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From Nick Bailey <>
Subject Re: Cleanup in a write-only environment
Date Wed, 30 Nov 2011 21:20:30 GMT
I believe you are mis-understanding what cleanup does. Cleanup is used
to remove data from a node that the node no longer owns. For example
when you move a node in the ring, it changes responsibility and gets
new data, but does not automatically delete the data it used to be
responsible for but no longer is. In this situation, you run cleanup
to delete all of that old data.

Data that has been deleted/expired will get removed automatically as
compaction runs.

On Wed, Nov 30, 2011 at 7:24 AM, David McNelis
<> wrote:
> In my understanding Cleanup is meant to help clear out data that has  been
> removed.  If you have an environment where data is only ever added (the case
> for the production system I'm working with), is there a point to automating
> cleanup?   I understand that if we were to ever purge a segment of data from
> our cluster we'd certainly want to run it, or after added a new node and
> adjusting the tokens.
> So I want to make sure I'm not missing something here and that there  would
> be other  reasons to run cleanup regularly?
> --
> David McNelis
> Lead Software Engineer
> Agentis Energy
> c: 219.384.5143
> A Smart Grid technology company focused on helping consumers of energy
> control an often under-managed resource.

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