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From Roshan Dawrani <roshandawr...@gmail.com>
Subject Re: Performance degradation observed through embedded cassandra server - pointers needed
Date Fri, 23 Sep 2011 07:59:29 GMT
Thanks for sharing your inputs, Edward. Some comments inline below:

On Thu, Sep 22, 2011 at 7:31 PM, Edward Capriolo <edlinuxguru@gmail.com>wrote:
>
>
>> 1) Should should try to dig in an determine why the truncate is slower.
> Look for related jira issues on truncation.
>

I should give it a try. I thought I might get some readymade pointers from
people already knowing about 0.7.2 / 0.8.5 differences on whether our
approach to truncate every test has gone even worse due to some changes in
that area.


> Cassandra had some re-entrant code you could fork a JVM each test and use
> the CassandraServiceDataCleaner. (However multiple startups could end up
> causing more overhead then the truncation)
>
> I avoid this problem by using a different column family and or a different
> keyspaces for all my unit tests in a single class. Each class bring up a new
> embedded cluster and uses the data cleaner to sanitize the data directories.
> So essentially I never call truncate.
>

In both these approaches, won't I need to re-build the schema for every test
too? Certainly in the 2nd case, if I end up creating new keyspace or
different column families for each test. I am not sure what I will gain
there in terms of performance. I was hoping data truncation leaving schema
there would be faster than that.

-- 
Roshan
Blog: http://roshandawrani.wordpress.com/
Twitter: @roshandawrani <http://twitter.com/roshandawrani>
Skype: roshandawrani

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