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Posted to user@cassandra.apache.org by "B. Todd Burruss" <bb...@real.com> on 2010/07/14 20:43:16 UTC
node down window
there is a window of time from when a node goes down and when the rest
of the cluster actually realizes that it is down.
what happens to writes during this time frame? does hinted handoff
record these writes and then "handoff" when the down node returns? or
does hinted handoff not kick in until the cluster realizes the node is
down?
... is the only way these missed writes are repaired is through read
repair and/or manually kicking off "nodetool repair"?
thx
Re: node down window
Posted by Jonathan Ellis <jb...@gmail.com>.
Coordination in a distributed system is difficult. I don't think we
can fix HH's existing edge cases, without introducing other more
complicated edge cases.
So weekly-or-so repair will remain a common maintenance task for the
forseeable future.
On Wed, Jul 14, 2010 at 4:17 PM, B. Todd Burruss <bb...@real.com> wrote:
> thx, but disappointing :)
>
> is this just something we have to live with and periodically "repair"
> the nodes? or is there future work to tighten up the window?
>
> thx
>
>
> On Wed, 2010-07-14 at 12:13 -0700, Jonathan Ellis wrote:
>> On Wed, Jul 14, 2010 at 1:43 PM, B. Todd Burruss <bb...@real.com> wrote:
>> > there is a window of time from when a node goes down and when the rest
>> > of the cluster actually realizes that it is down.
>> >
>> > what happens to writes during this time frame? does hinted handoff
>> > record these writes and then "handoff" when the down node returns? or
>> > does hinted handoff not kick in until the cluster realizes the node is
>> > down?
>>
>> the latter.
>>
>> > ... is the only way these missed writes are repaired is through read
>> > repair and/or manually kicking off "nodetool repair"?
>>
>> yes.
>>
>
>
>
--
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano, the source for professional Cassandra support
http://riptano.com
Re: node down window
Posted by "B. Todd Burruss" <bb...@real.com>.
thx, but disappointing :)
is this just something we have to live with and periodically "repair"
the nodes? or is there future work to tighten up the window?
thx
On Wed, 2010-07-14 at 12:13 -0700, Jonathan Ellis wrote:
> On Wed, Jul 14, 2010 at 1:43 PM, B. Todd Burruss <bb...@real.com> wrote:
> > there is a window of time from when a node goes down and when the rest
> > of the cluster actually realizes that it is down.
> >
> > what happens to writes during this time frame? does hinted handoff
> > record these writes and then "handoff" when the down node returns? or
> > does hinted handoff not kick in until the cluster realizes the node is
> > down?
>
> the latter.
>
> > ... is the only way these missed writes are repaired is through read
> > repair and/or manually kicking off "nodetool repair"?
>
> yes.
>
Re: node down window
Posted by Jonathan Ellis <jb...@gmail.com>.
On Wed, Jul 14, 2010 at 1:43 PM, B. Todd Burruss <bb...@real.com> wrote:
> there is a window of time from when a node goes down and when the rest
> of the cluster actually realizes that it is down.
>
> what happens to writes during this time frame? does hinted handoff
> record these writes and then "handoff" when the down node returns? or
> does hinted handoff not kick in until the cluster realizes the node is
> down?
the latter.
> ... is the only way these missed writes are repaired is through read
> repair and/or manually kicking off "nodetool repair"?
yes.
--
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano, the source for professional Cassandra support
http://riptano.com