incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From aaron morton <aa...@thelastpickle.com>
Subject Re: disabling bloomfilter not working? memory numbers don't add up?
Date Thu, 28 Feb 2013 18:30:16 GMT

> 1. Can I stop the node, delete the *Filter.db files and restart the node(is this safe)???
No. 

> 2. Why do I have 5 gig being eaten up by cassandra?  "nodetool info" memory 5.2Gig, key
cache:11 meg and row cache 0 bytes.   All bloomfilters are also small <1meg.
If this is the Heap memory reported by the JVM that all you can say is "since the server was
started it has allocated at least 5.2 GB of memory" it's not "there is 5.2GB of live memory
in use"

Cheers
-----------------
Aaron Morton
Freelance Cassandra Developer
New Zealand

@aaronmorton
http://www.thelastpickle.com

On 25/02/2013, at 9:32 AM, "Hiller, Dean" <Dean.Hiller@nrel.gov> wrote:

> Hmmmm, my upgrade completed and then I added node back in and ran my repair.  What is
weird is that my nreldata column family still shows 156Meg of memory still(down from 2 gig
though!!) in use and a false positive ratio of .99576 when I have the filter completely disabled(ie.
Set to 1.0).  I see the *Filter.db files on disk(and size approximately matches the in-memory
size).  I tried restarting the node as well.
> 
> 1. Can I stop the node, delete the *Filter.db files and restart the node(is this safe)???
> 2. Why do I have 5 gig being eaten up by cassandra?  "nodetool info" memory 5.2Gig, key
cache:11 meg and row cache 0 bytes.   All bloomfilters are also small <1meg.
> 
> Exception to #2 is I have nreldata still using 156MB for some reason but still no where
close to 5.2 gig that nodetool shows in use.
> 
> Thanks,
> Dean
> 
> 
> 
> 
> Bloom Filter Space Used: 2318392048<tel: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<http://www.thelastpickle.com/>
> 
> On 23/02/2013, at 4:35 AM, "Hiller, Dean" <Dean.Hiller@nrel.gov<mailto:Dean.Hiller@nrel.gov><mailto: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 command…
> 
> 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
> 
> 
> 
> 
> 
> 


Mime
View raw message