incubator-cassandra-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Ramzi Rabah <>
Subject Re: Small HintedHanoffManager improvement?
Date Wed, 23 Dec 2009 03:26:24 GMT
Cool thanks for the explanation. It might happen if a delete hint for
that entry was sent after the data hint was submitted to that node so
both hint and the delete hint are sent to the same node leading to an
empty CF (which is a very unlikely scenario), but it does seem that
the code handles it gracefully (it does write it to the commitlog, not
to the memtable, but then when you recover from the commitlog, I
believe the code ignores the entry).

On Tue, Dec 22, 2009 at 8:19 AM, Jonathan Ellis <> wrote:
> On Mon, Dec 21, 2009 at 12:46 PM, Ramzi Rabah <> wrote:
>> It seems that we still send a row mutation even if the cf of the row
>> is null.
> It should never happen, and if it does it's harmless, so adding a
> special case for it is counterproductive.
>> On a different note, I have a few questions about HHOM design.
>> HintedHandOffManager seems to send the whole CF for a key, even if the
>> only thing that changed was a value in 1 single column.
> Only the changed parts are written to hint nodes in the first place.
>> And one last question about HHOM, since the node that is handling the
>> Hint might not be (and is probably not) one of the replicas if I
>> understood the code correctly, Will the data written to it ever be
>> cleaned, if I issue a delete later on down the line?
> Hinted data is removed by cleanup operations.
> -Jonathan

View raw message