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From Nate McCall <n...@thelastpickle.com>
Subject Re: LTCS Strategy Resulting in multiple SSTables
Date Tue, 15 Sep 2015 21:53:49 GMT
That's an early 2.1/known buggy version. There have been several issues
fixed since which could cause that behavior. Most likely
https://issues.apache.org/jira/browse/CASSANDRA-9592 ?

Upgrade to 2.1.9 and see if the problem persists.

On Tue, Sep 15, 2015 at 8:31 AM, Saladi Naidu <naidusp2002@yahoo.com> wrote:

> We are on 2.1.2 and planning to upgrade to 2.1.9
>
> Naidu Saladi
>
> ------------------------------
> *From:* Marcus Eriksson <krummas@gmail.com>
> *To:* user@cassandra.apache.org; Saladi Naidu <naidusp2002@yahoo.com>
> *Sent:* Tuesday, September 15, 2015 1:53 AM
> *Subject:* Re: LTCS Strategy Resulting in multiple SSTables
>
> if you are on Cassandra 2.2, it is probably this:
> https://issues.apache.org/jira/browse/CASSANDRA-10270
>
>
>
> On Tue, Sep 15, 2015 at 4:37 AM, Saladi Naidu <naidusp2002@yahoo.com>
> wrote:
>
> We are using Level Tiered Compaction Strategy on a Column Family. Below
> are CFSTATS from two nodes in same cluster, one node has 880 SStables in L0
> whereas one node just has 1 SSTable in L0. In the node where there are
> multiple SStables, all of them are small size and created same time stamp.
> We ran Compaction, it did not result in much change, node remained with
> huge number of SStables. Due to this large number of SSTables, Read
> performance is being impacted
>
> In same cluster, under same keyspace, we are observing this discrepancy in
> other column families as well. What is going wrong? What is the solution to
> fix this
>
> *---*NODE1*---*
> *                Table: category_ranking_dedup*
> *                                SSTable count: 1*
> *                                SSTables in each level: [1, 0, 0, 0, 0,
> 0, 0, 0, 0]*
> *                                Space used (live): 2012037*
> *                                Space used (total): 2012037*
> *                                Space used by snapshots (total): 0*
> *                                SSTable Compression Ratio:
> 0.07677216119569073*
> *                                Memtable cell count: 990*
> *                                Memtable data size: 32082*
> *                                Memtable switch count: 11*
> *                                Local read count: 2842*
> *                                Local read latency: 3.215 ms*
> *                                Local write count: 18309*
> *                                Local write latency: 5.008 ms*
> *                                Pending flushes: 0*
> *                                Bloom filter false positives: 0*
> *                                Bloom filter false ratio: 0.00000*
> *                                Bloom filter space used: 816*
> *                                Compacted partition minimum bytes: 87*
> *                                Compacted partition maximum bytes:
> 25109160*
> *                                Compacted partition mean bytes: 22844*
> *                                Average live cells per slice (last five
> minutes): 338.84588318085855*
> *                                Maximum live cells per slice (last five
> minutes): 10002.0*
> *                                Average tombstones per slice (last five
> minutes): 36.53307529908515*
> *                                Maximum tombstones per slice (last five
> minutes): 36895.0*
>
> *----NODE2---  *
> *Table: category_ranking_dedup*
> *                                SSTable count: 808*
> *                                SSTables in each level: [808/4, 0, 0, 0,
> 0, 0, 0, 0, 0]*
> *                                Space used (live): 291641980*
> *                                Space used (total): 291641980*
> *                                Space used by snapshots (total): 0*
> *                                SSTable Compression Ratio:
> 0.1431106696818256*
> *                                Memtable cell count: 4365293*
> *                                Memtable data size: 3742375*
> *                                Memtable switch count: 44*
> *                                Local read count: 2061*
> *                                Local read latency: 31.983 ms*
> *                                Local write count: 30096*
> *                                Local write latency: 27.449 ms*
> *                                Pending flushes: 0*
> *                                Bloom filter false positives: 0*
> *                                Bloom filter false ratio: 0.00000*
> *                                Bloom filter space used: 54544*
> *                                Compacted partition minimum bytes: 87*
> *                                Compacted partition maximum bytes:
> 25109160*
> *                                Compacted partition mean bytes: 634491*
> *                                Average live cells per slice (last five
> minutes): 416.1780688985929*
> *                                Maximum live cells per slice (last five
> minutes): 10002.0*
> *                                Average tombstones per slice (last five
> minutes): 45.11547792333818*
> *                                Maximum tombstones per slice (last five
> minutes): 36895.0*
>
>
>
>
> Naidu Saladi
>
>
>
>
>


-- 
-----------------
Nate McCall
Austin, TX
@zznate

Co-Founder & Sr. Technical Consultant
Apache Cassandra Consulting
http://www.thelastpickle.com

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