cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From aaron morton <>
Subject Re: Strange delay in query
Date Wed, 14 Nov 2012 04:14:04 GMT
Minor compactions will still be triggered whenever a size tier gets 4+ sstables (for the default
compaction strategy). So it does not affect new data. 

It just takes longer for the biggest size tier to get to 4 files. So it takes longer to compact
the big output from the major compaction. 

Assuming your data roughly follows a generational model, where newer data is written to often
and older data is mostly read from. This can mean garbage hanging around in the big old file
and *potentially* slowing things down. 


Aaron Morton
Freelance Developer

On 14/11/2012, at 12:21 AM, André Cruz <> wrote:

> On Nov 13, 2012, at 8:54 AM, aaron morton <> wrote:
>>> I don't think that statement is accurate.
>> Which part ?
> Probably this part:
> "After running a major compaction, automatic minor compactions are no longer triggered,
frequently requiring you to manually run major compactions on a routine basis."
> From what I read what happens is that it takes a lot longer for minor compactions to
be triggered because 3 more files with the size equal to the compacted one have to be created?
> André

View raw message