19824 is an identifier that would tie it back to a specific BatchScanner
instance, but that's not going to tell you where in the code it was created.
I remember something with a finalize() method being invoked in a
try-with-resources block (the finalizer closes the BS, and then the
finally for the try-with-resources also tries to close() it). Let me see
if I can find that issue -- we might have made a code-change in 1.7.3
for it.
David Boyd wrote:
Josh:
Thanks. I am using 1.7.2. That is why I asked about how to trace back to
a specific scan in
my code. I agree this sounds like a race condition but I have multiple
batch scanners potentially happening
including some down inside Geomesa. So figuring out from the trace which
scanner spawned the thread would
be helpful to generate an snippit.
On 4/19/17 1:43 PM, Josh Elser wrote:
David --
What version of Accumulo? Can you share a snippet of code (or,
ideally, a executable example we can run) in which you're using the
BatchScanner?
Generally speaking, it appears that one of the BatchScanner threads
was finished, trying to return the Thrift connection to the pool, but
the underlying socket was already closed (assumably, by someone else).
Sounds like a race condition, multiple close()'s happening perhaps.
David Boyd wrote:
All:
I am getting this stack trace periodically based on no pattern I can
determine from my application.
Is this a message I should be worried about?
What is a technique to trace this back to my code and the cause?
Obviously something is closing things before the thread closes it.
2017-04-19 12:33:53,423 | WARN | [batch scanner 19824- 8 looking up 1
ranges at accumulodev:9997] | (TIOStreamTransport.java:112) - Error
closing output stream.
java.io.IOException: The stream is closed
at
org.apache.hadoop.net.SocketOutputStream.write(SocketOutputStream.java:118)
at
java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82)
at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140)
at java.io.FilterOutputStream.close(FilterOutputStream.java:158)
at
org.apache.thrift.transport.TIOStreamTransport.close(TIOStreamTransport.java:110)
at
org.apache.thrift.transport.TFramedTransport.close(TFramedTransport.java:89)
at
org.apache.accumulo.core.client.impl.ThriftTransportPool$CachedTTransport.close(ThriftTransportPool.java:309)
at
org.apache.accumulo.core.client.impl.ThriftTransportPool.returnTransport(ThriftTransportPool.java:571)
at
org.apache.accumulo.core.rpc.ThriftUtil.returnClient(ThriftUtil.java:151)
at
org.apache.accumulo.core.client.impl.TabletServerBatchReaderIterator.doLookup(TabletServerBatchReaderIterator.java:686)
at
org.apache.accumulo.core.client.impl.TabletServerBatchReaderIterator$QueryTask.run(TabletServerBatchReaderIterator.java:349)
at org.apache.htrace.wrappers.TraceRunnable.run(TraceRunnable.java:57)
at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at
org.apache.accumulo.fate.util.LoggingRunnable.run(LoggingRunnable.java:35)
at java.lang.Thread.run(Thread.java:745)
