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! >>>>>>> >>>>>> >>>>>> >>>>> >>>> >>> >> >
