So it seems I found the problem. The node opening a stream is waiting for the other node to respond but that node never responds due to a broken pipe which makes Cassandra wait forever.
It's basically this issue: https://issues.apache.org/jira/browse/CASSANDRA-8472 And this is the workaround/fix: https://issues.apache.org/jira/browse/CASSANDRA-8611 So: - update cassandra to >=2.0.11 - add option streaming_socket_timeout_in_ms = 10000 - do rolling restart of cassandra What's weird is that the IOException: Broken pipe is never shown in my logs (not on any node). And my logging is set to INFO in log4j config. I have this config in log4j-server.properties: # output messages into a rolling log file as well as stdout log4j.rootLogger=INFO,stdout,R # stdout log4j.appender.stdout=org.apache.log4j.ConsoleAppender log4j.appender.stdout.layout=org.apache.log4j.PatternLayout log4j.appender.stdout.layout.ConversionPattern=%5p %d{HH:mm:ss,SSS} %m%n # rolling log file log4j.appender.R=org.apache.log4j.RollingFileAppender log4j.appender.R.maxFileSize=20MB log4j.appender.R.maxBackupIndex=50 log4j.appender.R.layout=org.apache.log4j.PatternLayout log4j.appender.R.layout.ConversionPattern=%5p [%t] %d{ISO8601} %F (line %L) %m%n # Edit the next line to point to your logs directory log4j.appender.R.File=/var/log/cassandra/system.log # Application logging options #log4j.logger.org.apache.cassandra=DEBUG #log4j.logger.org.apache.cassandra.db=DEBUG #log4j.logger.org.apache.cassandra.service.StorageProxy=DEBUG # Adding this to avoid thrift logging disconnect errors. log4j.logger.org.apache.thrift.server.TNonblockingServer=ERROR Too bad nobody else could point to those. Hope it helps someone else from wasting a lot of time. 2015-11-11 15:42 GMT+01:00 Sebastian Estevez <sebastian.este...@datastax.com >: > Use 'nodetool compactionhistory' > > all the best, > > Sebastián > On Nov 11, 2015 3:23 AM, "PenguinWhispererThe ." < > th3penguinwhispe...@gmail.com> wrote: > >> Does compactionstats shows only stats for completed compactions (100%)? >> It might be that the compaction is running constantly, over and over again. >> In that case I need to know what I might be able to do to stop this >> constant compaction so I can start a nodetool repair. >> >> Note that there is a lot of traffic on this columnfamily so I'm not sure >> if temporary disabling compaction is an option. The repair will probably >> take long as well. >> >> Sebastian and Rob: do you might have any more ideas about the things I >> put in this thread? Any help is appreciated! >> >> 2015-11-10 20:03 GMT+01:00 PenguinWhispererThe . < >> th3penguinwhispe...@gmail.com>: >> >>> Hi Sebastian, >>> >>> Thanks for your response. >>> >>> No swap is used. No offense, I just don't see a reason why having swap >>> would be the issue here. I put swapiness on 1. I also have jna installed. >>> That should prevent java being swapped out as wel AFAIK. >>> >>> >>> 2015-11-10 19:50 GMT+01:00 Sebastian Estevez < >>> sebastian.este...@datastax.com>: >>> >>>> Turn off Swap. >>>> >>>> >>>> http://docs.datastax.com/en/cassandra/2.1/cassandra/install/installRecommendSettings.html?scroll=reference_ds_sxl_gf3_2k__disable-swap >>>> >>>> >>>> All the best, >>>> >>>> >>>> [image: datastax_logo.png] <http://www.datastax.com/> >>>> >>>> Sebastián Estévez >>>> >>>> Solutions Architect | 954 905 8615 | sebastian.este...@datastax.com >>>> >>>> [image: linkedin.png] <https://www.linkedin.com/company/datastax> [image: >>>> facebook.png] <https://www.facebook.com/datastax> [image: twitter.png] >>>> <https://twitter.com/datastax> [image: g+.png] >>>> <https://plus.google.com/+Datastax/about> >>>> <http://feeds.feedburner.com/datastax> >>>> <http://goog_410786983> >>>> >>>> >>>> <http://www.datastax.com/gartner-magic-quadrant-odbms> >>>> >>>> DataStax is the fastest, most scalable distributed database >>>> technology, delivering Apache Cassandra to the world’s most innovative >>>> enterprises. Datastax is built to be agile, always-on, and predictably >>>> scalable to any size. With more than 500 customers in 45 countries, >>>> DataStax >>>> is the database technology and transactional backbone of choice for the >>>> worlds most innovative companies such as Netflix, Adobe, Intuit, and eBay. >>>> >>>> On Tue, Nov 10, 2015 at 1:48 PM, PenguinWhispererThe . < >>>> th3penguinwhispe...@gmail.com> wrote: >>>> >>>>> I also have the following memory usage: >>>>> [root@US-BILLINGDSX4 cassandra]# free -m >>>>> total used free shared buffers >>>>> cached >>>>> Mem: 12024 9455 2569 0 110 >>>>> 2163 >>>>> -/+ buffers/cache: 7180 4844 >>>>> Swap: 2047 0 2047 >>>>> >>>>> Still a lot free and a lot of free buffers/cache. >>>>> >>>>> 2015-11-10 19:45 GMT+01:00 PenguinWhispererThe . < >>>>> th3penguinwhispe...@gmail.com>: >>>>> >>>>>> Still stuck with this. However I enabled GC logging. This shows the >>>>>> following: >>>>>> >>>>>> [root@myhost cassandra]# tail -f gc-1447180680.log >>>>>> 2015-11-10T18:41:45.516+0000: 225.428: [GC >>>>>> 2721842K->2066508K(6209536K), 0.0199040 secs] >>>>>> 2015-11-10T18:41:45.977+0000: 225.889: [GC >>>>>> 2721868K->2066511K(6209536K), 0.0221910 secs] >>>>>> 2015-11-10T18:41:46.437+0000: 226.349: [GC >>>>>> 2721871K->2066524K(6209536K), 0.0222140 secs] >>>>>> 2015-11-10T18:41:46.897+0000: 226.809: [GC >>>>>> 2721884K->2066539K(6209536K), 0.0224140 secs] >>>>>> 2015-11-10T18:41:47.359+0000: 227.271: [GC >>>>>> 2721899K->2066538K(6209536K), 0.0302520 secs] >>>>>> 2015-11-10T18:41:47.821+0000: 227.733: [GC >>>>>> 2721898K->2066557K(6209536K), 0.0280530 secs] >>>>>> 2015-11-10T18:41:48.293+0000: 228.205: [GC >>>>>> 2721917K->2066571K(6209536K), 0.0218000 secs] >>>>>> 2015-11-10T18:41:48.790+0000: 228.702: [GC >>>>>> 2721931K->2066780K(6209536K), 0.0292470 secs] >>>>>> 2015-11-10T18:41:49.290+0000: 229.202: [GC >>>>>> 2722140K->2066843K(6209536K), 0.0288740 secs] >>>>>> 2015-11-10T18:41:49.756+0000: 229.668: [GC >>>>>> 2722203K->2066818K(6209536K), 0.0283380 secs] >>>>>> 2015-11-10T18:41:50.249+0000: 230.161: [GC >>>>>> 2722178K->2067158K(6209536K), 0.0218690 secs] >>>>>> 2015-11-10T18:41:50.713+0000: 230.625: [GC >>>>>> 2722518K->2067236K(6209536K), 0.0278810 secs] >>>>>> >>>>>> This is a VM with 12GB of RAM. Highered the HEAP_SIZE to 6GB and >>>>>> HEAP_NEWSIZE to 800MB. >>>>>> >>>>>> Still the same result. >>>>>> >>>>>> This looks very similar to following issue: >>>>>> >>>>>> http://mail-archives.apache.org/mod_mbox/cassandra-user/201411.mbox/%3CCAJ=3xgRLsvpnZe0uXEYjG94rKhfXeU+jBR=q3a-_c3rsdd5...@mail.gmail.com%3E >>>>>> >>>>>> Is the only possibility to upgrade memory? I mean, I can't believe >>>>>> it's just loading all it's data in memory. That would require to keep >>>>>> scaling up the node to keep it work? >>>>>> >>>>>> >>>>>> 2015-11-10 9:36 GMT+01:00 PenguinWhispererThe . < >>>>>> th3penguinwhispe...@gmail.com>: >>>>>> >>>>>>> Correction... >>>>>>> I was grepping on Segmentation on the strace and it happens a lot. >>>>>>> >>>>>>> Do I need to run a scrub? >>>>>>> >>>>>>> 2015-11-10 9:30 GMT+01:00 PenguinWhispererThe . < >>>>>>> th3penguinwhispe...@gmail.com>: >>>>>>> >>>>>>>> Hi Rob, >>>>>>>> >>>>>>>> Thanks for your reply. >>>>>>>> >>>>>>>> 2015-11-09 23:17 GMT+01:00 Robert Coli <rc...@eventbrite.com>: >>>>>>>> >>>>>>>>> On Mon, Nov 9, 2015 at 1:29 PM, PenguinWhispererThe . < >>>>>>>>> th3penguinwhispe...@gmail.com> wrote: >>>>>>>>>> >>>>>>>>>> In Opscenter I see one of the nodes is orange. It seems like it's >>>>>>>>>> working on compaction. I used nodetool compactionstats and whenever >>>>>>>>>> I did >>>>>>>>>> this the Completed nad percentage stays the same (even with hours in >>>>>>>>>> between). >>>>>>>>>> >>>>>>>>> Are you the same person from IRC, or a second report today of >>>>>>>>> compaction hanging in this way? >>>>>>>>> >>>>>>>> Same person ;) Just didn't had things to work with from the chat >>>>>>>> there. I want to understand the issue more, see what I can tune or >>>>>>>> fix. I >>>>>>>> want to do nodetool repair before upgrading to 2.1.11 but the >>>>>>>> compaction is >>>>>>>> blocking it. >>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>> What version of Cassandra? >>>>>>>>> >>>>>>>> 2.0.9 >>>>>>>> >>>>>>>>> I currently don't see cpu load from cassandra on that node. So it >>>>>>>>>> seems stuck (somewhere mid 60%). Also some other nodes have >>>>>>>>>> compaction on >>>>>>>>>> the same columnfamily. I don't see any progress. >>>>>>>>>> >>>>>>>>>> WARN [RMI TCP Connection(554)-192.168.0.68] 2015-11-09 17:18:13,677 >>>>>>>>>> ColumnFamilyStore.java (line 2101) Unable to cancel in-progress >>>>>>>>>> compactions for usage_record_ptd. Probably there is an unusually >>>>>>>>>> large row in progress somewhere. It is also possible that buggy >>>>>>>>>> code left some sstables compacting after it was done with them >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> - How can I assure that nothing is happening? >>>>>>>>>> >>>>>>>>>> Find the thread that is doing compaction and strace it. Generally >>>>>>>>> it is one of the threads with a lower thread priority. >>>>>>>>> >>>>>>>> >>>>>>>> I have 141 threads. Not sure if that's normal. >>>>>>>> >>>>>>>> This seems to be the one: >>>>>>>> 61404 cassandr 24 4 8948m 4.3g 820m R 90.2 36.8 292:54.47 java >>>>>>>> >>>>>>>> In the strace I see basically this part repeating (with once in a >>>>>>>> while the "resource temporarily unavailable"): >>>>>>>> futex(0x7f5c64145e54, FUTEX_WAKE_OP_PRIVATE, 1, 1, 0x7f5c64145e50, >>>>>>>> {FUTEX_OP_SET, 0, FUTEX_OP_CMP_GT, 1}) = 1 >>>>>>>> futex(0x7f5c64145e28, FUTEX_WAKE_PRIVATE, 1) = 1 >>>>>>>> getpriority(PRIO_PROCESS, 61404) = 16 >>>>>>>> futex(0x7f5c64145e54, FUTEX_WAKE_OP_PRIVATE, 1, 1, 0x7f5c64145e50, >>>>>>>> {FUTEX_OP_SET, 0, FUTEX_OP_CMP_GT, 1}) = 1 >>>>>>>> futex(0x7f5c64145e28, FUTEX_WAKE_PRIVATE, 1) = 0 >>>>>>>> futex(0x1233854, FUTEX_WAIT_PRIVATE, 494045, NULL) = -1 EAGAIN >>>>>>>> (Resource temporarily unavailable) >>>>>>>> futex(0x1233828, FUTEX_WAKE_PRIVATE, 1) = 0 >>>>>>>> futex(0x7f5c64145e54, FUTEX_WAKE_OP_PRIVATE, 1, 1, 0x7f5c64145e50, >>>>>>>> {FUTEX_OP_SET, 0, FUTEX_OP_CMP_GT, 1}) = 1 >>>>>>>> futex(0x7f5c64145e28, FUTEX_WAKE_PRIVATE, 1) = 1 >>>>>>>> futex(0x1233854, FUTEX_WAIT_PRIVATE, 494047, NULL) = 0 >>>>>>>> futex(0x1233828, FUTEX_WAKE_PRIVATE, 1) = 0 >>>>>>>> futex(0x7f5c64145e54, FUTEX_WAKE_OP_PRIVATE, 1, 1, 0x7f5c64145e50, >>>>>>>> {FUTEX_OP_SET, 0, FUTEX_OP_CMP_GT, 1}) = 1 >>>>>>>> futex(0x7f5c64145e28, FUTEX_WAKE_PRIVATE, 1) = 1 >>>>>>>> getpriority(PRIO_PROCESS, 61404) = 16 >>>>>>>> futex(0x7f5c64145e54, FUTEX_WAKE_OP_PRIVATE, 1, 1, 0x7f5c64145e50, >>>>>>>> {FUTEX_OP_SET, 0, FUTEX_OP_CMP_GT, 1}) = 1 >>>>>>>> futex(0x7f5c64145e28, FUTEX_WAKE_PRIVATE, 1) = 1 >>>>>>>> futex(0x1233854, FUTEX_WAIT_PRIVATE, 494049, NULL) = 0 >>>>>>>> futex(0x1233828, FUTEX_WAKE_PRIVATE, 1) = 0 >>>>>>>> getpriority(PRIO_PROCESS, 61404) = 16 >>>>>>>> >>>>>>>> But wait! >>>>>>>> I also see this: >>>>>>>> futex(0x7f5c64145e54, FUTEX_WAKE_OP_PRIVATE, 1, 1, 0x7f5c64145e50, >>>>>>>> {FUTEX_OP_SET, 0, FUTEX_OP_CMP_GT, 1}) = 1 >>>>>>>> futex(0x1233854, FUTEX_WAIT_PRIVATE, 494055, NULL) = 0 >>>>>>>> futex(0x1233828, FUTEX_WAKE_PRIVATE, 1) = 0 >>>>>>>> --- SIGSEGV (Segmentation fault) @ 0 (0) --- >>>>>>>> >>>>>>>> This doesn't seem to happen that often though. >>>>>>>> >>>>>>>>> >>>>>>>>> Compaction often appears hung when decompressing a very large row, >>>>>>>>> but usually not for "hours". >>>>>>>>> >>>>>>>>>> >>>>>>>>>> - Is it recommended to disable compaction from a certain data >>>>>>>>>> size? (I believe 25GB on each node). >>>>>>>>>> >>>>>>>>>> It is almost never recommended to disable compaction. >>>>>>>>> >>>>>>>>>> >>>>>>>>>> - Can I stop this compaction? nodetool stop compaction >>>>>>>>>> doesn't seem to work. >>>>>>>>>> >>>>>>>>>> Killing the JVM ("the dungeon collapses!") would certainly stop >>>>>>>>> it, but it'd likely just start again when you restart the node. >>>>>>>>> >>>>>>>>>> >>>>>>>>>> - Is stopping the compaction dangerous? >>>>>>>>>> >>>>>>>>>> Not if you're in a version that properly cleans up partial >>>>>>>>> compactions, which is most of them. >>>>>>>>> >>>>>>>>>> >>>>>>>>>> - Is killing the cassandra process dangerous while >>>>>>>>>> compacting(I did nodetool drain on one node)? >>>>>>>>>> >>>>>>>>>> No. But probably nodetool drain couldn't actually stop the >>>>>>>>> in-progress compaction either, FWIW. >>>>>>>>> >>>>>>>>>> This is output of nodetool compactionstats grepped for the >>>>>>>>>> keyspace that seems stuck. >>>>>>>>>> >>>>>>>>>> Do you have gigantic rows in that keyspace? What does cfstats say >>>>>>>>> about the largest row compaction has seen/do you have log messages >>>>>>>>> about >>>>>>>>> compacting large rows? >>>>>>>>> >>>>>>>> >>>>>>>> I don't know about the gigantic rows. How can I check? >>>>>>>> >>>>>>>> I've checked the logs and found this: >>>>>>>> INFO [CompactionExecutor:67] 2015-11-10 02:34:19,077 >>>>>>>> CompactionController.java (line 192) Compacting large row >>>>>>>> billing/usage_record_ptd:177727:2015-10-14 00\:00Z (243992466 bytes) >>>>>>>> incrementally >>>>>>>> So this is from 6 hours ago. >>>>>>>> >>>>>>>> I also see a lot of messages like this: >>>>>>>> INFO [OptionalTasks:1] 2015-11-10 06:36:06,395 MeteredFlusher.java >>>>>>>> (line 58) flushing high-traffic column family >>>>>>>> CFS(Keyspace='mykeyspace', >>>>>>>> ColumnFamily='mycolumnfamily') (estimated 100317609 bytes) >>>>>>>> And (although it's unrelated this might impact compaction >>>>>>>> performance?): >>>>>>>> WARN [Native-Transport-Requests:10514] 2015-11-10 06:33:34,172 >>>>>>>> BatchStatement.java (line 223) Batch of prepared statements for >>>>>>>> [billing.usage_record_ptd] is of size 13834, exceeding specified >>>>>>>> threshold >>>>>>>> of 5120 by 8714. >>>>>>>> >>>>>>>> It's like the compaction is only doing one sstable at a time and is >>>>>>>> doing nothing a long time in between. >>>>>>>> >>>>>>>> cfstats for this keyspace and columnfamily gives the following: >>>>>>>> Table: mycolumnfamily >>>>>>>> SSTable count: 26 >>>>>>>> Space used (live), bytes: 319858991 >>>>>>>> Space used (total), bytes: 319860267 >>>>>>>> SSTable Compression Ratio: 0.24265700071674673 >>>>>>>> Number of keys (estimate): 6656 >>>>>>>> Memtable cell count: 22710 >>>>>>>> Memtable data size, bytes: 3310654 >>>>>>>> Memtable switch count: 31 >>>>>>>> Local read count: 0 >>>>>>>> Local read latency: 0.000 ms >>>>>>>> Local write count: 997667 >>>>>>>> Local write latency: 0.000 ms >>>>>>>> Pending tasks: 0 >>>>>>>> Bloom filter false positives: 0 >>>>>>>> Bloom filter false ratio: 0.00000 >>>>>>>> Bloom filter space used, bytes: 12760 >>>>>>>> Compacted partition minimum bytes: 1332 >>>>>>>> Compacted partition maximum bytes: 43388628 >>>>>>>> Compacted partition mean bytes: 234682 >>>>>>>> Average live cells per slice (last five minutes): >>>>>>>> 0.0 >>>>>>>> Average tombstones per slice (last five minutes): >>>>>>>> 0.0 >>>>>>>> >>>>>>>> >>>>>>>>> I also see frequently lines like this in system.log: >>>>>>>>>> >>>>>>>>>> WARN [Native-Transport-Requests:11935] 2015-11-09 20:10:41,886 >>>>>>>>>> BatchStatement.java (line 223) Batch of prepared statements for >>>>>>>>>> [billing.usage_record_by_billing_period, billing.metric] is of size >>>>>>>>>> 53086, exceeding specified threshold of 5120 by 47966. >>>>>>>>>> >>>>>>>>>> >>>>>>>>> Unrelated. >>>>>>>>> >>>>>>>>> =Rob >>>>>>>>> >>>>>>>>> >>>>>>>> >>>>>>>> Can I upgrade to 2.1.11 without doing a nodetool repair/compaction >>>>>>>> being stuck? >>>>>>>> Another thing to mention is that nodetool repair didn't run yet. It >>>>>>>> got installed but nobody bothered to schedule the repair. >>>>>>>> >>>>>>>> Thanks for looking into this! >>>>>>>> >>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>> >>
