk before letting it to be > > > deleted. > > > > This could be the reason for long pause which could be causing the Zk > > > > connections to be timed out. > > > > > > > > > > > > > > > > On Mon, Aug 17, 2015 at 6:59 AM Zhao Weinan <zhaow...@gmail.com> > > wrote: > > > > > > > > > Hi Kishore Senji, > > > > > > > > > > Thanks for the reply. > > > > > > > > > > Do you have some suggestions before the fix came up? Try not to > > modify > > > > the > > > > > retention.ms? Or disable the auto rebalance? Cause this problem is > > > 100% > > > > > reproduceable in my scenario (two times got dead lock in two > > > > retention.ms > > > > > modification), and I even found some data loss which I'm still > > looking > > > > for > > > > > the reason. > > > > > > > > > > Any idea on why shrinking the retention.ms causes the network > > > unstable? > > > > > > > > > > And yes I use the comma for clarity :) > > > > > > > > > > 2015-08-17 8:59 GMT+08:00 Kishore Senji <kse...@gmail.com>: > > > > > > > > > > > Interesting problem you ran in to. It seems like this broker was > > > chosen > > > > > as > > > > > > the Controller and onControllerFailure() method was called. This > > will > > > > > > schedule the checkAndTriggerPartitionRebalance method to execute > > > after > > > > 5 > > > > > > seconds (when auto rebalance enabled). In the mean time this > broker > > > > lost > > > > > > zookeeper connection and so this broker resigns from the > Controller > > > > > status > > > > > > and so the onControllerResignation() method is called and this > > method > > > > > will > > > > > > try to shutdown the auto rebalance executor. But it is doing it > by > > > > > holding > > > > > > the lock and this is what caused the dead lock in your case. > > > > > > > > > > > > I do not think we need to hold the lock to shutdown the executor. > > > This > > > > > > could be the fix we might need. > > > > > > > > > > > > retention.ms config parameter should not have commas in the > value. > > > Are > > > > > you > > > > > > just using it here to clarify for us. > > > > > > > > > > > > It so happened in your > > > > > > On Sun, Aug 16, 2015 at 1:52 AM Zhao Weinan <zhaow...@gmail.com> > > > > wrote: > > > > > > > > > > > > > Hi guys, > > > > > > > > > > > > > > I got this problem, after changing one topic's config to > > > > > > > retention.ms=86,400,000 > > > > > > > from 864,000,000, the brokers start to shedule and do deletions > > of > > > > > > outdated > > > > > > > index of that topic. > > > > > > > > > > > > > > Then for some reason some brokers' connection with zookeeper > were > > > > > > expired, > > > > > > > suddenly lots of ERRORs showed up in logs/server.log: At > > controller > > > > > > > broker(id=5) are: > > > > > > > > > > > > > > > *ERROR [ReplicaFetcherThread-2-4], Error for partition > > [XXXXX,4] > > > to > > > > > > > broker > > > > > > > > 4:class kafka.common.NotLeaderForPartitionException > > > > > > > > (kafka.server.ReplicaFetcherThread).* > > > > > > > > > > > > > > > At other broker which the controller broker try to fetch are: > > > > > > > > > > > > > > > *[Replica Manager on Broker 4]: Fetch request with > correlation > > id > > > > > > 1920630 > > > > > > > > from client ReplicaFetcherThread-2-4 on partition [XXXXX,4] > > > failed > > > > > due > > > > > > to > > > > > > > > Leader not local for partition [XXXXXXX,4] on broker 4 > > > > > > > > (kafka.server.ReplicaManager).* > > > > > > > > > > > > > > > > > > > > > > In controller broker's server.log there are zk reconnections: > > > > > > > > > > > > > > > *INFO Client session timed out, have not heard from server in > > > > 5126ms > > > > > > for > > > > > > > > sessionid 0x54e0aaa9582b8e4, closing socket connection and > > > > attempting > > > > > > > > reconnect (org.apache.zookeeper.ClientCnxn)* > > > > > > > > *INFO zookeeper state changed (Disconnected) > > > > > > > > (org.I0Itec.zkclient.ZkClient)* > > > > > > > > *NFO Opening socket connection to server xxxxxxxxxxx. Will > not > > > > > attempt > > > > > > to > > > > > > > > authenticate using SASL (java.lang.SecurityException: Unable > to > > > > > locate > > > > > > a > > > > > > > > login configuration) (org.apache.zookeeper.ClientCnxn)* > > > > > > > > *INFO Socket connection established to xxxxxxxxxxxxx, > > initiating > > > > > > session > > > > > > > > (org.apache.zookeeper.ClientCnxn)* > > > > > > > > *INFO Session establishment complete on server xxxxxxxxxx, > > > > sessionid > > > > > = > > > > > > > > 0x54e0aaa9582b8e4, negotiated timeout = 6000 > > > > > > > > (org.apache.zookeeper.ClientCnxn)* > > > > > > > > *INFO zookeeper state changed (SyncConnected) > > > > > > > > (org.I0Itec.zkclient.ZkClient)* > > > > > > > > > > > > > > > But on zookeeper /brokers/ids/ there is no controller broker's > id > > > 5. > > > > > > > > > > > > > > Then I tried to restart the controller broker, found the > process > > > > won't > > > > > > > quit. > > > > > > > > > > > > > > Then I jstacked it, found the broker process kind of stucked, > > some > > > > > > > keypoints pasted as below. It seems zk-client-expired-callback > > > > aquired > > > > > > the > > > > > > > controllerLock and wait the kafka-scheduler Executor to exit > (for > > > one > > > > > > day), > > > > > > > but some thread in that Executor is doing Rebalance job which > > need > > > to > > > > > > > aquire the controllerLock, then the broker is in DEAD LOCK and > > will > > > > be > > > > > > > totally lost from zookeeper for ONE DAY if I'm corrected? And > > since > > > > > it's > > > > > > > still hold outdated view of the cluster, it will try to try to > > > > follower > > > > > > up > > > > > > > the Leaders which maybe not actual Leader, caused the ERRORs as > > > above > > > > > > > mentioned. > > > > > > > > > > > > > > I'm using 8 Kafka brokers @0.8.2.1 with 3 Zookeeper server > > @3.4.6, > > > > all > > > > > > on > > > > > > > different host in same data center, the cluster load is about > > 200K > > > > > > messages > > > > > > > in and 30M bytes in and 80M bytes out totally. > > > > > > > > > > > > > > Does some one has the same issue? Any suggestion is > appreciated. > > > > > > > > > > > > > > > > > > > > > jstack: > > > > > > > > > > > > > > > "kafka-scheduler-0" daemon prio=10 tid=0x0000000057967800 > > > > nid=0x2994 > > > > > > > > waiting on condition [0x0000000046dac000] > > > > > > > > java.lang.Thread.State: WAITING (parking) > > > > > > > > at sun.misc.Unsafe.park(Native Method) > > > > > > > > - parking to wait for <0x00000000c2ec6418> (a > > > > > > > > java.util.concurrent.locks.ReentrantLock$NonfairSync) > > > > > > > > at > > > > > > > > > > java.util.concurrent.locks.LockSupport.park(LockSupport.java:156) > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:811) > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:842) > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1178) > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:186) > > > > > > > > at > > > > > > > > > > > > java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:262) > > > > > > > > at kafka.utils.Utils$.inLock(Utils.scala:533) > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > kafka.controller.KafkaController$$anonfun$kafka$controller$KafkaController$$checkAndTriggerPartitionRebalance$4.apply(KafkaController.scala:1131) > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > kafka.controller.KafkaController$$anonfun$kafka$controller$KafkaController$$checkAndTriggerPartitionRebalance$4.apply(KafkaController.scala:1127) > > > > > > > > at > > > > > > > > > > > > > > > scala.collection.immutable.HashMap$HashMap1.foreach(HashMap.scala:224) > > > > > > > > at > > > > > > > > > > > > > > > > > > > > scala.collection.immutable.HashMap$HashTrieMap.foreach(HashMap.scala:403) > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > kafka.controller.KafkaController.kafka$controller$KafkaController$$checkAndTriggerPartitionRebalance(KafkaController.scala:1127) > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > kafka.controller.KafkaController$$anonfun$onControllerFailover$1.apply$mcV$sp(KafkaController.scala:326) > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > kafka.utils.KafkaScheduler$$anonfun$1.apply$mcV$sp(KafkaScheduler.scala:99) > > > > > > > > at kafka.utils.Utils$$anon$1.run(Utils.scala:54) > > > > > > > > at > > > > > > > > > > > > > > > java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441) > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > java.util.concurrent.FutureTask$Sync.innerRunAndReset(FutureTask.java:317) > > > > > > > > at > > > > > > > > java.util.concurrent.FutureTask.runAndReset(FutureTask.java:150) > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$101(ScheduledThreadPoolExecutor.java:98) > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.runPeriodic(ScheduledThreadPoolExecutor.java:180) > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:204) > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) > > > > > > > > at java.lang.Thread.run(Thread.java:662) > > > > > > > > > > > > > > > "ZkClient-EventThread-15-xxxxxxxxxxxxxxxxxxxxx" daemon prio=10 > > > > > > > > tid=0x00002aaab42ba800 nid=0x24c4 waiting on condition [ > > > > > > > > 0x00000000402e8000] > > > > > > > > java.lang.Thread.State: TIMED_WAITING (parking) > > > > > > > > at sun.misc.Unsafe.park(Native Method) > > > > > > > > - parking to wait for <0x00000000f4c450b8> (a > > > > > > > > > > > > > > > java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject) > > > > > > > > at > > > > > > > > > > > > > > > java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:196) > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:2025) > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > java.util.concurrent.ThreadPoolExecutor.awaitTermination(ThreadPoolExecutor.java:1253) > > > > > > > > at > > > > > kafka.utils.KafkaScheduler.shutdown(KafkaScheduler.scala:88) > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > kafka.controller.KafkaController.onControllerResignation(KafkaController.scala:350) > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > kafka.controller.KafkaController$SessionExpirationListener$$anonfun$handleNewSession$1.apply$mcZ$sp(KafkaController.scala:1108) > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > kafka.controller.KafkaController$SessionExpirationListener$$anonfun$handleNewSession$1.apply(KafkaController.scala:1107) > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > kafka.controller.KafkaController$SessionExpirationListener$$anonfun$handleNewSession$1.apply(KafkaController.scala:1107) > > > > > > > > at kafka.utils.Utils$.inLock(Utils.scala:535) > > > > > > > > at > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > kafka.controller.KafkaController$SessionExpirationListener.handleNewSession(KafkaController.scala:1107) > > > > > > > > at > > org.I0Itec.zkclient.ZkClient$4.run(ZkClient.java:472) > > > > > > > > at > > > > > org.I0Itec.zkclient.ZkEventThread.run(ZkEventThread.java:71) > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
