<span style=" font-size:12pt;font-family:Arial">We can try to provide
some guidance on what you are seeing but generally to do true analysis
of performance issues customers should contact IBM lab based services (LBS).
We need some additional information to understand what is happening.</span><br><ul><li><span style=" font-size:12pt;font-family:Arial">On which node did you
collect the waiters and what command did you run to capture the data?</span><li><span style=" font-size:12pt;font-family:Arial">What is the network
connection between the remote cluster and the storage cluster?</span></ul><br><span style=" font-size:10pt;font-family:sans-serif">Regards, The Spectrum
Scale (GPFS) team<br><br>------------------------------------------------------------------------------------------------------------------<br>If you feel that your question can benefit other users of Spectrum
Scale (GPFS), then please post it to the public IBM developerWroks Forum
at </span><a href="https://www.ibm.com/developerworks/community/forums/html/forum?id=11111111-0000-0000-0000-000000000479"><span style=" font-size:10pt;font-family:sans-serif">https://www.ibm.com/developerworks/community/forums/html/forum?id=11111111-0000-0000-0000-000000000479</span></a><span style=" font-size:10pt;font-family:sans-serif">.
<br><br>If your query concerns a potential software error in Spectrum Scale (GPFS)
and you have an IBM software maintenance contract please contact 1-800-237-5511
in the United States or your local IBM Service Center in other countries.
<br><br>The forum is informally monitored as time permits and should not be used
for priority messages to the Spectrum Scale (GPFS) team.</span><br><br><br><br><span style=" font-size:9pt;color:#5f5f5f;font-family:sans-serif">From:
</span><span style=" font-size:9pt;font-family:sans-serif">"Caubet
Serrabou Marc (PSI)" <marc.caubet@psi.ch></span><br><span style=" font-size:9pt;color:#5f5f5f;font-family:sans-serif">To:
</span><span style=" font-size:9pt;font-family:sans-serif">gpfsug
main discussion list <gpfsug-discuss@spectrumscale.org></span><br><span style=" font-size:9pt;color:#5f5f5f;font-family:sans-serif">Date:
</span><span style=" font-size:9pt;font-family:sans-serif">04/18/2019
11:41 AM</span><br><span style=" font-size:9pt;color:#5f5f5f;font-family:sans-serif">Subject:
</span><span style=" font-size:9pt;font-family:sans-serif">[gpfsug-discuss]
Performance problems + (MultiThreadWorkInstanceCond), reason 'waiting for
helper threads'</span><br><span style=" font-size:9pt;color:#5f5f5f;font-family:sans-serif">Sent
by: </span><span style=" font-size:9pt;font-family:sans-serif">gpfsug-discuss-bounces@spectrumscale.org</span><br><hr noshade><br><br><br><span style=" font-size:10pt;font-family:Tahoma">Hi all,</span><br><br><span style=" font-size:10pt;font-family:Tahoma">I would like to have
some hints about the following problem:</span><br><br><span style=" font-size:10pt;font-family:Tahoma">Waiting 26.6431 sec
since 17:18:32, ignored, thread 38298 NSPDDiscoveryRunQueueThread: on ThCond
0x7FC98EB6A2B8 (MultiThreadWorkInstanceCond), reason 'waiting for helper
threads'</span><br><span style=" font-size:10pt;font-family:Tahoma">Waiting 2.7969 sec
since 17:18:55, monitored, thread 39736 NSDThread: for I/O completion<br>Waiting 2.8024 sec since 17:18:55, monitored, thread 39580 NSDThread: for
I/O completion<br>Waiting 3.0435 sec since 17:18:55, monitored, thread 39448 NSDThread: for
I/O completion<br></span><br><span style=" font-size:10pt;font-family:Tahoma">I am testing a new
GPFS cluster (GPFS cluster client with computing nodes remotely mounting
the Storage GPFS Cluster) and I am running 65 gpfsperf commands (1 command
per client in parallell) as follows:</span><br><br><span style=" font-size:10pt;font-family:Tahoma">/usr/lpp/mmfs/samples/perf/gpfsperf
create seq /gpfs/home/caubet_m/gpfsperf/$(hostname).txt -fsync -n 24g -r
16m -th 8 </span><br><br><span style=" font-size:10pt;font-family:Tahoma">I am unable to reach
more than 6.5GBps (Lenovo DSS G240 GPFS 5.0.2-1, on a testing a 'home'
filesystem with 1MB blocksize and subblocks of 8KB). After several seconds
I see many waiters for I/O completion (up to 5 seconds)</span><br><span style=" font-size:10pt;font-family:Tahoma">and also the 'waiting
for helper threads' message shown above. Can somebody explain me the meaning
for this message? How could I improve that?</span><br><br><span style=" font-size:10pt;font-family:Tahoma">Current config in
the storage cluster is:</span><br><br><span style=" font-size:10pt;font-family:Tahoma">[root@merlindssio02
~]# mmlsconfig <br>Configuration data for cluster merlin.psi.ch:<br>---------------------------------------------<br>clusterName merlin.psi.ch<br>clusterId 1511090979434548295<br>autoload no<br>dmapiFileHandleSize 32<br>minReleaseLevel 5.0.2.0<br>ccrEnabled yes<br>nsdRAIDFirmwareDirectory /opt/lenovo/dss/firmware<br>cipherList AUTHONLY<br>maxblocksize 16m<br>[merlindssmgt01]<br>ignorePrefetchLUNCount yes<br>[common]<br>pagepool 4096M<br>[merlindssio01,merlindssio02]<br>pagepool 270089M<br>[merlindssmgt01,dssg]<br>pagepool 57684M<br>maxBufferDescs 2m<br>numaMemoryInterleave yes<br>[common]<br>prefetchPct 50<br>[merlindssmgt01,dssg]<br>prefetchPct 20<br>nsdRAIDTracks 128k<br>nsdMaxWorkerThreads 3k<br>nsdMinWorkerThreads 3k<br>nsdRAIDSmallThreadRatio 2<br>nsdRAIDThreadsPerQueue 16<br>nsdClientCksumTypeLocal ck64<br>nsdClientCksumTypeRemote ck64<br>nsdRAIDFlusherFWLogHighWatermarkMB 1000<br>nsdRAIDBlockDeviceMaxSectorsKB 0<br>nsdRAIDBlockDeviceNrRequests 0<br>nsdRAIDBlockDeviceQueueDepth 0<br>nsdRAIDBlockDeviceScheduler off<br>nsdRAIDMaxPdiskQueueDepth 128<br>nsdMultiQueue 512<br>verbsRdma enable<br>verbsPorts mlx5_0/1 mlx5_1/1<br>verbsRdmaSend yes<br>scatterBufferSize 256K<br>maxFilesToCache 128k<br>maxMBpS 40000<br>workerThreads 1024<br>nspdQueues 64<br>[common]<br>subnets 192.168.196.0/merlin-hpc.psi.ch;merlin.psi.ch<br>adminMode central<br><br>File systems in cluster merlin.psi.ch:<br>--------------------------------------<br>/dev/home<br>/dev/t16M128K<br>/dev/t16M16K<br>/dev/t1M8K<br>/dev/t4M16K<br>/dev/t4M32K<br>/dev/test</span><br><br><span style=" font-size:10pt;font-family:Tahoma">And for the computing
cluster:</span><br><br><span style=" font-size:10pt;font-family:Tahoma">[root@merlin-c-001
~]# mmlsconfig <br>Configuration data for cluster merlin-hpc.psi.ch:<br>-------------------------------------------------<br>clusterName merlin-hpc.psi.ch<br>clusterId 14097036579263601931<br>autoload yes<br>dmapiFileHandleSize 32<br>minReleaseLevel 5.0.2.0<br>ccrEnabled yes<br>cipherList AUTHONLY<br>maxblocksize 16M<br>numaMemoryInterleave yes<br>maxFilesToCache 128k<br>maxMBpS 20000<br>workerThreads 1024<br>verbsRdma enable<br>verbsPorts mlx5_0/1<br>verbsRdmaSend yes<br>scatterBufferSize 256K<br>ignorePrefetchLUNCount yes<br>nsdClientCksumTypeLocal ck64<br>nsdClientCksumTypeRemote ck64<br>pagepool 32G<br>subnets 192.168.196.0/merlin-hpc.psi.ch;merlin.psi.ch<br>adminMode central<br><br>File systems in cluster merlin-hpc.psi.ch:<br>------------------------------------------<br>(none)</span><br><br><span style=" font-size:10pt;font-family:Tahoma">Thanks a lot and best
regards,</span><br><span style=" font-size:10pt;font-family:Tahoma">Marc
</span><br><span style=" font-size:10pt;font-family:Tahoma">_________________________________________<br>Paul Scherrer Institut <br>High Performance Computing<br>Marc Caubet Serrabou<br>Building/Room: WHGA/019A</span><br><span style=" font-size:10pt;font-family:Tahoma">Forschungsstrasse,
111</span><br><span style=" font-size:10pt;font-family:Tahoma">5232 Villigen PSI<br>Switzerland<br><br>Telephone: +41 56 310 46 67<br>E-Mail: marc.caubet@psi.ch</span><tt><span style=" font-size:10pt">_______________________________________________<br>gpfsug-discuss mailing list<br>gpfsug-discuss at spectrumscale.org<br></span></tt><a href="http://gpfsug.org/mailman/listinfo/gpfsug-discuss"><tt><span style=" font-size:10pt">http://gpfsug.org/mailman/listinfo/gpfsug-discuss</span></tt></a><tt><span style=" font-size:10pt"><br></span></tt><br><br><BR>