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https://issues.apache.org/jira/browse/YARN-7168?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16156350#comment-16156350
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Jiandan Yang commented on YARN-7168:
-------------------------------------
Sorry, I should create this issue in Hadoop HDFS, can anyone help me move to
Hadoop HDFS project?
> The size of dataQueue and ackQueue in DataStreamer has no limit when writer
> thread is interrupted
> -------------------------------------------------------------------------------------------------
>
> Key: YARN-7168
> URL: https://issues.apache.org/jira/browse/YARN-7168
> Project: Hadoop YARN
> Issue Type: Bug
> Components: client
> Reporter: Jiandan Yang
> Attachments: mat.jpg
>
>
> In our cluster, when found NodeManager frequently FullGC when decommissioning
> NodeManager, and we found the biggest object is dataQueue of DataStreamer, it
> has almost 6w DFSPacket, and every DFSPacket is about 64k, as shown below.
> The root reason is that the size of dataQueue and ackQueue in DataStreamer
> has no limit when writer thread is interrupted.
> DFSOutputStream#waitAndQueuePacket does not wait when writer thread is
> interrupted. I know NodeManager may stop writing when interruped, but
> DFSOutputStream also could do something to avoid Infinite growth of dataQueue.
> {code:java}
> while (!streamerClosed && dataQueue.size() + ackQueue.size() >
> dfsClient.getConf().getWriteMaxPackets()) {
> if (firstWait) {
> Span span = Tracer.getCurrentSpan();
> if (span != null) {
> span.addTimelineAnnotation("dataQueue.wait");
> }
> firstWait = false;
> }
> try {
> dataQueue.wait();
> } catch (InterruptedException e) {
> // If we get interrupted while waiting to queue data, we still
> need to get rid
> // of the current packet. This is because we have an invariant
> that if
> // currentPacket gets full, it will get queued before the next
> writeChunk.
> //
> // Rather than wait around for space in the queue, we should
> instead try to
> // return to the caller as soon as possible, even though we
> slightly overrun
> // the MAX_PACKETS length.
> Thread.currentThread().interrupt();
> break;
> }
> }
> } finally {
> Span span = Tracer.getCurrentSpan();
> if ((span != null) && (!firstWait)) {
> span.addTimelineAnnotation("end.wait");
> }
> }
> {code}
> !mat.jpg|memory_analysis!
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