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From Vitalii Tymchyshyn <tiv...@gmail.com>
Subject Re: Cassandra dying when gets many deletes
Date Tue, 24 Apr 2012 09:00:12 GMT
Hello.

For me " there are no dirty column families" in your message tells it's 
possibly the same problem.
The issue is that column families that gets full row deletes only do not 
get ANY SINGLE dirty byte accounted and so can't be picked by flusher. 
Any ratio can't help simply because it is multiplied by 0. Check your 
cfstats.

24.04.12 09:54, crypto five написав(ла):
> Thank you Vitalii.
>
> Looking at the Jonathan's answer to your patch I think it's probably 
> not my case. I see that LiveRatio is calculated in my case, but 
> calculations look strange:
>
> WARN [MemoryMeter:1] 2012-04-23 23:29:48,430 Memtable.java (line 181) 
> setting live ratio to maximum of 64 instead of Infinity
>  INFO [MemoryMeter:1] 2012-04-23 23:29:48,432 Memtable.java (line 186) 
> CFS(Keyspace='lexems', ColumnFamily='countersCF') liveRatio is 64.0 
> (just-counted was 64.0).  calculation took 63355ms for 0 columns
>
> Looking at the comments in the code: "If it gets higher than 64 
> something is probably broken.", looks like it's probably the problem.
> Not sure how to investigate it.
>
> 2012/4/23 Віталій Тимчишин <tivv00@gmail.com <mailto:tivv00@gmail.com>>
>
>     See https://issues.apache.org/jira/browse/CASSANDRA-3741
>     I did post a fix there that helped me.
>
>
>     2012/4/24 crypto five <cryptofive@gmail.com
>     <mailto:cryptofive@gmail.com>>
>
>         Hi,
>
>         I have 50 millions of rows in column family on 4G RAM box. I
>         allocatedf 2GB to cassandra.
>         I have program which is traversing this CF and cleaning some
>         data there, it generates about 20k delete statements per second.
>         After about of 3 millions deletions cassandra stops responding
>         to queries: it doesn't react to CLI, nodetool etc.
>         I see in the logs that it tries to free some memory but can't
>         even if I wait whole day.
>         Also I see following in  the logs:
>
>         INFO [ScheduledTasks:1] 2012-04-23 18:38:13,333
>         StorageService.java (line 2647) Unable to reduce heap usage
>         since there are no dirty column families
>
>         When I am looking at memory dump I see that memory goes to
>         ConcurrentSkipListMap(10%), HeapByteBuffer(13%),
>         DecoratedKey(6%), int[](6%), BigInteger(8.2%),
>         ConcurrentSkipListMap$HeadIndex(7.2%), ColumnFamily(6.5%),
>         ThreadSafeSortedColumns(13.7%), long[](5.9%).
>
>         What can I do to make cassandra stop dying?
>         Why it can't free the memory?
>         Any ideas?
>
>         Thank you.
>
>
>
>
>     -- 
>     Best regards,
>      Vitalii Tymchyshyn
>
>


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