Hi,
Truncatehints on nodes is running for more than 7 hours now. Nothing mentioned for same in sysemt logs even. And compaction stats reports increase in hints total bytes. pending tasks: 1 compaction type keyspace table completed total unit progress Compaction system hints 12152557998 869257869352 bytes 1.40% Active compaction remaining time : 0h27m14s Can anything else be checked here? Will manually deleting system.hint files and restart node fix this. Regards, Varun Saluja On 16 May 2017 at 23:29, varun saluja <saluj...@gmail.com> wrote: > Hi Jeff, > > I ran nodetool truncatehints on all nodes. Its running for more than 30 > mins now. Status for compactstats reports same. > > pending tasks: 1 > compaction type keyspace table completed total unit > progress > Compaction system hints 11189118129 851658989612 bytes > 1.31% > Active compaction remaining time : 0h26m43s > > Will truncatehints takes time for completion? Could not see anything > related truncatehints in system logs. > > Please let me know if anything else can be checked here. > > Regards, > Varun Saluja > > > > On 16 May 2017 at 20:58, varun saluja <saluj...@gmail.com> wrote: > >> Thanks a lot Jeff. >> >> You have explaned very well here. We have consitency as local quorum. >> Will follow truncate hints and repair therafter. >> >> I hope this brings cluster in stable state >> >> Thanks again. >> >> Regards, >> Varun Saluja >> >> Sent from my iPhone >> >> > On 16-May-2017, at 8:42 PM, Jeff Jirsa <jji...@apache.org> wrote: >> > >> > >> > In Cassandra versions up to 3.0, hints are stored within a table, where >> the partition key is the host ID of the server for which the hints are >> stored. >> > >> > In such a data model, accumulating 800GB of hints is almost certain to >> cause very wide rows, which will in turn cause GC pressure when you attempt >> to read the hints for delivery. This will cause GC pauses, which will cause >> hints to fail to be delivered, which will cause more hints to be stored. >> This is bad. >> > >> > In 3.0, hints were rewritten to work around this design flaw. In 2.1, >> your most likely corrective course is to use 'nodetool truncatehints' on >> all servers, followed by 'nodetool repair' to deliver the data you lost by >> truncating the hints. >> > >> > NOTE: this is ONLY safe if you wrote with a consistency level stronger >> than CL:ANY. If you wrote this data with CL:ANY, you may lose data if you >> truncate hints. >> > >> > - Jeff >> > >> >> On 2017-05-16 06:50 (-0700), varun saluja <saluj...@gmail.com> wrote: >> >> Thanks for update. >> >> I could see lot of io waits. This causing Gc and mutation drops . >> >> But as i mentioned we do not have high load for now. Hint replays are >> creating such high disk I/O. >> >> compactionstats show very high hint bytes like 780gb around. Is this >> normal? >> >> >> >> Just mentioning we are using flash disks. >> >> >> >> In such case, if i run truncatehints , will it remove or decrease size >> of hints bytes in compaction stats. I can trigger repair therafter. >> >> Please let me know if any recommendation on same. >> >> >> >> Also , table which we dumped from kafka which created this much hints >> and compaction pendings is also dropped today. Because we have to redump >> table again once cluster is stable. >> >> >> >> Regards, >> >> Varun >> >> >> >> Sent from my iPhone >> >> >> >>> On 16-May-2017, at 6:59 PM, Nitan Kainth <ni...@bamlabs.com> wrote: >> >>> >> >>> Yes but it means data has to be replicated using repair. >> >>> >> >>> Hints are out come of unhealthy nodes, focus on finding why you have >> mutation drops, is it node, io or network etc. ideally you shouldn't see >> increasing hints all the time. >> >>> >> >>> Sent from my iPhone >> >>> >> >>>> On May 16, 2017, at 7:58 AM, varun saluja <saluj...@gmail.com> >> wrote: >> >>>> >> >>>> Hi Nitan, >> >>>> >> >>>> Thanks for response. >> >>>> >> >>>> Yes, I could see mutation drops and increase count in system.hints. >> Is there any way , i can proceed to truncate hints like using nodetool >> truncatehints. >> >>>> >> >>>> >> >>>> Regards, >> >>>> Varun Saluja >> >>>> >> >>>>> On 16 May 2017 at 17:52, Nitan Kainth <ni...@bamlabs.com> wrote: >> >>>>> Do you see mutation drops? >> >>>>> Select count from system.hints; is it increasing? >> >>>>> >> >>>>> Sent from my iPhone >> >>>>> >> >>>>>> On May 16, 2017, at 5:52 AM, varun saluja <saluj...@gmail.com> >> wrote: >> >>>>>> >> >>>>>> Hi Experts, >> >>>>>> >> >>>>>> We are facing issue on production cluster. Compaction on >> system.hint table is running from last 2 days. >> >>>>>> >> >>>>>> >> >>>>>> pending tasks: 1 >> >>>>>> compaction type keyspace table completed total >> unit progress >> >>>>>> Compaction system hints 20623021829 >> 877874092407 bytes 2.35% >> >>>>>> Active compaction remaining time : 0h27m15s >> >>>>>> >> >>>>>> >> >>>>>> Active compaction remaining time shows in minutes. But, this is >> job is running like indefinitely. >> >>>>>> >> >>>>>> We have 3 node cluster V 2.1.7. And we ran write intensive job >> last week on particular table. >> >>>>>> Compaction on this table finished but hint table size is growing >> continuously. >> >>>>>> >> >>>>>> Can someone Please help me. >> >>>>>> >> >>>>>> >> >>>>>> Thanks & Regards, >> >>>>>> Varun Saluja >> >>>>>> >> >>>> >> >> >> > >> > --------------------------------------------------------------------- >> > To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org >> > For additional commands, e-mail: user-h...@cassandra.apache.org >> > >> > >