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From Rob Coli <rc...@digg.com>
Subject Re: Cassandra disk space utilization WAY higher than I would expect
Date Wed, 07 Jul 2010 17:37:25 GMT
On 7/7/10 10:10 AM, Julie wrote:

> This doesn't explain why 30 GB of data is taking up 106 GB of disk 24 hours
> after all writes have completed.  Compactions should be complete, no?

Is your workload straight INSERT or does it contain UPDATE and/or 
DELETE? If your workload contains UPDATE/DELETE and GCGraceSeconds (10 
days by default) hasn't passed, you might have a non-trivial number of 
tombstone rows. Only major compactions clean up tombstones in the 
current implementation and even given improvements [1] they will always 
be necessary in some cases.

=Rob

[1] https://issues.apache.org/jira/browse/CASSANDRA-1074


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