Re: Cluster-wide pause

[Jonathan Ellis <jb...@gmail.com>]

use a larger heap or throttle your writes

On Wed, Jun 30, 2010 at 12:12 PM, Steve Lihn <st...@gmail.com> wrote:
> Jon,
> I am experimenting writing 8 million rows into Cassandra and also
> experienced some random timeouts, even with 10-second timeout parameter.
> How do I avoid such timeout at all cost? (I.e. At this time, my priority is
> to finish the end-to-end test. Don't want the program to fail at all.)
> This is a one-node server with ms1G and mx2GB. The rest in cassandra.in.sh
> are default I think.
>
> Steve
>
> On Wed, Jun 30, 2010 at 1:58 AM, Jonathan Ellis <jb...@gmail.com> wrote:
>>
>> You could be seeing GC pauses. Did you increase the heap size you gave
>> Cassandra, when you increased your VM size?
>>
>> On Tue, Jun 29, 2010 at 11:57 AM, Oren Benjamin <or...@clearspring.com>
>> wrote:
>> > Hi all - first timer here.
>> >
>> > I'm experimenting with Cassandra on Rackspace Cloud.  Started with 4GB
>> > nodes and saw read latency spikes while streaming was taking place, so I
>> > increased to 8GB to see if limited memory was the issue.  Now I'm seeing
>> > very strange behavior during any period that writes are taking place.  The
>> > entire (6 node) cluster seems to pause for periods of as much as 5-8 sec.
>> >  By that I mean all the stats (cpu, disk, network IO monitored via dstat)
>> > drop to zero or near zero on all nodes simultaneously.  Does anyone have
>> > experience with Cassandra on Rackspace or any idea what's going on here?
>> >
>> > The pauses are short enough that it's difficult to introspect the
>> > application and determine what it's doing during the pause, but long enough
>> > to cause unacceptable latency for any service built on top of it.
>> >
>> > Any ideas or debugging methods would be greatly appreciated,
>> >
>> >  -- Oren
>>
>>
>>
>> --
>> Jonathan Ellis
>> Project Chair, Apache Cassandra
>> co-founder of Riptano, the source for professional Cassandra support
>> http://riptano.com
>
>



-- 
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano, the source for professional Cassandra support
http://riptano.com