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From Michael Theroux <>
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,

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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