Hi Lars: This helps a lot! Thanks!
Best Regards, Jerry Sent from my iPad (sorry for spelling mistakes) On 2012-08-07, at 20:30, lars hofhansl <[email protected]> wrote: > I filed HBASE-6522. It is a trivial change to make locks and leases available > to coprocessors. > So checkAndSet type operations can then be implemented via coprocessor > endpoints: lock row, check, fail or update, unlock row. > > Since the patch is so simple I'll commit that soon (to 0.94.2 and 0.96) > > > -- Lars > > ________________________________ > From: lars hofhansl <[email protected]> > To: "[email protected]" <[email protected]> > Sent: Tuesday, August 7, 2012 8:55 AM > Subject: Re: CheckAndAppend Feature > > There is no such functionality currently, and there is no good way to > simulate that. > > Currently that cannot even be done with a coprocessor endpoint, because > region coprocessors have no way to create a region lock (just checked the > code). > (That is something we have to change I think - I will create an issue once > the Jira system is back from the walk in the park). > > -- Lars > > > ----- Original Message ----- > From: Jerry Lam <[email protected]> > To: user <[email protected]> > Cc: > Sent: Tuesday, August 7, 2012 8:22 AM > Subject: CheckAndAppend Feature > > Hi HBase community: > > I checked the HTable API, it has checkAndPut and checkAndDelete but I'm > looking for checkAndAppend. Is there a way to simulate similarly? > For instance, I want to check the last 32 bytes of a value (let assume that > it has 128 bytes in total) in a column before appending atomically some > values into it. > > Thanks! > > Jerry
