[FLINK-4341] Kinesis connector does not emit maximum watermark properly

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 1.1.0, 1.1.1
• Fix Version/s: 1.1.2, 1.2.0
• Component/s: Connectors / Common
• Assignee: Tzu-Li (Gordon) Tai
• Reporter: Scott Kidder
• Created: 09/Aug/16 20:20
• Updated: 04/Nov/16 12:30
• Resolved: 29/Aug/16 09:49

Description

*Prevously reported as "Checkpoint state size grows unbounded when task parallelism not uniform"*

This issue was first encountered with Flink release 1.1.0 (commit 45f7825). I was previously using a 1.1.0 snapshot (commit 18995c8) which performed as expected. This issue was introduced somewhere between those commits.

I've got a Flink application that uses the Kinesis Stream Consumer to read from a Kinesis stream with 2 shards. I've got 2 task managers with 2 slots each, providing a total of 4 slots. When running the application with a parallelism of 4, the Kinesis consumer uses 2 slots (one per Kinesis shard) and 4 slots for subsequent tasks that process the Kinesis stream data. I use an in-memory store for checkpoint data.

Yesterday I upgraded to Flink 1.1.0 (45f7825) and noticed that checkpoint states were growing unbounded when running with a parallelism of 4, checkpoint interval of 10 seconds:

ID  State Size
1   11.3 MB
2    20.9 MB
3   30.6 MB
4   41.4 MB
5   52.6 MB
6   62.5 MB
7   71.5 MB
8   83.3 MB
9   93.5 MB

The first 4 checkpoints generally succeed, but then fail with an exception like the following:

java.lang.RuntimeException: Error triggering a checkpoint as the result of receiving checkpoint barrier at org.apache.flink.streaming.runtime.tasks.StreamTask$2.onEvent(StreamTask.java:768)
  at org.apache.flink.streaming.runtime.tasks.StreamTask$2.onEvent(StreamTask.java:758)
  at org.apache.flink.streaming.runtime.io.BarrierBuffer.processBarrier(BarrierBuffer.java:203)
  at org.apache.flink.streaming.runtime.io.BarrierBuffer.getNextNonBlocked(BarrierBuffer.java:129)
  at org.apache.flink.streaming.runtime.io.StreamInputProcessor.processInput(StreamInputProcessor.java:183)
  at org.apache.flink.streaming.runtime.tasks.OneInputStreamTask.run(OneInputStreamTask.java:66)
  at org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:266)
  at org.apache.flink.runtime.taskmanager.Task.run(Task.java:584)
  at java.lang.Thread.run(Thread.java:745)
Caused by: java.io.IOException: Size of the state is larger than the maximum permitted memory-backed state. Size=12105407 , maxSize=5242880 . Consider using a different state backend, like the File System State backend.
  at org.apache.flink.runtime.state.memory.MemoryStateBackend.checkSize(MemoryStateBackend.java:146)
  at org.apache.flink.runtime.state.memory.MemoryStateBackend$MemoryCheckpointOutputStream.closeAndGetBytes(MemoryStateBackend.java:200)
  at org.apache.flink.runtime.state.memory.MemoryStateBackend$MemoryCheckpointOutputStream.closeAndGetHandle(MemoryStateBackend.java:190)
  at org.apache.flink.runtime.state.AbstractStateBackend$CheckpointStateOutputView.closeAndGetHandle(AbstractStateBackend.java:447)
  at org.apache.flink.streaming.runtime.operators.windowing.WindowOperator.snapshotOperatorState(WindowOperator.java:879)
  at org.apache.flink.streaming.runtime.tasks.StreamTask.performCheckpoint(StreamTask.java:598)
  at org.apache.flink.streaming.runtime.tasks.StreamTask$2.onEvent(StreamTask.java:762)
  ... 8 more

Or:

2016-08-09 17:44:43,626 INFO  org.apache.flink.streaming.runtime.tasks.StreamTask           - Restoring checkpointed state to task Fold: property_id, player -> 10-minute Sliding-Window Percentile Aggregation -> Sink: InfluxDB (2/4)
2016-08-09 17:44:51,236 ERROR akka.remote.EndpointWriter            - Transient association error (association remains live) akka.remote.OversizedPayloadException: Discarding oversized payload sent to Actor[akka.tcp://flink@10.55.2.212:6123/user/jobmanager#510517238]: max allowed size 10485760 bytes, actual size of encoded class org.apache.flink.runtime.messages.checkpoint.AcknowledgeCheckpoint was 10891825 bytes.

This can be fixed by simply submitting the job with a parallelism of 2. I suspect there was a regression introduced relating to assumptions about the number of sub-tasks associated with a job stage (e.g. assuming 4 instead of a value ranging from 1-4). This is currently preventing me from using all available Task Manager slots.

Issue Links

• relates to: FLINK-5017 Introduce StreamStatus stream element to allow for temporarily idle streaming sources
• links to: GitHub Pull Request #2414