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From Redmumba <>
Subject Re: Customized Compaction Strategy: Dev Questions
Date Wed, 04 Jun 2014 17:03:26 GMT
Not quite; if I'm at say 90% disk usage, I'd like to drop the oldest
sstable rather than simply run out of space.

The problem with using TTLs is that I have to try and guess how much data
is being put in--since this is auditing data, the usage can vary wildly
depending on time of year, verbosity of auditing, etc..  I'd like to
maximize the disk space--not optimize the cleanup process.


On Wed, Jun 4, 2014 at 9:47 AM, Russell Bradberry <>

> You mean this:
> ?
> On June 4, 2014 at 12:42:33 PM, Redmumba ( wrote:
>  Good morning!
> I've asked (and seen other people ask) about the ability to drop old
> sstables, basically creating a FIFO-like clean-up process.  Since we're
> using Cassandra as an auditing system, this is particularly appealing to us
> because it means we can maximize the amount of auditing data we can keep
> while still allowing Cassandra to clear old data automatically.
> My idea is this: perform compaction based on the range of dates available
> in the sstable (or just metadata about when it was created).  For example,
> a major compaction could create a combined sstable per day--so that, say,
> 60 days of data after a major compaction would contain 60 sstables.
> My question then is, will this be possible by simply implementing a
> separate AbstractCompactionStrategy?  Does this sound feasilble at all?
> Based on the implementation of Size and Leveled strategies, it looks like I
> would have the ability to control what and how things get compacted, but I
> wanted to verify before putting time into it.
> Thank you so much for your time!
> Andrew

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