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From Michael Theroux <mthero...@yahoo.com>
Subject Re: Issue with leveled compaction and data migration
Date Fri, 13 Sep 2013 11:27:04 GMT
Another question on this topic.

Would forcing the table to relevel help this situation?  I believe the process to do this
on 1.1.X would be to stop cassandra, remove .json file, and restart cassandra.  Is this true?

Any help would be appreciated,
Thanks,
-Mike

On Sep 12, 2013, at 6:47 PM, Michael Theroux wrote:

> Hello,
> 
> We've been undergoing a migration on Cassandra 1.1.9 where we are combining two column
families.  We are incrementally moving data from one column family into another, where the
columns in a row in the source column family are being appended to columns in a row in the
target column family.  Both column families are using leveled compaction, and both column
families have over 100 million rows.  
> 
> However, our bloom filters on the target column family grow dramatically (less than double)
after converting less than 1/4 of the data.  I assume this is because new changes are not
being compacted with older changes, although I thought leveled compaction would mitigate this
for me. Any advice on what we can do to control our bloom filter growth during this migration?
> 
> Appreciate the help,
> Thanks,
> -Mike


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