incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jonathan Ellis <jbel...@gmail.com>
Subject Re: cassandra slows down after inserts
Date Mon, 13 Jul 2009 13:13:30 GMT
See the wiki page I linked.

On Mon, Jul 13, 2009 at 8:06 AM, rkmr.em@gmail.com<rkmr.em@gmail.com> wrote:
>
> how do i find out if JVM is GCing?
>
> On Sun, Jul 12, 2009 at 10:37 PM, Sandeep Tata <sandeep.tata@gmail.com>
> wrote:
>>
>> What hardware are you running one?
>
>  dual quadcore intel xeon 2.0 ghz, 32GB ram, and hardware raid config
> operating system is fedora core 9
>
>
>> How long does the slowdown last ?
>
> i stopped inserting data after slowdown starts, and it is still slow now
> after over 10 hours.
> however if i stop cassandra and start it, it becomes super fast immediately.
> till i insert another 100k or so rows when it becomes really slow again.
>
>
>>
>>  There are a few reasons for temporary slowdowns ... perhaps the JVM
>> started GCing?
>
> how do i find out if this is the cause?
>
>
>>
>> Cassandra spends time cleaning up the on-disk SSTables
>> in a process called compaction. This could cause the client to observe
>> a slowdown.
>>
>> Things you could try --
>> Reduce the Memtable size in the config files. (If GCing was the problem)
>> Increasing the number of SSTables written before compaction kicks in.
>
> can you tell me what numbers i should use?
>
> thanks!
>
>

Mime
View raw message