incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Edward Capriolo <edlinuxg...@gmail.com>
Subject Re: heap usage
Date Fri, 15 Feb 2013 16:16:23 GMT
It is not going to be true for long that LCS does not require bloom filters.

https://issues.apache.org/jira/browse/CASSANDRA-5029

Apparently, without bloom filters there are issues.

On Fri, Feb 15, 2013 at 7:29 AM, Blake Manders <blake@crosspixel.net> wrote:
>
> You probably want to look at your bloom filters.  Be forewarned though,
> they're difficult to change; changes to bloom filter settings only apply to
> new SSTables, so they might not be noticeable until a few compactions have
> taken place.
>
> If that is your issue, and your usage model fits it, a good alternative to
> the slow propagation of higher miss rates is to switch to LCS (which doesn't
> use bloom filters), which won't require you to make the jump to 1.2.
>
>
> On Fri, Feb 15, 2013 at 4:06 AM, Reik Schatz <reik.schatz@gmail.com> wrote:
>>
>> Hi,
>>
>> recently we are hitting some OOM: Java heap space, so I was investigating
>> how the heap is used in Cassandra 1.2+
>>
>> We use the calculated 4G heap. Our cluster is 6 nodes, around 750 GB data
>> and a replication factor of 3. Row cache is disabled. All key cache and
>> memtable settings are left at default.
>>
>> Is the primary key index kept in heap memory? We have a bunch of keyspaces
>> and column families.
>>
>> Thanks,
>> Rik
>
>
>
>
> --
>
> Blake Manders | CTO
>
> Cross Pixel, Inc. | 494 8th Ave, Penthouse | NYC 10001
>
> Website: crosspixel.net
> Twitter: twitter.com/CrossPix

Mime
View raw message