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From Roshan Dawrani <roshandawr...@gmail.com>
Subject Re: Updating/inserting into multiple column families using one mutator batch
Date Thu, 17 Feb 2011 20:29:45 GMT
Hi,

Thanks for replying.

I have kept an eye on the Cassandra logs as well as my app server logs, and
I didn't notice any unusual hector/casandra messages there.

Where can I configure to see cassandra logs in debug mode?

I am pretty sure I haven't touched the 500 mutations in a batch yet. What
could be other possibilities for it hanging? It's happening absolutely
consistently.

rgds,
Roshan

On Fri, Feb 18, 2011 at 1:50 AM, Nate McCall <nate@datastax.com> wrote:

> It is fine to use multiple coumn families via batch_mutate. The size
> of the batch itself will take some tunning. In what you are describing
> below, it will help watch the cassandra logs in debug mode to diagnose
> the issue.
>
> In general though, I think a good rule with batch_mutate is to start
> with 500 mutations (regardless of column families) and go up
> incrementally from there watching the logs and ideally memory
> consumption as you go.
>
> On Thu, Feb 17, 2011 at 2:11 PM, Roshan Dawrani <roshandawrani@gmail.com>
> wrote:
> > Hi,
> > Is it ok to update / insert into multiple column families (some regular,
> > some related super column families) using in one batch?
> >
> > I earlier had a few separates mutator.execute() calls hitting these CFs,
> but
> > I am trying to merge them into a bigger batch.
> > The issue I am facing is that the smaller batches used to get executed
> > perfectly, but with the combined one, the updates just hang !
> > I am not pin-pointing the issue anywhere at this time. I just want to
> know
> > if it is normal to update multiple CFs in a batch and if there is
> deadlock
> > situation that may arise if that is done.
> > --
> > Roshan
> > Blog: http://roshandawrani.wordpress.com/
> > Twitter: @roshandawrani
> > Skype: roshandawrani
> >
> >
>

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