Hi,
@Robert: I have uploaded all the log files that I could get my hands on to
https://www.dropbox.com/sh/l35q6979hy7mue7/AAAe1gABW59eQt6jGxA3pAYaa?dl=0. I
tried to remove all unrelated messages logged by the job itself. In
flink-root-jobmanager-0-micardo-dev.log I kept the Flink startup messages and
the last half hour before the segfault.
@Stefan: Your theory could be the key. In the stack trace I see a call to
org.apache.flink.runtime.metrics.dump.MetricDumpSerialization.serializeGauge
that results in a call to
com.micardo.backend.tail.TransitionProcessor$2.getValue()Ljava/lang/Long later.
Here’s a slimmed-down snippet of the relevant code:
class TransitionProcessor extends RichFlatMapFunction<Transition, Reaction> {
transient ValueState<IdSet> headSeenState;
public void open(final Configuration parameters) throws Exception {
headSeenState = FlinkUtil.getStateHandle(this, "head-seen",
IdSet.class);
getRuntimeContext()
.getMetricGroup()
.gauge("head-seen", new Gauge<Long>() {
public Long getValue() {
try {
return
headSeenState.value().count();
} catch (IOException e) {
e.printStackTrace();
return 0L;
}
}
});
}
…
}
FlinkUtil.getStateHandle instantiates a ValueStateDescriptor and acquires a
reference to that state via the RuntimeContext of the RichFunction passed as
‚this‘ in the above code.
Further along in the stack trace I see that headSeenState.value() results in a
call to org.apache.flink.contrib.streaming.state.RocksDBValueState.value() and
then to org.rocksdb.RocksDB.get(J[BIJ).
It looks like part of the metrics system asynchronously reads the value of the
gauge and needs RocksDB for that. Is it possible that this thread does not hold
the checkpointing lock you were talking about?
Best regards
Florian
> Am 22.03.2017 um 18:19 schrieb Stefan Richter <s.rich...@data-artisans.com>:
>
> Hi,
>
> for the first checkpoint, from the stacktrace I assume that the backend is
> not accessed as part of processing an element, but by another thread. Is that
> correct? RocksDB requires accessing threads to hold the task’s checkpointing
> lock, otherwise they might call methods on an instance that is already
> disposed. However, this should only happen when the task was already about to
> shutdown anyways. Is that a plausible explanation for your observed
> behaviour? I can also not rule out that segfaults can happen inside RocksDB
> or due to the JNI bridge.
>
> Best,
> Stefan
>
>> Am 22.03.2017 um 16:53 schrieb Florian König <florian.koe...@micardo.com>:
>>
>> Hi Stephen,
>>
>> you are right, the second stack trace is indeed from a run of Flink 1.1.4.
>> Sorry, my bad.
>>
>> That leaves us with the first trace of a segfault for which I can guarantee
>> that it brought down a 1.2.0 instance. Unfortunately I cannot reproduce the
>> problem. It has happened twice so far, but I can’t see any pattern. Is there
>> anything in the stack trace that could point us to a probable cause?
>>
>> Florian
>>
>>> Am 22.03.2017 um 16:00 schrieb Stephan Ewen <se...@apache.org>:
>>>
>>> Hi!
>>>
>>> It looks like you are running the RocksDB state backend 1.1 (is still an
>>> old version packaged into your JAR file?)
>>>
>>> This line indicates that:
>>> org.apache.flink.contrib.streaming.state.RocksDBStateBackend.performSemiAsyncSnapshot
>>> (the method does not exist in 1.2 any more)
>>>
>>> Can you try and run 1.2 and see if that still occurs? In general, I cannot
>>> vouch 100% for RocksDBs JNI API, but in our 1.2 tests so far it was stable.
>>>
>>> Stephan
>>>
>>>
>>>
>>> On Wed, Mar 22, 2017 at 3:13 PM, Florian König <florian.koe...@micardo.com>
>>> wrote:
>>> Hi,
>>>
>>> I have experienced two crashes of Flink 1.2 by SIGSEGV, caused by something
>>> in RocksDB. What is the preferred way to report them? All I got at the
>>> moment are two hs_err_pid12345.log files. They are over 4000 lines long
>>> each. Is there anything significant that I should extract to help you guys
>>> and/or put into a JIRA ticket?
>>>
>>> The first thing that came to my mind was the stack traces (see below).
>>> Anything else?
>>>
>>> Thanks
>>> Florian
>>>
>>> ----
>>>
>>> Stack: [0x00007fec04341000,0x00007fec04442000], sp=0x00007fec0443ff48,
>>> free space=1019k
>>> Java frames: (J=compiled Java code, j=interpreted, Vv=VM code)
>>> J 10252 org.rocksdb.RocksDB.get(J[BIJ)[B (0 bytes) @ 0x00007fec925887cc
>>> [0x00007fec92588780+0x4c]
>>> J 27241 C2
>>> org.apache.flink.contrib.streaming.state.RocksDBValueState.value()Ljava/lang/Object;
>>> (78 bytes) @ 0x00007fec94010ca4 [0x00007fec940109c0+0x2e4]
>>> j com.micardo.backend.TransitionProcessor$2.getValue()Ljava/lang/Long;+7
>>> j com.micardo.backend.TransitionProcessor$2.getValue()Ljava/lang/Object;+1
>>> J 38483 C2
>>> org.apache.flink.runtime.metrics.dump.MetricDumpSerialization.serializeGauge(Ljava/io/DataOutput;Lorg/apache/flink/runtime/metrics/dump/QueryScopeInfo;Ljava/lang/String;Lorg/apache/flink/metrics/Gauge;)V
>>> (114 bytes) @ 0x00007fec918eabf0 [0x00007fec918eabc0+0x30]
>>> J 38522 C2
>>> org.apache.flink.runtime.metrics.dump.MetricDumpSerialization$MetricDumpSerializer.serialize(Ljava/util/Map;Ljava/util/Map;Ljava/util/Map;Ljava/util/Map;)Lorg/apache/flink/runtime/metrics/dump/MetricDumpSerialization$MetricSerializationResult;
>>> (471 bytes) @ 0x00007fec94eb6260 [0x00007fec94eb57a0+0xac0]
>>> J 47531 C2
>>> org.apache.flink.runtime.metrics.dump.MetricQueryService.onReceive(Ljava/lang/Object;)V
>>> (453 bytes) @ 0x00007fec95ca57a0 [0x00007fec95ca4da0+0xa00]
>>> J 5815 C2
>>> akka.actor.UntypedActor.aroundReceive(Lscala/PartialFunction;Ljava/lang/Object;)V
>>> (7 bytes) @ 0x00007fec91e3ae6c [0x00007fec91e3adc0+0xac]
>>> J 5410 C2 akka.actor.ActorCell.invoke(Lakka/dispatch/Envelope;)V (104
>>> bytes) @ 0x00007fec91d5bc44 [0x00007fec91d5b9a0+0x2a4]
>>> J 6628 C2
>>> scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(Lscala/concurrent/forkjoin/ForkJoinTask;)V
>>> (60 bytes) @ 0x00007fec9212d050 [0x00007fec9212ccc0+0x390]
>>> J 40130 C2 scala.concurrent.forkjoin.ForkJoinWorkerThread.run()V (182
>>> bytes) @ 0x00007fec923f8170 [0x00007fec923f7fc0+0x1b0]
>>> v ~StubRoutines::call_stub
>>>
>>> --------------------------------------
>>>
>>> Stack: [0x00007f167a5b7000,0x00007f167a6b8000], sp=0x00007f167a6b5f40,
>>> free space=1019k
>>> Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native
>>> code)
>>> C [libstdc++.so.6+0xc026b] std::basic_string<char,
>>> std::char_traits<char>, std::allocator<char> >::basic_string(std::string
>>> const&)+0xb
>>> C [librocksdbjni8426686507832168508.so+0x2f14ca]
>>> rocksdb::BackupEngine::Open(rocksdb::Env*, rocksdb::BackupableDBOptions
>>> const&, rocksdb::BackupEngine**)+0x3a
>>> C [librocksdbjni8426686507832168508.so+0x180ad5]
>>> Java_org_rocksdb_BackupEngine_open+0x25
>>> J 50030 org.rocksdb.BackupEngine.open(JJ)J (0 bytes) @ 0x00007f16cb79aa36
>>> [0x00007f16cb79a980+0xb6]
>>> J 49809 C1
>>> org.apache.flink.contrib.streaming.state.RocksDBStateBackend.performSemiAsyncSnapshot(JJ)Ljava/util/HashMap;
>>> (416 bytes) @ 0x00007f16cd2733d4 [0x00007f16cd2719a0+0x1a34]
>>> J 51766 C2
>>> org.apache.flink.contrib.streaming.state.RocksDBStateBackend.snapshotPartitionedState(JJ)Ljava/util/HashMap;
>>> (40 bytes) @ 0x00007f16cb40a1fc [0x00007f16cb40a1a0+0x5c]
>>> J 50547 C2
>>> org.apache.flink.streaming.api.operators.AbstractUdfStreamOperator.snapshotOperatorState(JJ)Lorg/apache/flink/streaming/runtime/tasks/StreamTaskState;
>>> (206 bytes) @ 0x00007f16cb8be89c [0x00007f16cb8be7e0+0xbc]
>>> J 52232 C2
>>> org.apache.flink.streaming.runtime.tasks.StreamTask.performCheckpoint(JJ)Z
>>> (650 bytes) @ 0x00007f16cbfbbf60 [0x00007f16cbfbb540+0xa20]
>>> J 52419 C2
>>> org.apache.flink.streaming.runtime.io.BarrierBuffer.notifyCheckpoint(Lorg/apache/flink/runtime/io/network/api/CheckpointBarrier;)V
>>> (25 bytes) @ 0x00007f16cbdd2624 [0x00007f16cbdd25c0+0x64]
>>> J 41649 C2
>>> org.apache.flink.streaming.runtime.io.StreamInputProcessor.processInput(Lorg/apache/flink/streaming/api/operators/OneInputStreamOperator;Ljava/lang/Object;)Z
>>> (439 bytes) @ 0x00007f16cc8aed5c [0x00007f16cc8add40+0x101c]
>>> J 33374% C2
>>> org.apache.flink.streaming.runtime.tasks.OneInputStreamTask.run()V (42
>>> bytes) @ 0x00007f16cbdc21d0 [0x00007f16cbdc20c0+0x110]
>>> j org.apache.flink.streaming.runtime.tasks.StreamTask.invoke()V+301
>>> j org.apache.flink.runtime.taskmanager.Task.run()V+700
>>> j java.lang.Thread.run()V+11
>>> v ~StubRoutines::call_stub
>>> V [libjvm.so+0x68c616]
>>> V [libjvm.so+0x68cb21]
>>> V [libjvm.so+0x68cfc7]
>>> V [libjvm.so+0x723d80]
>>> V [libjvm.so+0xa69dcf]
>>> V [libjvm.so+0xa69efc]
>>> V [libjvm.so+0x91d9d8]
>>> C [libpthread.so.0+0x8064] start_thread+0xc4
>>>
>>> Java frames: (J=compiled Java code, j=interpreted, Vv=VM code)
>>> J 50030 org.rocksdb.BackupEngine.open(JJ)J (0 bytes) @ 0x00007f16cb79a9c4
>>> [0x00007f16cb79a980+0x44]
>>> J 49809 C1
>>> org.apache.flink.contrib.streaming.state.RocksDBStateBackend.performSemiAsyncSnapshot(JJ)Ljava/util/HashMap;
>>> (416 bytes) @ 0x00007f16cd2733d4 [0x00007f16cd2719a0+0x1a34]
>>> J 51766 C2
>>> org.apache.flink.contrib.streaming.state.RocksDBStateBackend.snapshotPartitionedState(JJ)Ljava/util/HashMap;
>>> (40 bytes) @ 0x00007f16cb40a1fc [0x00007f16cb40a1a0+0x5c]
>>> J 50547 C2
>>> org.apache.flink.streaming.api.operators.AbstractUdfStreamOperator.snapshotOperatorState(JJ)Lorg/apache/flink/streaming/runtime/tasks/StreamTaskState;
>>> (206 bytes) @ 0x00007f16cb8be89c [0x00007f16cb8be7e0+0xbc]
>>> J 52232 C2
>>> org.apache.flink.streaming.runtime.tasks.StreamTask.performCheckpoint(JJ)Z
>>> (650 bytes) @ 0x00007f16cbfbbf60 [0x00007f16cbfbb540+0xa20]
>>> J 52419 C2
>>> org.apache.flink.streaming.runtime.io.BarrierBuffer.notifyCheckpoint(Lorg/apache/flink/runtime/io/network/api/CheckpointBarrier;)V
>>> (25 bytes) @ 0x00007f16cbdd2624 [0x00007f16cbdd25c0+0x64]
>>> J 41649 C2
>>> org.apache.flink.streaming.runtime.io.StreamInputProcessor.processInput(Lorg/apache/flink/streaming/api/operators/OneInputStreamOperator;Ljava/lang/Object;)Z
>>> (439 bytes) @ 0x00007f16cc8aed5c [0x00007f16cc8add40+0x101c]
>>> J 33374% C2
>>> org.apache.flink.streaming.runtime.tasks.OneInputStreamTask.run()V (42
>>> bytes) @ 0x00007f16cbdc21d0 [0x00007f16cbdc20c0+0x110]
>>> j org.apache.flink.streaming.runtime.tasks.StreamTask.invoke()V+301
>>> j org.apache.flink.runtime.taskmanager.Task.run()V+700
>>> j java.lang.Thread.run()V+11
>>> v ~StubRoutines::call_stub
>>>
>>>
>>>
>>>
>>
>>
>
