[FLINK-12544] Deadlock while releasing memory and requesting segment concurrent in SpillableSubpartition

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.8.1
• Component/s: Runtime / Network
• Labels: pull-request-available
• Assignee: Zhijiang
• Reporter: Zhijiang
• Created: 17/May/19 10:44
• Updated: 06/Jun/19 09:14
• Resolved: 04/Jun/19 13:25

Description

It is reported by flink user, and the original jstack is as following:

 

// "CoGroup (2/2)":
                at org.apache.flink.runtime.io.network.NetworkEnvironment.registerTask(NetworkEnvironment.java:213)
                - waiting to lock <0x000000062bf859b8> (a java.lang.Object)
                at org.apache.flink.runtime.taskmanager.Task.run(Task.java:614)
                at java.lang.Thread.run(Thread.java:745)
"CoGroup (1/2)":
                at org.apache.flink.runtime.io.network.buffer.LocalBufferPool.recycle(LocalBufferPool.java:277)
                - waiting to lock <0x000000063fdf4888> (a java.util.ArrayDeque)
                at org.apache.flink.runtime.io.network.buffer.NetworkBuffer.deallocate(NetworkBuffer.java:172)
                at org.apache.flink.shaded.netty4.io.netty.buffer.AbstractReferenceCountedByteBuf.release0(AbstractReferenceCountedByteBuf.java:95)
                at org.apache.flink.shaded.netty4.io.netty.buffer.AbstractReferenceCountedByteBuf.release(AbstractReferenceCountedByteBuf.java:84)
                at org.apache.flink.runtime.io.network.buffer.NetworkBuffer.recycleBuffer(NetworkBuffer.java:147)
                at org.apache.flink.runtime.io.network.buffer.BufferConsumer.close(BufferConsumer.java:121)
                at org.apache.flink.runtime.io.network.partition.SpillableSubpartition.spillFinishedBufferConsumers(SpillableSubpartition.java:274)
                at org.apache.flink.runtime.io.network.partition.SpillableSubpartition.releaseMemory(SpillableSubpartition.java:239)
                - locked <0x000000063fdf4ac8> (a java.util.ArrayDeque)
                at org.apache.flink.runtime.io.network.partition.ResultPartition.releaseMemory(ResultPartition.java:371)
                at org.apache.flink.runtime.io.network.buffer.LocalBufferPool.setNumBuffers(LocalBufferPool.java:375)
                at org.apache.flink.runtime.io.network.buffer.NetworkBufferPool.redistributeBuffers(NetworkBufferPool.java:408)
                at org.apache.flink.runtime.io.network.buffer.NetworkBufferPool.createBufferPool(NetworkBufferPool.java:297)
                - locked <0x000000063c785350> (a java.lang.Object)
                at org.apache.flink.runtime.io.network.buffer.NetworkBufferPool.createBufferPool(NetworkBufferPool.java:259)
                at org.apache.flink.runtime.io.network.NetworkEnvironment.setupInputGate(NetworkEnvironment.java:272)
                at org.apache.flink.runtime.io.network.NetworkEnvironment.registerTask(NetworkEnvironment.java:224)
                - locked <0x000000062bf859b8> (a java.lang.Object)
                at org.apache.flink.runtime.taskmanager.Task.run(Task.java:614)
                at java.lang.Thread.run(Thread.java:745)
"DataSource  (1/1)":
                at org.apache.flink.runtime.io.network.partition.SpillableSubpartition.releaseMemory(SpillableSubpartition.java:227)
                - waiting to lock <0x000000063fdf4ac8> (a java.util.ArrayDeque)
                at org.apache.flink.runtime.io.network.partition.ResultPartition.releaseMemory(ResultPartition.java:371)
                at org.apache.flink.runtime.io.network.buffer.LocalBufferPool.requestMemorySegment(LocalBufferPool.java:257)
                - locked <0x000000063fdf4888> (a java.util.ArrayDeque)
                at org.apache.flink.runtime.io.network.buffer.LocalBufferPool.requestBufferBuilderBlocking(LocalBufferPool.java:218)
                at org.apache.flink.runtime.io.network.api.writer.RecordWriter.requestNewBufferBuilder(RecordWriter.java:213)
                at org.apache.flink.runtime.io.network.api.writer.RecordWriter.sendToTarget(RecordWriter.java:144)
                at org.apache.flink.runtime.io.network.api.writer.RecordWriter.emit(RecordWriter.java:107)
                at org.apache.flink.runtime.operators.shipping.OutputCollector.collect(OutputCollector.java:65)
                at org.apache.flink.runtime.operators.util.metrics.CountingCollector.collect(CountingCollector.java:35)
                at org.apache.flink.runtime.operators.DataSourceTask.invoke(DataSourceTask.java:193)
                at org.apache.flink.runtime.taskmanager.Task.run(Task.java:711)
                at java.lang.Thread.run(Thread.java:745)

Based on the above stack, it happens in the following scenario:

• taskA: emit -> requestBufferBuilder -> synchronized in LocalBufferPool -> SpillableSubpartition#releaseMemory -> wait for  synchronized in  SpillableSubpartition
• submit TaskB:  trigger taskA releaseMemory ->  SpillableSubpartition#releaseMemory ->  synchronized in  SpillableSubpartition ->  SpillableSubpartition#spillFinishedBufferConsumers -> bufferConsumer#close -> LocalBufferPool#recycle -> wait for synchronized in LocalBufferPool

 

Issue Links

• causes: FLINK-12740 SpillableSubpartitionTest deadlocks on Travis
• links to: GitHub Pull Request #8557