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Posted to user@cassandra.apache.org by Oleg Dulin <ol...@gmail.com> on 2012/10/05 15:54:27 UTC
Re: rolling restart after gc_grace change
What if gc_grace_seconds is pretty low, say 2 mins, what happens with
nodetool repair ?
That wiki page below points at a bug that has been fixed long ago. Is
it still an issue if you don't run a repair within gc_grace_seconds ?
On 2012-01-09 10:02:49 +0000, aaron morton said:
> Nah, thats old style.
>
> gc_grace_seconds is a CF level setting now. Make the change with update
> column family in the CLI or your favorite client.
>
> Cheers
>
> -----------------
> Aaron Morton
> Freelance Developer
> @aaronmorton
> http://www.thelastpickle.com
>
> On 9/01/2012, at 9:33 PM, Igor wrote:
> Hi!
>
> On the
> http://wiki.apache.org/cassandra/Operations#Dealing_with_the_consequences_of_nodetool_repair_not_running_within_GCGraceSeconds
> you can read:
>
> "To minimize the amount of forgotten deletes, first increase
> GCGraceSeconds across the cluster (rolling restart required)"
>
> Rolling restart still required for 1.0.6?
--
Regards,
Oleg Dulin
NYC Java Big Data Engineer
http://www.olegdulin.com/
Re: rolling restart after gc_grace change
Posted by aaron morton <aa...@thelastpickle.com>.
> Is it still an issue if you don't run a repair within gc_grace_seconds ?
There is a potential issue.
You want to make sure the tombstones are distributed to all replicas *before* gc_grace_seconds has expired. If they are not you can have a case where some replicas compact and purge their tombstone (essentially a hard delete), while one replica keeps the original value. The result is data returning from the dead.
Cheers
-----------------
Aaron Morton
Freelance Developer
@aaronmorton
http://www.thelastpickle.com
On 6/10/2012, at 2:54 AM, Oleg Dulin <ol...@gmail.com> wrote:
> What if gc_grace_seconds is pretty low, say 2 mins, what happens with nodetool repair ?
>
> That wiki page below points at a bug that has been fixed long ago. Is it still an issue if you don't run a repair within gc_grace_seconds ?
>
> On 2012-01-09 10:02:49 +0000, aaron morton said:
>
> Nah, thats old style.
>
> gc_grace_seconds is a CF level setting now. Make the change with update column family in the CLI or your favorite client.
>
> Cheers
>
> -----------------
> Aaron Morton
> Freelance Developer
> @aaronmorton
> http://www.thelastpickle.com
>
> On 9/01/2012, at 9:33 PM, Igor wrote:
> Hi!
>
> On thehttp://wiki.apache.org/cassandra/Operations#Dealing_with_the_consequences_of_nodetool_repair_not_running_within_GCGraceSeconds you can read:
>
> "To minimize the amount of forgotten deletes, first increase GCGraceSeconds across the cluster (rolling restart required)"
>
> Rolling restart still required for 1.0.6?
>
>
> --
> Regards,
> Oleg Dulin
> NYC Java Big Data Engineer
> http://www.olegdulin.com/