Thanks. I will set the debug mode and see/share if it shows any relevant info.
The smaller batches of 20 or so column mutations had been working fine. After merging, the total # of mutations across all CFs must not be crossing 60-70. The problem is that it is not slow - it seems just hung there. --------------------------------------------------- Sent from BlackBerry -----Original Message----- From: Nate McCall <n...@datastax.com> Date: Thu, 17 Feb 2011 14:37:53 To: Roshan Dawrani<roshandawr...@gmail.com> Cc: <hector-us...@googlegroups.com>; <user@cassandra.apache.org> Subject: Re: Updating/inserting into multiple column families using one mutator batch log4-server.properties in the conf directory of cassandra (requires a restart) or via JMX through JConsole or similar on o.a.c.service.StorageService#setLog4jLevel Is there a threshold under which you can successfully insert in batch mode? Even with something low like 10 entries? On Thu, Feb 17, 2011 at 2:29 PM, Roshan Dawrani <roshandawr...@gmail.com> wrote: > 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 <n...@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 <roshandawr...@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 >> > >> > > >
