Hi, For our Grails + Cassandra application's clean-DB-for-every-test needs, we finally went back from using costly "truncate" calls to "range-scans-and-delete" approach, and found such a great different between the performance of the two approaches, that wrote a small blog post here about it: "Grails, Cassandra: Giving each test a clean DB to work with<http://roshandawrani.wordpress.com/2011/09/30/grails-cassandra-giving-each-test-a-clean-db-to-work-with/>" For someone in a similar situation, it may present an alternative.
Cheers. On Fri, Sep 23, 2011 at 1:29 PM, Roshan Dawrani <roshandawr...@gmail.com>wrote: > Thanks for sharing your inputs, Edward. Some comments inline below: > > On Thu, Sep 22, 2011 at 7:31 PM, Edward Capriolo <edlinuxg...@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 > > -- Roshan Blog: http://roshandawrani.wordpress.com/ Twitter: @roshandawrani <http://twitter.com/roshandawrani> Skype: roshandawrani
