If you are doing only writes and no reads, then 'cold_reads_to_omit' is probably preventing your cluster from crossing a threshold where it decides it needs to engage in compaction. Setting it to 0.0 should fix this, but remember that you tuned it as you should be able to revert it to default thresholds once you start engaging in reads.
On Mon, Jan 26, 2015 at 3:20 AM, 曹志富 <cao.zh...@gmail.com> wrote: > I read the CQL table properties again.This property could contorl the > compaction . Right now My C* cluster only write without any read. > > -------------------------------------- > 曹志富 > 手机：18611121927 > 邮箱：caozf.zh...@gmail.com > 微博：http://weibo.com/boliza/ > > 2015-01-26 17:41 GMT+08:00 Roland Etzenhammer <r.etzenham...@t-online.de>: > >> Hi, >> >> are you running 2.1.2 evenutally? I had this problem recently and there >> were two topics here about this. Problem was, that my test cluster had >> almost no reads and did not compact sstables. >> >> Reason for me was that those minor compactions did not get triggered >> since there were almost no reads on that tables. Setting >> 'cold_reads_to_omit' to 0 did the job for me: >> >> ALTER TABLE <tablename> WITH compaction = {'class': >> 'SizeTieredCompactionStrategy', 'min_threshold': '4', 'max_threshold': >> '32', 'cold_reads_to_omit': 0.0}; >> >> Credits to Tyler and Eric for the pointers. >> >> >> Maybe that could help. >> >> Cheers, >> Roland >> >> Am 26.01.2015 um 09:56 schrieb 曹志富: >> >> No,to confirm this I have run the command all my nodes:bin/nodetool >> enableautocompaction >> >> -------------------------------------- >> 曹志富 >> 手机：18611121927 >> 邮箱：caozf.zh...@gmail.com >> 微博：http://weibo.com/boliza/ >> >> 2015-01-26 16:49 GMT+08:00 Jason Wee <peich...@gmail.com>: >> >>> Did you disable auto compaction through nodetool? >>> >>> disableautocompaction Disable autocompaction for the given >>> keyspace and column family >>> >>> Jason >>> >>> On Mon, Jan 26, 2015 at 11:34 AM, 曹志富 <cao.zh...@gmail.com> wrote: >>> >>>> Hi everybody: >>>> >>>> I have 18 nodes using cassandra2.1.2.Every node has 4 core, 32 GB RAM, >>>> 2T hard disk,OS is CentOS release 6.2 (Final). >>>> >>>> I have follow the <Recommended production settings> to config my >>>> system.such as disable SWAP,unlimited mem lock... >>>> >>>> My heap size is: >>>> >>>> MAX_HEAP_SIZE="8G" >>>> MIN_HEAP_SIZE="8G" >>>> HEAP_NEWSIZE="2G" >>>> >>>> I use STCS,other config using default,using Datastax Java Driver >>>> 2.1.2. BatchStatment 100key commit per time. >>>> >>>> When I run my cluster and insert data from kafka (10000 keys/s) after >>>> 2 days,every node can't compact some there too many sstables. >>>> >>>> I try to use major compact to compact the sstables , it cost a long >>>> long time .Also the new sstables can't compat automatic. >>>> >>>> >>>> I trace the log , the CMS GC too often,almost 30 minute onetime. >>>> >>>> Could someone help me to solve this problem. >>>> >>>> >>>> -------------------------------------- >>>> 曹志富 >>>> 手 机：18611121927 >>>> 邮箱：caozf.zh...@gmail.com >>>> 微博：http://weibo.com/boliza/ >>>> >>> >>> >> >> >
