hi, Tianwang Li
看到有三个图片挂了，可以试着把图片上传到第三方的图床，然后贴个链接过来，另外：
> 任务经常会出现反压（特别是在窗口输出的时候）
这个检查一下窗口下游算子的情况，比如是不是窗口输出的数据过多，而 sink 的并发还和之前的保持一致，导致处理速度跟不上，从而导致的反压。
> 大部分时候checkpoint都是在1分钟内完成，偶尔会出现checkpint需要超过30分钟的（出现的频率不高，1～2天1次）
这种也可以看看是不是 HDFS 有时候压力比较大导致的出现毛刺现象
另外建议补一下 UI 上 chekcpoint 相关的截图和日志信息，这样才能更好的定位问题。
Best ！
zhisheng
Tianwang Li <litianw...@gmail.com> 于2020年6月28日周日 上午10:17写道：
> 关于Flink checkpoint偶尔会比较长时间的问题。
>
> *环境与背景：*
> 版本：flink1.10.0
> 数据量：每秒约10万左右的记录，数据源是kafka
> 计算逻辑：滑动窗口统计，每个窗口输出的规模大概1～2千万记录。
> 是否有反压：任务经常会出现反压（特别是在窗口输出的时候）。
>
> *问题：*
> 大部分时候checkpoint都是在1分钟内完成，偶尔会出现checkpint需要超过30分钟的（出现的频率不高，1～2天1次）。
> source的checkpoint消耗的时间比较长。Trigger checkpoint 到 Starting checkpoint消耗时间比较长。
>
> checkpoint情况大致如下：
>
> [image: image.png]
> [image: image.png]
> [image: image.png]
>
> 2020-06-24 21:09:53,369 DEBUG
> org.apache.flink.runtime.taskexecutor.TaskExecutor - Trigger
> checkpoint 316@1593004193363 for 84dce1ec8aa5a4df2d1758d6e9278693.
>
> 2020-06-24 21:09:58,327 DEBUG
> org.apache.flink.runtime.taskexecutor.TaskExecutor - Received
> heartbeat request from e88ea2f790430c9c160e540ef0546d60.
>
> 2020-06-24 21:09:59,266 DEBUG
> org.apache.flink.runtime.taskexecutor.TaskExecutor - Received
> heartbeat request from b93d7167db364dfdcbda886944f1482f.
>
> 2020-06-24 21:09:59,686 INFO
> org.apache.flink.runtime.taskexecutor.TaskManagerRunner
> - Memory usage stats: [HEAP: 202/2573/2573 MB, NON HEAP:
> 111/114/424 MB (used/committed/max)]
>
> 2020-06-24 21:09:59,686 INFO
> org.apache.flink.runtime.taskexecutor.TaskManagerRunner
> - Direct memory stats: Count: 17403, Total Capacity: 583911423,
> Used Memory: 583911424
>
> 2020-06-24 21:09:59,686 INFO
> org.apache.flink.runtime.taskexecutor.TaskManagerRunner
> - Off-heap pool stats: [Code Cache: 35/35/240 MB
> (used/committed/max)], [Metaspace: 67/69/96 MB (used/committed/max)],
> [Compressed Class Space: 8/9/88 MB (used/committed/max)]
>
> 2020-06-24 21:09:59,686 INFO
> org.apache.flink.runtime.taskexecutor.TaskManagerRunner
> - Garbage collector stats: [PS Scavenge, GC TIME (ms): 108643, GC
> COUNT: 6981], [PS MarkSweep, GC TIME (ms): 1074, GC COUNT: 6]
>
> 2020-06-24 21:10:08,346 DEBUG
> org.apache.flink.runtime.taskexecutor.TaskExecutor - Received
> heartbeat request from e88ea2f790430c9c160e540ef0546d60.
>
> 2020-06-24 21:10:09,286 DEBUG
> org.apache.flink.runtime.taskexecutor.TaskExecutor - Received
> heartbeat request from b93d7167db364dfdcbda886944f1482f.
>
> 2020-06-24 21:10:09,686 INFO
> org.apache.flink.runtime.taskexecutor.TaskManagerRunner
> - Memory usage stats: [HEAP: 557/2573/2573 MB, NON HEAP:
> 111/114/424 MB (used/committed/max)]
>
> 2020-06-24 21:10:09,686 INFO
> org.apache.flink.runtime.taskexecutor.TaskManagerRunner
> - Direct memory stats: Count: 17403, Total Capacity: 583911423,
> Used Memory: 583911424
>
> 2020-06-24 21:10:09,686 INFO
> org.apache.flink.runtime.taskexecutor.TaskManagerRunner
> - Off-heap pool stats: [Code Cache: 35/35/240 MB
> (used/committed/max)], [Metaspace: 67/69/96 MB (used/committed/max)],
> [Compressed Class Space: 8/9/88 MB (used/committed/max)]
>
> 2020-06-24 21:10:09,686 INFO
> org.apache.flink.runtime.taskexecutor.TaskManagerRunner
> - Garbage collector stats: [PS Scavenge, GC TIME (ms): 108643, GC
> COUNT: 6981], [PS MarkSweep, GC TIME (ms): 1074, GC COUNT: 6]
>
>
> 省略。。。。
>
>
> 2020-06-24 21:55:39,875 INFO
> org.apache.flink.runtime.taskexecutor.TaskManagerRunner
> - Direct memory stats: Count: 17403, Total Capacity: 583911423,
> Used Memory: 583911424
>
> 2020-06-24 21:55:39,875 INFO
> org.apache.flink.runtime.taskexecutor.TaskManagerRunner
> - Off-heap pool stats: [Code Cache: 35/35/240 MB
> (used/committed/max)], [Metaspace: 67/69/96 MB (used/committed/max)],
> [Compressed Class Space: 8/9/88 MB (used/committed/max)]
>
> 2020-06-24 21:55:39,876 INFO
> org.apache.flink.runtime.taskexecutor.TaskManagerRunner
> - Garbage collector stats: [PS Scavenge, GC TIME (ms): 110520, GC
> COUNT: 7083], [PS MarkSweep, GC TIME (ms): 1074, GC COUNT: 6]
>
> 2020-06-24 21:55:41,721 DEBUG
> org.apache.flink.streaming.runtime.tasks.StreamTask - Starting
> checkpoint (316) CHECKPOINT on task Source: Custom Source -> Map -> Filter
> -> Timestamps/Watermarks (4/10)
>
> 2020-06-24 21:55:41,721 DEBUG
> org.apache.flink.runtime.state.AbstractSnapshotStrategy -
> DefaultOperatorStateBackend snapshot (FsCheckpointStorageLocation
> {fileSystem=org.apache.flink.core.fs.SafetyNetWrapperFileSystem@4a4b11cd,
> checkpointDirectory=hdfs://xxxxchk-316,
> sharedStateDirectory=hdfs://xxxxshared,
> taskOwnedStateDirectory=hdfs://xxxxtaskowned,
> metadataFilePath=hdfs://xxxxchk-316/_metadata, reference=(default),
> fileStateSizeThreshold=1024, writeBufferSize=4096}, synchronous part) in
> thread Thread[Source: Custom Source -> Map -> Filter ->
> Timestamps/Watermarks (4/10),5,Flink Task Threads] took 0 ms.
>
> 2020-06-24 21:55:41,721 DEBUG
> org.apache.flink.runtime.state.AbstractSnapshotStrategy -
> DefaultOperatorStateBackend snapshot (FsCheckpointStorageLocation
> {fileSystem=org.apache.flink.core.fs.SafetyNetWrapperFileSystem@4a4b11cd,
> checkpointDirectory=hdfs://xxxxchk-316,
> sharedStateDirectory=hdfs://xxxxshared,
> taskOwnedStateDirectory=hdfs://xxxxtaskowned,
> metadataFilePath=hdfs://xxxxchk-316/_metadata, reference=(default),
> fileStateSizeThreshold=1024, writeBufferSize=4096}, synchronous part) in
> thread Thread[Source: Custom Source -> Map -> Filter ->
> Timestamps/Watermarks (4/10),5,Flink Task Threads] took 0 ms.
>
> 2020-06-24 21:55:41,721 DEBUG
> org.apache.flink.runtime.state.AbstractSnapshotStrategy -
> DefaultOperatorStateBackend snapshot (FsCheckpointStorageLocation
> {fileSystem=org.apache.flink.core.fs.SafetyNetWrapperFileSystem@4a4b11cd,
> checkpointDirectory=hdfs://xxxxchk-316,
> sharedStateDirectory=hdfs://xxxxshared,
> taskOwnedStateDirectory=hdfs://xxxxtaskowned,
> metadataFilePath=hdfs://xxxxchk-316/_metadata, reference=(default),
> fileStateSizeThreshold=1024, writeBufferSize=4096}, synchronous part) in
> thread Thread[Source: Custom Source -> Map -> Filter ->
> Timestamps/Watermarks (4/10),5,Flink Task Threads] took 0 ms.
>
> 2020-06-24 21:55:41,721 DEBUG
> org.apache.flink.runtime.state.AbstractSnapshotStrategy -
> DefaultOperatorStateBackend snapshot (FsCheckpointStorageLocation
> {fileSystem=org.apache.flink.core.fs.SafetyNetWrapperFileSystem@4a4b11cd,
> checkpointDirectory=hdfs://xxxxchk-316,
> sharedStateDirectory=hdfs://xxxxshared,
> taskOwnedStateDirectory=hdfs://xxxxtaskowned,
> metadataFilePath=hdfs://xxxxchk-316/_metadata, reference=(default),
> fileStateSizeThreshold=1024, writeBufferSize=4096}, synchronous part) in
> thread Thread[Source: Custom Source -> Map -> Filter ->
> Timestamps/Watermarks (4/10),5,Flink Task Threads] took 0 ms.
>
> 2020-06-24 21:55:41,721 DEBUG
> org.apache.flink.streaming.runtime.tasks.StreamTask - Finished
> synchronous checkpoints for checkpoint 316 on task Source: Custom Source ->
> Map -> Filter -> Timestamps/Watermarks (4/10)
>
> 2020-06-24 21:55:41,721 DEBUG
> org.apache.flink.streaming.runtime.tasks.StreamTask - Source:
> Custom Source -> Map -> Filter -> Timestamps/Watermarks (4/10) - finished
> synchronous part of checkpoint 316. Alignment duration: 0 ms, snapshot
> duration 0 ms
>
> 2020-06-24 21:55:41,737 DEBUG
> org.apache.flink.runtime.state.AbstractSnapshotStrategy -
> DefaultOperatorStateBackend snapshot (FsCheckpointStorageLocation
> {fileSystem=org.apache.flink.core.fs.SafetyNetWrapperFileSystem@4a4b11cd,
> checkpointDirectory=hdfs://xxxxchk-316,
> sharedStateDirectory=hdfs://xxxxshared,
> taskOwnedStateDirectory=hdfs://xxxxtaskowned,
> metadataFilePath=hdfs://xxxxchk-316/_metadata, reference=(default),
> fileStateSizeThreshold=1024, writeBufferSize=4096}, asynchronous part) in
> thread Thread[AsyncOperations-thread-316,5,Flink Task Threads] took 16 ms.
>
> 2020-06-24 21:55:41,738 DEBUG
> org.apache.flink.streaming.runtime.tasks.StreamTask - Source:
> Custom Source -> Map -> Filter -> Timestamps/Watermarks (4/10) - finished
> asynchronous part of checkpoint 316. Asynchronous duration: 16 ms
>
> 2020-06-24 21:55:42,008 DEBUG
> org.apache.flink.streaming.runtime.io.CheckpointBarrierAligner -
> Window(SlidingEventTimeWindows(10800000, 300000, 0), EventTimeTrigger,
> anon$11, ScalaProcessWindowFunctionWrapper) -> Map (10/10)
> (a608e8a1ab75622dc57f164bdbb86743): Received barrier from channel 3.
>
> 2020-06-24 21:55:42,008 DEBUG
> org.apache.flink.streaming.runtime.io.CheckpointBarrierAligner -
> Window(SlidingEventTimeWindows(10800000, 300000, 0), EventTimeTrigger,
> anon$11, ScalaProcessWindowFunctionWrapper) -> Map (10/10)
> (a608e8a1ab75622dc57f164bdbb86743): Starting stream alignment for
> checkpoint 316.
>
> 2020-06-24 21:55:42,110 DEBUG
> org.apache.flink.streaming.runtime.io.CheckpointBarrierAligner -
> Window(SlidingEventTimeWindows(10800000, 300000, 0), EventTimeTrigger,
> anon$11, ScalaProcessWindowFunctionWrapper) -> Map (10/10)
> (a608e8a1ab75622dc57f164bdbb86743): Received barrier from channel 7.
>
> 2020-06-24 21:55:42,110 DEBUG
> org.apache.flink.streaming.runtime.io.CheckpointBarrierAligner -
> Window(SlidingEventTimeWindows(10800000, 300000, 0), EventTimeTrigger,
> anon$11, ScalaProcessWindowFunctionWrapper) -> Map (10/10)
> (a608e8a1ab75622dc57f164bdbb86743): Received barrier from channel 2.
>
> 2020-06-24 21:55:42,110 DEBUG
> org.apache.flink.streaming.runtime.io.CheckpointBarrierAligner -
> Window(SlidingEventTimeWindows(10800000, 300000, 0), EventTimeTrigger,
> anon$11, ScalaProcessWindowFunctionWrapper) -> Map (10/10)
> (a608e8a1ab75622dc57f164bdbb86743): Received barrier from channel 8.
>
> 2020-06-24 21:55:42,110 DEBUG
> org.apache.flink.streaming.runtime.io.CheckpointBarrierAligner -
> Window(SlidingEventTimeWindows(10800000, 300000, 0), EventTimeTrigger,
> anon$11, ScalaProcessWindowFunctionWrapper) -> Map (10/10)
> (a608e8a1ab75622dc57f164bdbb86743): Received barrier from channel 6.
>
> 2020-06-24 21:55:42,110 DEBUG
> org.apache.flink.streaming.runtime.io.CheckpointBarrierAligner -
> Window(SlidingEventTimeWindows(10800000, 300000, 0), EventTimeTrigger,
> anon$11, ScalaProcessWindowFunctionWrapper) -> Map (10/10)
> (a608e8a1ab75622dc57f164bdbb86743): Received barrier from channel 0.
>
> 2020-06-24 21:55:42,110 DEBUG
> org.apache.flink.streaming.runtime.io.CheckpointBarrierAligner -
> Window(SlidingEventTimeWindows(10800000, 300000, 0), EventTimeTrigger,
> anon$11, ScalaProcessWindowFunctionWrapper) -> Map (10/10)
> (a608e8a1ab75622dc57f164bdbb86743): Received barrier from channel 5.
>
> 2020-06-24 21:55:42,110 DEBUG
> org.apache.flink.streaming.runtime.io.CheckpointBarrierAligner -
> Window(SlidingEventTimeWindows(10800000, 300000, 0), EventTimeTrigger,
> anon$11, ScalaProcessWindowFunctionWrapper) -> Map (10/10)
> (a608e8a1ab75622dc57f164bdbb86743): Received barrier from channel 9.
>
> 2020-06-24 21:55:42,110 DEBUG
> org.apache.flink.streaming.runtime.io.CheckpointBarrierAligner -
> Window(SlidingEventTimeWindows(10800000, 300000, 0), EventTimeTrigger,
> anon$11, ScalaProcessWindowFunctionWrapper) -> Map (10/10)
> (a608e8a1ab75622dc57f164bdbb86743): Received barrier from channel 4.
>
> 2020-06-24 21:55:42,110 DEBUG
> org.apache.flink.streaming.runtime.io.CheckpointBarrierAligner -
> Window(SlidingEventTimeWindows(10800000, 300000, 0), EventTimeTrigger,
> anon$11, ScalaProcessWindowFunctionWrapper) -> Map (10/10)
> (a608e8a1ab75622dc57f164bdbb86743): Received barrier from channel 1.
>
> 2020-06-24 21:55:42,110 DEBUG
> org.apache.flink.streaming.runtime.io.CheckpointBarrierAligner -
> Window(SlidingEventTimeWindows(10800000, 300000, 0), EventTimeTrigger,
> anon$11, ScalaProcessWindowFunctionWrapper) -> Map (10/10)
> (a608e8a1ab75622dc57f164bdbb86743): Received all barriers, triggering
> checkpoint 316 at 1593004193363.
>
> 2020-06-24 21:55:42,110 DEBUG
> org.apache.flink.streaming.runtime.io.CheckpointBarrierAligner -
> Window(SlidingEventTimeWindows(10800000, 300000, 0), EventTimeTrigger,
> anon$11, ScalaProcessWindowFunctionWrapper) -> Map (10/10)
> (a608e8a1ab75622dc57f164bdbb86743): End of stream alignment, feeding
> buffered data back.
>
> 2020-06-24 21:55:42,110 DEBUG
> org.apache.flink.streaming.runtime.tasks.StreamTask - Starting
> checkpoint (316) CHECKPOINT on task
> Window(SlidingEventTimeWindows(10800000, 300000, 0), EventTimeTrigger,
> anon$11, ScalaProcessWindowFunctionWrapper) -> Map (10/10)
>
> 2020-06-24 21:55:42,110 DEBUG
> org.apache.flink.runtime.state.AbstractSnapshotStrategy -
> DefaultOperatorStateBackend snapshot (FsCheckpointStorageLocation
> {fileSystem=org.apache.flink.core.fs.SafetyNetWrapperFileSystem@61164119,
> checkpointDirectory=hdfs://xxxxchk-316,
> sharedStateDirectory=hdfs://xxxxshared,
> taskOwnedStateDirectory=hdfs://xxxxtaskowned,
> metadataFilePath=hdfs://xxxxchk-316/_metadata, reference=(default),
> fileStateSizeThreshold=1024, writeBufferSize=4096}, synchronous part) in
> thread Thread[Window(SlidingEventTimeWindows(10800000, 300000, 0),
> EventTimeTrigger, anon$11, ScalaProcessWindowFunctionWrapper) -> Map
> (10/10),5,Flink Task Threads] took 0 ms.
>
> 2020-06-24 21:55:42,110 DEBUG
> org.apache.flink.runtime.state.AbstractSnapshotStrategy -
> DefaultOperatorStateBackend snapshot (FsCheckpointStorageLocation
> {fileSystem=org.apache.flink.core.fs.SafetyNetWrapperFileSystem@61164119,
> checkpointDirectory=hdfs://xxxxchk-316,
> sharedStateDirectory=hdfs://xxxxshared,
> taskOwnedStateDirectory=hdfs://xxxxtaskowned,
> metadataFilePath=hdfs://xxxxchk-316/_metadata, reference=(default),
> fileStateSizeThreshold=1024, writeBufferSize=4096}, synchronous part) in
> thread Thread[Window(SlidingEventTimeWindows(10800000, 300000, 0),
> EventTimeTrigger, anon$11, ScalaProcessWindowFunctionWrapper) -> Map
> (10/10),5,Flink Task Threads] took 0 ms.
>
> 2020-06-24 21:55:42,980 DEBUG
> org.apache.flink.runtime.state.AbstractSnapshotStrategy -
> Asynchronous incremental RocksDB snapshot (FsCheckpointStorageLocation
> {fileSystem=org.apache.flink.core.fs.SafetyNetWrapperFileSystem@61164119,
> checkpointDirectory=hdfs://xxxx/chk-316,
> sharedStateDirectory=hdfs://xxxx/shared,
> taskOwnedStateDirectory=hdfs://xxxx/taskowned,
> metadataFilePath=hdfs://xxxx/chk-316/_metadata, reference=(default),
> fileStateSizeThreshold=1024, writeBufferSize=4096}, synchronous part) in
> thread Thread[Window(SlidingEventTimeWindows(10800000, 300000, 0),
> EventTimeTrigger, anon$11, ScalaProcessWindowFunctionWrapper) -> Map
> (10/10),5,Flink Task Threads] took 870 ms.
>
> 2020-06-24 21:55:42,981 DEBUG
> org.apache.flink.streaming.runtime.tasks.StreamTask - Finished
> synchronous checkpoints for checkpoint 316 on task
> Window(SlidingEventTimeWindows(10800000, 300000, 0), EventTimeTrigger,
> anon$11, ScalaProcessWindowFunctionWrapper) -> Map (10/10)
>
> 2020-06-24 21:55:42,981 DEBUG
> org.apache.flink.streaming.runtime.tasks.StreamTask -
> Window(SlidingEventTimeWindows(10800000, 300000, 0), EventTimeTrigger,
> anon$11, ScalaProcessWindowFunctionWrapper) -> Map (10/10) - finished
> synchronous part of checkpoint 316. Alignment duration: 101 ms, snapshot
> duration 870 ms
>
> 2020-06-24 21:55:42,981 DEBUG
> org.apache.flink.streaming.runtime.io.CachedBufferStorage -
> Window(SlidingEventTimeWindows(10800000, 300000, 0), EventTimeTrigger,
> anon$11, ScalaProcessWindowFunctionWrapper) -> Map (10/10)
> (a608e8a1ab75622dc57f164bdbb86743): Size of buffered data: 98304 bytes
>
> 2020-06-24 21:55:42,981 DEBUG
> org.apache.flink.streaming.runtime.io.CachedBufferStorage -
> Window(SlidingEventTimeWindows(10800000, 300000, 0), EventTimeTrigger,
> anon$11, ScalaProcessWindowFunctionWrapper) -> Map (10/10)
> (a608e8a1ab75622dc57f164bdbb86743): Finished feeding back buffered data.
>
> 2020-06-24 21:55:43,814 DEBUG
> org.apache.flink.runtime.taskexecutor.TaskExecutor - Received
> heartbeat request from e88ea2f790430c9c160e540ef0546d60.
>
> 2020-06-24 21:55:44,758 DEBUG
> org.apache.flink.runtime.taskexecutor.TaskExecutor - Received
> heartbeat request from b93d7167db364dfdcbda886944f1482f.
>
> 2020-06-24 21:55:45,714 DEBUG
> org.apache.flink.runtime.state.AbstractSnapshotStrategy -
> Asynchronous incremental RocksDB snapshot (FsCheckpointStorageLocation
> {fileSystem=org.apache.flink.core.fs.SafetyNetWrapperFileSystem@61164119,
> checkpointDirectory=hdfs://xxxx/chk-316,
> sharedStateDirectory=hdfs://xxxx/shared,
> taskOwnedStateDirectory=hdfs://xxxx/taskowned,
> metadataFilePath=hdfs://xxxx/chk-316/_metadata, reference=(default),
> fileStateSizeThreshold=1024, writeBufferSize=4096}, asynchronous part) in
> thread Thread[AsyncOperations-thread-316,5,Flink Task Threads] took 2733 ms.
>
> 2020-06-24 21:55:45,715 DEBUG
> org.apache.flink.streaming.runtime.tasks.StreamTask -
> Window(SlidingEventTimeWindows(10800000, 300000, 0), EventTimeTrigger,
> anon$11, ScalaProcessWindowFunctionWrapper) -> Map (10/10) - finished
> asynchronous part of checkpoint 316. Asynchronous duration: 2734 ms
>
> 2020-06-24 21:55:49,876 INFO
> org.apache.flink.runtime.taskexecutor.TaskManagerRunner
> - Memory usage stats: [HEAP: 220/2589/2589 MB, NON HEAP:
> 111/114/424 MB (used/committed/max)]
>
> 2020-06-24 21:55:49,876 INFO
> org.apache.flink.runtime.taskexecutor.TaskManagerRunner
> - Direct memory stats: Count: 17414, Total Capacity: 584128352,
> Used Memory: 584128353
>
> 2020-06-24 21:55:49,876 INFO
> org.apache.flink.runtime.taskexecutor.TaskManagerRunner
> - Off-heap pool stats: [Code Cache: 35/35/240 MB
> (used/committed/max)], [Metaspace: 67/69/96 MB (used/committed/max)],
> [Compressed Class Space: 8/9/88 MB (used/committed/max)]
>
> 2020-06-24 21:55:49,876 INFO
> org.apache.flink.runtime.taskexecutor.TaskManagerRunner
> - Garbage collector stats: [PS Scavenge, GC TIME (ms): 110525, GC
> COUNT: 7084], [PS MarkSweep, GC TIME (ms): 1074, GC COUNT: 6]
>
>
> --
> **************************************
> tivanli
> **************************************
>
