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https://issues.apache.org/jira/browse/KAFKA-5099?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15999250#comment-15999250
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Onur Karaman commented on KAFKA-5099:
-------------------------------------
I ran the file descriptor experiment against both my patch as well as against
git hash b611cfa5c0f4941a491781424afd9b699bdb894e (the commit before KIP-101:
0baea2ac13532981f3fea11e5dfc6da5aafaeaa8) several times now.
I've now witnessed file descriptor reclamation for my patch take as little as 4
minutes and as much as unbounded (I eventually gave up waiting after 20
minutes). I've only ever witnessed file descriptor reclamation for
b611cfa5c0f4941a491781424afd9b699bdb894e be unbounded (I eventually gave up
waiting after 20 minutes).
Not sure what to make of this. b611cfa5c0f4941a491781424afd9b699bdb894e is more
recent than the fix for KAFKA-4614 (5fc530bc483db145e0cba3b63a57d6d6a7c547f2).
I'm just going to submit the PR.
> Replica Deletion Regression from KIP-101
> ----------------------------------------
>
> Key: KAFKA-5099
> URL: https://issues.apache.org/jira/browse/KAFKA-5099
> Project: Kafka
> Issue Type: Bug
> Reporter: Onur Karaman
> Assignee: Onur Karaman
> Priority: Blocker
> Fix For: 0.11.0.0
>
>
> It appears that replica deletion regressed from KIP-101. Replica deletion
> happens when a broker receives a StopReplicaRequest with delete=true. Ever
> since KAFKA-1911, replica deletion has been async, meaning the broker
> responds with a StopReplicaResponse simply after marking the replica
> directory as staged for deletion. This marking happens by moving a data log
> directory and its contents such as /tmp/kafka-logs1/t1-0 to a marked
> directory like /tmp/kafka-logs1/t1-0.8c9c4c0c61c44cc59ebeb00075a2a07f-delete,
> acting as a soft-delete. A scheduled thread later actually deletes the data.
> It appears that the regression occurs while the scheduled thread is actually
> trying to delete the data, which means the controller considers operations
> such as partition reassignment and topic deletion complete. But if you look
> at the log4j logs and data logs, you'll find that the soft-deleted data logs
> haven't actually won't get deleted. It seems that restarting the broker
> actually allows for the soft-deleted directories to get deleted.
> Here's the setup:
> {code}
> > ./bin/zookeeper-server-start.sh config/zookeeper.properties
> > export LOG_DIR=logs0 && ./bin/kafka-server-start.sh
> > config/server0.properties
> > export LOG_DIR=logs1 && ./bin/kafka-server-start.sh
> > config/server1.properties
> > ./bin/kafka-topics.sh --zookeeper localhost:2181 --create --topic t0
> > --replica-assignment 1:0
> > ./bin/kafka-topics.sh --zookeeper localhost:2181 --create --topic t1
> > --replica-assignment 1:0
> > ./bin/kafka-topics.sh --zookeeper localhost:2181 --delete --topic t0
> > cat p.txt
> {"partitions":
> [
> {"topic": "t1", "partition": 0, "replicas": [0] }
> ],
> "version":1
> }
> > ./bin/kafka-reassign-partitions.sh --zookeeper localhost:2181
> > --reassignment-json-file p.txt --execute
> {code}
> Here are sample logs:
> {code}
> [2017-04-20 17:46:54,801] INFO [ReplicaFetcherManager on broker 1] Removed
> fetcher for partitions t0-0 (kafka.server.ReplicaFetcherManager)
> [2017-04-20 17:46:54,814] INFO Log for partition t0-0 is renamed to
> /tmp/kafka-logs1/t0-0.bbc8fa126e3e4ff787f6b68d158ab771-delete and is
> scheduled for deletion (kafka.log.LogManager)
> [2017-04-20 17:47:27,585] INFO Deleting index
> /tmp/kafka-logs1/t0-0.bbc8fa126e3e4ff787f6b68d158ab771-delete/00000000000000000000.index
> (kafka.log.OffsetIndex)
> [2017-04-20 17:47:27,586] INFO Deleting index
> /tmp/kafka-logs1/t0-0/00000000000000000000.timeindex (kafka.log.TimeIndex)
> [2017-04-20 17:47:27,587] ERROR Exception in deleting
> Log(/tmp/kafka-logs1/t0-0.bbc8fa126e3e4ff787f6b68d158ab771-delete). Moving it
> to the end of the queue. (kafka.log.LogManager)
> java.io.FileNotFoundException:
> /tmp/kafka-logs1/t0-0/leader-epoch-checkpoint.tmp (No such file or directory)
> at java.io.FileOutputStream.open0(Native Method)
> at java.io.FileOutputStream.open(FileOutputStream.java:270)
> at java.io.FileOutputStream.<init>(FileOutputStream.java:213)
> at java.io.FileOutputStream.<init>(FileOutputStream.java:162)
> at kafka.server.checkpoints.CheckpointFile.write(CheckpointFile.scala:41)
> at
> kafka.server.checkpoints.LeaderEpochCheckpointFile.write(LeaderEpochCheckpointFile.scala:61)
> at
> kafka.server.epoch.LeaderEpochFileCache.kafka$server$epoch$LeaderEpochFileCache$$flush(LeaderEpochFileCache.scala:178)
> at
> kafka.server.epoch.LeaderEpochFileCache$$anonfun$clear$1.apply$mcV$sp(LeaderEpochFileCache.scala:161)
> at
> kafka.server.epoch.LeaderEpochFileCache$$anonfun$clear$1.apply(LeaderEpochFileCache.scala:159)
> at
> kafka.server.epoch.LeaderEpochFileCache$$anonfun$clear$1.apply(LeaderEpochFileCache.scala:159)
> at kafka.utils.CoreUtils$.inLock(CoreUtils.scala:213)
> at kafka.utils.CoreUtils$.inWriteLock(CoreUtils.scala:221)
> at
> kafka.server.epoch.LeaderEpochFileCache.clear(LeaderEpochFileCache.scala:159)
> at kafka.log.Log.delete(Log.scala:1051)
> at
> kafka.log.LogManager.kafka$log$LogManager$$deleteLogs(LogManager.scala:442)
> at
> kafka.log.LogManager$$anonfun$startup$5.apply$mcV$sp(LogManager.scala:241)
> at
> kafka.utils.KafkaScheduler$$anonfun$1.apply$mcV$sp(KafkaScheduler.scala:110)
> at kafka.utils.CoreUtils$$anon$1.run(CoreUtils.scala:57)
> at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
> at
> java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
> at
> java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
> at
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> at java.lang.Thread.run(Thread.java:748)
> {code}
> The same appears on broker 1 for t1-0 after partition reassignment moves the
> replica off broker 1.
> Here's what the data logs show:
> {code}
> > l /tmp/kafka-logs*/t*
> /tmp/kafka-logs0/t0-0.166137ca8c28475d8c9fbf6f423a937e-delete:
> total 0
> -rw-r--r-- 1 okaraman wheel 0 Apr 20 17:46 00000000000000000000.timeindex
> -rw-r--r-- 1 okaraman wheel 0 Apr 20 17:46 leader-epoch-checkpoint
> drwxr-xr-x 2 okaraman wheel 68 Apr 20 17:46 pid-mapping
> /tmp/kafka-logs0/t1-0:
> total 40960
> -rw-r--r-- 1 okaraman wheel 10485760 Apr 20 17:46
> 00000000000000000000.index
> -rw-r--r-- 1 okaraman wheel 0 Apr 20 17:46 00000000000000000000.log
> -rw-r--r-- 1 okaraman wheel 10485756 Apr 20 17:46
> 00000000000000000000.timeindex
> -rw-r--r-- 1 okaraman wheel 0 Apr 20 17:46 leader-epoch-checkpoint
> drwxr-xr-x 2 okaraman wheel 68 Apr 20 17:46 pid-mapping
> /tmp/kafka-logs1/t0-0.bbc8fa126e3e4ff787f6b68d158ab771-delete:
> total 0
> -rw-r--r-- 1 okaraman wheel 0 Apr 20 17:46 00000000000000000000.timeindex
> -rw-r--r-- 1 okaraman wheel 0 Apr 20 17:46 leader-epoch-checkpoint
> drwxr-xr-x 2 okaraman wheel 68 Apr 20 17:46 pid-mapping
> /tmp/kafka-logs1/t1-0.8c9c4c0c61c44cc59ebeb00075a2a07f-delete:
> total 0
> -rw-r--r-- 1 okaraman wheel 0 Apr 20 17:48 00000000000000000000.timeindex
> -rw-r--r-- 1 okaraman wheel 0 Apr 20 17:46 leader-epoch-checkpoint
> drwxr-xr-x 2 okaraman wheel 68 Apr 20 17:46 pid-mapping
> {code}
> I ran the above test on the checkin preceding KIP-101 and it worked just fine.
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