Re: Re:Re: flink savepoint问题

2020-03-30 文章 Yun Tang 
Hi

首先，如果这个问题很容易复现的话，我们需要定位到是什么导致了OOMkilled。

  1.  打开block-cache usage [1] 观察metrics中block cache的使用量。
  2.  麻烦回答一下几个问题，有助于进一步定位
 *   单个TM有几个slot
 *   单个TM的managed memory配置了多少
 *   一共声明了多少个keyed  state，（如果使用了window，也相当于会使用一个state），其中有多少个map 
state，是否经常遍历那个map state
 *   被kill的container内一共有几个rocksDB 实例，可以通过搜索日志 "Obtained shared RocksDB 
cache of size" 计数
 *   是否对RocksDB单独配置了options factory或者相关options

state.backend.rocksdb.memory.managed 
这个参数的语义是RocksDB使用的内存从Flink来，一个slot内的若干RocksDB实例会共享一块share 
cache。如果将这个参数设置为false，那么就回退到1.9以前的场景，rocksDB的内存将完全不由Flink管理，在某种程度上来说，更容易被conatiner
 kill。

如果想要快速缓解这个问题，一种办法是增大 taskmanager.memory.task.off-heap.size 
[2]，使得提供多一部分内存以供RocksDB超用。其他的缓解办法需要根据您对上面问题的回答来实施

[1] 
https://ci.apache.org/projects/flink/flink-docs-release-1.10/ops/config.html#state-backend-rocksdb-metrics-block-cache-usage
[2] 
https://ci.apache.org/projects/flink/flink-docs-stable/ops/config.html#taskmanager-memory-task-off-heap-size

Best
唐云


From: xyq 
Sent: Monday, March 30, 2020 10:41
To: user-zh@flink.apache.org 
Subject: Re:Re: flink savepoint问题

Hi，您好：
我这边有个小流 left join大流的需求，小流的数据夜间基本没有 
可能会4-5个小时没数据，目前的情况是一到晚上container老是被kill掉，报的是内存溢出。我想问下，我想把托管内存这设置成false，会有什么弊端吗？或者该问题怎么解决？困扰了好久了，请您指点一谢谢。
state.backend.rocksdb.memory.managed : false

















在 2020-03-28 11:04:09，"Congxian Qiu"  写道：
>Hi
>
>对于问题 1 在反压的情况下，可能导致 Savepoint 做不成功从而超时，这个暂时没法解决，现在有一个 issue[1] 在做 Unalign
>Checkpoint 可以解决反压情况下的 checkpoint
>对于问题 3，checkpoint 超时了，超时的定义：在设置的时间内（比如你这里 5 分钟），有 task 没有完成
>snapshot。调长超时时间能够一定的缓解这个问题，不过你最好找到超时的原因，然后针对性的优化。
>[1] https://issues.apache.org/jira/browse/FLINK-14551
>Best,
>Congxian
>
>
>大数据开发面试_夏永权  于2020年3月27日周五 下午4:19写道：
>
>> Hi，您好，在使用flink的过程中遇到如下问题，个人未能解决，所以请求您指导一下，谢谢！
>>
>> 1. flink cancel -s $SAVEPOINT_DIR $job_id -yid $application_id
>> 在程序有背压的时候停不掉
>>
>>
>>  The program finished with the following exception:
>> org.apache.flink.util.FlinkException: Could not cancel job
>> 1f768e4ca9ad5792a4844a5d12163b73.
>> at
>> org.apache.flink.client.cli.CliFrontend.lambda$cancel$6(CliFrontend.java:523)
>> at
>> org.apache.flink.client.cli.CliFrontend.runClusterAction(CliFrontend.java:843)
>> at org.apache.flink.client.cli.CliFrontend.cancel(CliFrontend.java:515)
>> at
>> org.apache.flink.client.cli.CliFrontend.parseParameters(CliFrontend.java:904)
>> at
>> org.apache.flink.client.cli.CliFrontend.lambda$main$10(CliFrontend.java:968)
>> at java.security.AccessController.doPrivileged(Native Method)
>> at javax.security.auth.Subject.doAs(Subject.java:422)
>> at
>> org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1692)
>> at
>> org.apache.flink.runtime.security.HadoopSecurityContext.runSecured(HadoopSecurityContext.java:41)
>> at org.apache.flink.client.cli.CliFrontend.main(CliFrontend.java:968)
>> Caused by: java.util.concurrent.TimeoutException
>> at
>> java.util.concurrent.CompletableFuture.timedGet(CompletableFuture.java:1771)
>> at java.util.concurrent.CompletableFuture.get(CompletableFuture.java:1915)
>> at
>> org.apache.flink.client.cli.CliFrontend.lambda$cancel$6(CliFrontend.java:521)
>> ... 9 more
>> stop flink job failed!!!
>>
>>
>>
>>
>> 2.再用flink
>> sql的ddl时候增加一个字段后，程序启动失败，需要删除savepoint才能启动(ddl后双流join的逻辑，其中一个流加了一个字段)
>>
>>
>>  The program finished with the following exception:
>> org.apache.flink.client.program.ProgramInvocationException: The main
>> method caused an error:
>> org.apache.flink.runtime.concurrent.FutureUtils$RetryException: Could not
>> complete the operation. Number of retries has been exhausted.
>> at
>> org.apache.flink.client.program.PackagedProgram.callMainMethod(PackagedProgram.java:335)
>> at
>> org.apache.flink.client.program.PackagedProgram.invokeInteractiveModeForExecution(PackagedProgram.java:205)
>> at org.apache.flink.client.ClientUtils.executeProgram(ClientUtils.java:138)
>> at
>> org.apache.flink.client.cli.CliFrontend.executeProgram(CliFrontend.java:664)
>> at org.apache.flink.client.cli.CliFrontend.run(CliFrontend.java:213)
>> at
>> org.apache.flink.client.cli.CliFrontend.parseParameters(CliFrontend.java:895)
>> at
>> org.apache.flink.client.cli.CliFrontend.lambda$main$10(CliFrontend.java:968)
>> at java.security.AccessController.doPrivileged(Native Method)
>> at javax.security.auth.Subject.doAs(Subject.java:422)
>> at
>> org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1692)
>> at
>> org.apache.flink.runtime.security.HadoopSecurityContext.runSecured(HadoopSecurityContex

Re:Re: flink savepoint问题

2020-03-29 文章 xyq 
Hi，您好：
我这边有个小流 left join大流的需求，小流的数据夜间基本没有 
可能会4-5个小时没数据，目前的情况是一到晚上container老是被kill掉，报的是内存溢出。我想问下，我想把托管内存这设置成false，会有什么弊端吗？或者该问题怎么解决？困扰了好久了，请您指点一谢谢。
state.backend.rocksdb.memory.managed : false

















在 2020-03-28 11:04:09，"Congxian Qiu"  写道：
>Hi
>
>对于问题 1 在反压的情况下，可能导致 Savepoint 做不成功从而超时，这个暂时没法解决，现在有一个 issue[1] 在做 Unalign
>Checkpoint 可以解决反压情况下的 checkpoint
>对于问题 3，checkpoint 超时了，超时的定义：在设置的时间内（比如你这里 5 分钟），有 task 没有完成
>snapshot。调长超时时间能够一定的缓解这个问题，不过你最好找到超时的原因，然后针对性的优化。
>[1] https://issues.apache.org/jira/browse/FLINK-14551
>Best,
>Congxian
>
>
>大数据开发面试_夏永权  于2020年3月27日周五 下午4:19写道：
>
>> Hi，您好，在使用flink的过程中遇到如下问题，个人未能解决，所以请求您指导一下，谢谢！
>>
>> 1. flink cancel -s $SAVEPOINT_DIR $job_id -yid $application_id
>> 在程序有背压的时候停不掉
>>
>>
>>  The program finished with the following exception:
>> org.apache.flink.util.FlinkException: Could not cancel job
>> 1f768e4ca9ad5792a4844a5d12163b73.
>> at
>> org.apache.flink.client.cli.CliFrontend.lambda$cancel$6(CliFrontend.java:523)
>> at
>> org.apache.flink.client.cli.CliFrontend.runClusterAction(CliFrontend.java:843)
>> at org.apache.flink.client.cli.CliFrontend.cancel(CliFrontend.java:515)
>> at
>> org.apache.flink.client.cli.CliFrontend.parseParameters(CliFrontend.java:904)
>> at
>> org.apache.flink.client.cli.CliFrontend.lambda$main$10(CliFrontend.java:968)
>> at java.security.AccessController.doPrivileged(Native Method)
>> at javax.security.auth.Subject.doAs(Subject.java:422)
>> at
>> org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1692)
>> at
>> org.apache.flink.runtime.security.HadoopSecurityContext.runSecured(HadoopSecurityContext.java:41)
>> at org.apache.flink.client.cli.CliFrontend.main(CliFrontend.java:968)
>> Caused by: java.util.concurrent.TimeoutException
>> at
>> java.util.concurrent.CompletableFuture.timedGet(CompletableFuture.java:1771)
>> at java.util.concurrent.CompletableFuture.get(CompletableFuture.java:1915)
>> at
>> org.apache.flink.client.cli.CliFrontend.lambda$cancel$6(CliFrontend.java:521)
>> ... 9 more
>> stop flink job failed!!!
>>
>>
>>
>>
>> 2.再用flink
>> sql的ddl时候增加一个字段后，程序启动失败，需要删除savepoint才能启动(ddl后双流join的逻辑，其中一个流加了一个字段)
>>
>>
>>  The program finished with the following exception:
>> org.apache.flink.client.program.ProgramInvocationException: The main
>> method caused an error:
>> org.apache.flink.runtime.concurrent.FutureUtils$RetryException: Could not
>> complete the operation. Number of retries has been exhausted.
>> at
>> org.apache.flink.client.program.PackagedProgram.callMainMethod(PackagedProgram.java:335)
>> at
>> org.apache.flink.client.program.PackagedProgram.invokeInteractiveModeForExecution(PackagedProgram.java:205)
>> at org.apache.flink.client.ClientUtils.executeProgram(ClientUtils.java:138)
>> at
>> org.apache.flink.client.cli.CliFrontend.executeProgram(CliFrontend.java:664)
>> at org.apache.flink.client.cli.CliFrontend.run(CliFrontend.java:213)
>> at
>> org.apache.flink.client.cli.CliFrontend.parseParameters(CliFrontend.java:895)
>> at
>> org.apache.flink.client.cli.CliFrontend.lambda$main$10(CliFrontend.java:968)
>> at java.security.AccessController.doPrivileged(Native Method)
>> at javax.security.auth.Subject.doAs(Subject.java:422)
>> at
>> org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1692)
>> at
>> org.apache.flink.runtime.security.HadoopSecurityContext.runSecured(HadoopSecurityContext.java:41)
>> at org.apache.flink.client.cli.CliFrontend.main(CliFrontend.java:968)
>> Caused by: java.util.concurrent.ExecutionException:
>> org.apache.flink.runtime.concurrent.FutureUtils$RetryException: Could not
>> complete the operation. Number of retries has been exhausted.
>> at
>> java.util.concurrent.CompletableFuture.reportGet(CompletableFuture.java:357)
>> at java.util.concurrent.CompletableFuture.get(CompletableFuture.java:1895)
>> at
>> org.apache.flink.streaming.api.environment.StreamContextEnvironment.execute(StreamContextEnvironment.java:83)
>> at
>> org.apache.flink.streaming.api.environment.StreamExecutionEnvironment.execute(StreamExecutionEnvironment.java:1620)
>> at
>> com.etl.DwdBaseCarlifeTIotBindGeoManage.main(DwdBaseCarlifeTIotBindGeoManage.java:265)
>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>> at
>> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
>> at
>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
>> at java.lang.reflect.Method.invoke(Method.java:498)
>> at
>> org.apache.flink.client.program.PackagedProgram.callMainMethod(PackagedProgram.java:321)
>> ... 11 more
>> Caused by: org.apache.flink.runtime.concurrent.FutureUtils$RetryException:
>> Could not complete the operation. Number of retries has been exhausted.
>> at
>> org.apache.flink.runtime.concurrent.FutureUtils.lambda$retryOperationWithDelay$8(FutureUtils.java:284)
>> at
>> java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:760)
>> at
>>

Re:Re: flink savepoint问题

2020-03-29 文章 xyq 
非常感谢
在 2020-03-28 11:04:09，"Congxian Qiu"  写道：
>Hi
>
>对于问题 1 在反压的情况下，可能导致 Savepoint 做不成功从而超时，这个暂时没法解决，现在有一个 issue[1] 在做 Unalign
>Checkpoint 可以解决反压情况下的 checkpoint
>对于问题 3，checkpoint 超时了，超时的定义：在设置的时间内（比如你这里 5 分钟），有 task 没有完成
>snapshot。调长超时时间能够一定的缓解这个问题，不过你最好找到超时的原因，然后针对性的优化。
>[1] https://issues.apache.org/jira/browse/FLINK-14551
>Best,
>Congxian
>
>
>大数据开发面试_夏永权  于2020年3月27日周五 下午4:19写道：
>
>> Hi，您好，在使用flink的过程中遇到如下问题，个人未能解决，所以请求您指导一下，谢谢！
>>
>> 1. flink cancel -s $SAVEPOINT_DIR $job_id -yid $application_id
>> 在程序有背压的时候停不掉
>>
>>
>>  The program finished with the following exception:
>> org.apache.flink.util.FlinkException: Could not cancel job
>> 1f768e4ca9ad5792a4844a5d12163b73.
>> at
>> org.apache.flink.client.cli.CliFrontend.lambda$cancel$6(CliFrontend.java:523)
>> at
>> org.apache.flink.client.cli.CliFrontend.runClusterAction(CliFrontend.java:843)
>> at org.apache.flink.client.cli.CliFrontend.cancel(CliFrontend.java:515)
>> at
>> org.apache.flink.client.cli.CliFrontend.parseParameters(CliFrontend.java:904)
>> at
>> org.apache.flink.client.cli.CliFrontend.lambda$main$10(CliFrontend.java:968)
>> at java.security.AccessController.doPrivileged(Native Method)
>> at javax.security.auth.Subject.doAs(Subject.java:422)
>> at
>> org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1692)
>> at
>> org.apache.flink.runtime.security.HadoopSecurityContext.runSecured(HadoopSecurityContext.java:41)
>> at org.apache.flink.client.cli.CliFrontend.main(CliFrontend.java:968)
>> Caused by: java.util.concurrent.TimeoutException
>> at
>> java.util.concurrent.CompletableFuture.timedGet(CompletableFuture.java:1771)
>> at java.util.concurrent.CompletableFuture.get(CompletableFuture.java:1915)
>> at
>> org.apache.flink.client.cli.CliFrontend.lambda$cancel$6(CliFrontend.java:521)
>> ... 9 more
>> stop flink job failed!!!
>>
>>
>>
>>
>> 2.再用flink
>> sql的ddl时候增加一个字段后，程序启动失败，需要删除savepoint才能启动(ddl后双流join的逻辑，其中一个流加了一个字段)
>>
>>
>>  The program finished with the following exception:
>> org.apache.flink.client.program.ProgramInvocationException: The main
>> method caused an error:
>> org.apache.flink.runtime.concurrent.FutureUtils$RetryException: Could not
>> complete the operation. Number of retries has been exhausted.
>> at
>> org.apache.flink.client.program.PackagedProgram.callMainMethod(PackagedProgram.java:335)
>> at
>> org.apache.flink.client.program.PackagedProgram.invokeInteractiveModeForExecution(PackagedProgram.java:205)
>> at org.apache.flink.client.ClientUtils.executeProgram(ClientUtils.java:138)
>> at
>> org.apache.flink.client.cli.CliFrontend.executeProgram(CliFrontend.java:664)
>> at org.apache.flink.client.cli.CliFrontend.run(CliFrontend.java:213)
>> at
>> org.apache.flink.client.cli.CliFrontend.parseParameters(CliFrontend.java:895)
>> at
>> org.apache.flink.client.cli.CliFrontend.lambda$main$10(CliFrontend.java:968)
>> at java.security.AccessController.doPrivileged(Native Method)
>> at javax.security.auth.Subject.doAs(Subject.java:422)
>> at
>> org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1692)
>> at
>> org.apache.flink.runtime.security.HadoopSecurityContext.runSecured(HadoopSecurityContext.java:41)
>> at org.apache.flink.client.cli.CliFrontend.main(CliFrontend.java:968)
>> Caused by: java.util.concurrent.ExecutionException:
>> org.apache.flink.runtime.concurrent.FutureUtils$RetryException: Could not
>> complete the operation. Number of retries has been exhausted.
>> at
>> java.util.concurrent.CompletableFuture.reportGet(CompletableFuture.java:357)
>> at java.util.concurrent.CompletableFuture.get(CompletableFuture.java:1895)
>> at
>> org.apache.flink.streaming.api.environment.StreamContextEnvironment.execute(StreamContextEnvironment.java:83)
>> at
>> org.apache.flink.streaming.api.environment.StreamExecutionEnvironment.execute(StreamExecutionEnvironment.java:1620)
>> at
>> com.etl.DwdBaseCarlifeTIotBindGeoManage.main(DwdBaseCarlifeTIotBindGeoManage.java:265)
>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>> at
>> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
>> at
>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
>> at java.lang.reflect.Method.invoke(Method.java:498)
>> at
>> org.apache.flink.client.program.PackagedProgram.callMainMethod(PackagedProgram.java:321)
>> ... 11 more
>> Caused by: org.apache.flink.runtime.concurrent.FutureUtils$RetryException:
>> Could not complete the operation. Number of retries has been exhausted.
>> at
>> org.apache.flink.runtime.concurrent.FutureUtils.lambda$retryOperationWithDelay$8(FutureUtils.java:284)
>> at
>> java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:760)
>> at
>> java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:736)
>> at
>> java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:474)
>> at
>>