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From Bryan Talbot <btal...@aeriagames.com>
Subject Re: disabling bloomfilter not working? or did I do this wrong?
Date Fri, 22 Feb 2013 23:10:26 GMT
I see from your read and write count that your nreldata CF has nearly equal
number of reads as writes.  I would expect that disabling your bloom filter
is going to hurt your read performance quite a bit.

Also, beware that disabling your bloom filter may also cause tombstoned
rows to never be deleted, so if you delete all columns explicitly or use
TTL, your data may grow more than your expect.
https://issues.apache.org/jira/browse/CASSANDRA-5182

-Bryan




On Fri, Feb 22, 2013 at 11:59 AM, Hiller, Dean <Dean.Hiller@nrel.gov> wrote:

> Thanks, but I found out it is still running.  It looks like I have about a
> 5 hour wait left for my upgradesstables(waited 4 hours already).  I will
> check the bloomfilter after that.
>
> Out of curiosity, if I had much wider rows (ie. < 900k) per row, will
> compaction run faster(errrrā€¦upgradesstables) at all or would it basically
> run at the same speed.
>
> I guess what I am wondering is 9 hours a normal compaction time for 130gb
> of data?
>
> Thanks,
> Dean
>
> From: aaron morton <aaron@thelastpickle.com<mailto:aaron@thelastpickle.com
> >>
> Reply-To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" <
> user@cassandra.apache.org<mailto:user@cassandra.apache.org>>
> Date: Friday, February 22, 2013 10:29 AM
> To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" <
> user@cassandra.apache.org<mailto:user@cassandra.apache.org>>
> Subject: Re: disabling bloomfilter not working? or did I do this wrong?
>
> Bloom Filter Space Used: 2318392048
> Just to be sane do a quick check of the -Filter.db files on disk for this
> CF.
> If they are very small try a restart on the node.
>
> Number of Keys (estimate): 1249133696
> Hey a billion rows on a node, what an age we live in :)
>
> Cheers
>
> -----------------
> Aaron Morton
> Freelance Cassandra Developer
> New Zealand
>
> @aaronmorton
> http://www.thelastpickle.com
>
> On 23/02/2013, at 4:35 AM, "Hiller, Dean" <Dean.Hiller@nrel.gov<mailto:
> Dean.Hiller@nrel.gov>> wrote:
>
> So in the cli, I ran
>
> update column family nreldata with bloom_filter_fp_chance=1.0;
>
> Then I ran
>
> nodetool upgradesstables databus5 nreldata;
>
> But my bloom filter size is still around 2gig(and I want to free up this
> heap)!!!! According to nodetool cfstats commandā€¦
>
> Column Family: nreldata
> SSTable count: 10
> Space used (live): 96841497731
> Space used (total): 96841497731
> Number of Keys (estimate): 1249133696
> Memtable Columns Count: 7066
> Memtable Data Size: 4286174
> Memtable Switch Count: 924
> Read Count: 19087150
> Read Latency: 0.595 ms.
> Write Count: 21281994
> Write Latency: 0.013 ms.
> Pending Tasks: 0
> Bloom Filter False Postives: 974393
> Bloom Filter False Ratio: 0.99998
> Bloom Filter Space Used: 2318392048
> Compacted row minimum size: 73
> Compacted row maximum size: 446
> Compacted row mean size: 143
>
>
>
>

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