got it! thanks a lot for the explanation! On Wed, Aug 24, 2011 at 1:06 AM, Edward Capriolo <edlinuxg...@gmail.com>wrote:
> > On Tue, Aug 23, 2011 at 11:56 AM, Sam Overton <sover...@acunu.com> wrote: > >> On 21 August 2011 12:34, Yan Chunlu <springri...@gmail.com> wrote: >> >>> since "nodetool cleanup" could remove hinted handoff, will it cause the >>> data loss? >> >> >> Hi Yan, >> >> Hints are not guaranteed to be delivered and "nodetool cleanup" is one of >> the reasons for that. This will only cause data-loss if you are writing at >> CL.ANY where a hint counts as a write. If you are writing at CL.ONE or above >> then at least one replica must receive the data for the write to succeed, so >> losing hints will not cause data-loss. >> >> If a hint is not delivered then the replica to which it was intended will >> become consistent after a read-repair, or after manual anti-entropy repair. >> >> Sam >> >> -- >> Sam Overton >> Acunu | http://www.acunu.com | @acunu >> > > If you run nodetool tpstats on each node in your cluster and ensure none of > them have an active or pending threads in the Hinted stage no hints are > currently being delivered. But as pointed out above Hinted Handoff is a best > effort system. >
