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Posted to user@cassandra.apache.org by Sean Bridges <se...@gmail.com> on 2014/10/16 19:20:03 UTC
are all files for an sstable immutable?
Hello,
I thought an sstable was immutable once written to disk. Before upgrading
from 1.2.18 to 2.0.10 we took a snapshot of our sstables. Now when I
compare the files in the snaphot dir and the original files, the Summary.db
files have a newer modified date, and the file sizes have changed.
Thanks,
Sean
Re: are all files for an sstable immutable?
Posted by Sean Bridges <se...@gmail.com>.
Thanks Tyler, that explains it.
Sean
On Thu, Oct 16, 2014 at 10:40 AM, Tyler Hobbs <ty...@datastax.com> wrote:
> The summary files are immutable, but can be replaced periodically. See
> https://issues.apache.org/jira/browse/CASSANDRA-5519 for more details.
>
> The summary files aren't particularly important, they're primarily an
> optimization for startup time.
>
> On Thu, Oct 16, 2014 at 12:20 PM, Sean Bridges <se...@gmail.com>
> wrote:
>
>> Hello,
>>
>> I thought an sstable was immutable once written to disk. Before
>> upgrading from 1.2.18 to 2.0.10 we took a snapshot of our sstables. Now
>> when I compare the files in the snaphot dir and the original files, the
>> Summary.db files have a newer modified date, and the file sizes have
>> changed.
>>
>> Thanks,
>>
>> Sean
>>
>
>
>
> --
> Tyler Hobbs
> DataStax <http://datastax.com/>
>
Re: are all files for an sstable immutable?
Posted by Robert Coli <rc...@eventbrite.com>.
On Thu, Oct 16, 2014 at 10:40 AM, Tyler Hobbs <ty...@datastax.com> wrote:
> The summary files are immutable, but can be replaced periodically. See
> https://issues.apache.org/jira/browse/CASSANDRA-5519 for more details.
>
> The summary files aren't particularly important, they're primarily an
> optimization for startup time.
>
Users of tablesnap will notice that this means that they are not backed up
in the default config. I believe there's an open bug, but one can
workaround by adding in_move_to (iirc) to the list of events which
tablesnap is watching the data dir for.
But as thobbs says, it doesn't matter if they're not backed up, they are an
optimization and are easy (but somewhat expensive) to regenerate.
=Rob
Re: are all files for an sstable immutable?
Posted by Tyler Hobbs <ty...@datastax.com>.
The summary files are immutable, but can be replaced periodically. See
https://issues.apache.org/jira/browse/CASSANDRA-5519 for more details.
The summary files aren't particularly important, they're primarily an
optimization for startup time.
On Thu, Oct 16, 2014 at 12:20 PM, Sean Bridges <se...@gmail.com>
wrote:
> Hello,
>
> I thought an sstable was immutable once written to disk. Before upgrading
> from 1.2.18 to 2.0.10 we took a snapshot of our sstables. Now when I
> compare the files in the snaphot dir and the original files, the Summary.db
> files have a newer modified date, and the file sizes have changed.
>
> Thanks,
>
> Sean
>
--
Tyler Hobbs
DataStax <http://datastax.com/>