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From Ted Yu <yuzhih...@gmail.com>
Subject Re: modify prePut() behavior
Date Fri, 07 Feb 2014 19:09:16 GMT
bq. However, calling bypass() seems to have no effect.

In HRegion :

          if (coprocessorHost.prePut((Put) m, walEdit, m.getWriteToWAL())) {
            // pre hook says skip this Put
            // mark as success and skip in doMiniBatchMutation
            batchOp.retCodeDetails[i] = OperationStatus.SUCCESS;

Can you be a bit more specific about your observation ?

Cheers


On Fri, Feb 7, 2014 at 11:02 AM, aa a <ameet.chaubal@gmail.com> wrote:

> Hi,
>
> I'd like to perform a put but have it succeed only if certain conditions
> based on values of some columns are met.
> I am on 0.94.6
>
> my first option was:
> write a prePut() Observer, perform the checks in there and then call a
> bypass() if needed.
> However, calling bypass() seems to have no effect. I thought that bypass()
> would cause HBase to not perform the put.
> Is that not correct?
>
> second option:
> write a preCheckAndPut() and perform the validations there. problem is that
> I have been running the process via a map/reduce and using
> TableMapReduceUtil.initTableReducerJob(
>         TABLE_NAME,
>         null,
>         job);
> And there seems to be no way to tell this to use "checkAndPut" instead of
> "put", is there?
>
>
> third option:
> I could try to do my own htable.checkAndPut from the mapper. However, since
> I am on a kerberized cluster, I am not able to get an htable in the setup()
> method of the mapper.
> GSS initiate failed [Caused by GSSException: No valid credentials provided
> (Mechanism level: Failed to find any Kerberos tgt)]
>  trying to perform UserGroupInformation.loginUserFromKeytab() fails too;
> I  get Caused by: javax.security.auth.login.LoginException: Unable to
> obtain password from user
> So I am not able to do any htable call from the mapper.
>
> The only M/R that has worked for me to read from HDFS text file as source
> and write to HBase sink is TableMapReduceUtil.initTableReducerJob() with
> null for reducer class.
>
> Any thoughts?
>
> Thank you much in advance
>
> ameet
>

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