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Subject Re: Recover from losing zookeeper data
Date Tue, 20 Dec 2011 22:08:25 GMT
> When you say all local ZK storage was deleted, do you mean you lost all
> the
> data in the version-2 directory, or deleted the zk ephemera?

Lost all data.

So I ended up just re-initializing Accumulo and re-ingesting data.  Thanks
for the suggestions everyone.  The is useful troubleshooting info to have

> If it's just the latter, than you may be able to roll-back to a earlier
> snapshot of your data.
> Clint
> On Tue, Dec 20, 2011 at 2:04 PM, Keith Turner <> wrote:
>> On Tue, Dec 20, 2011 at 1:50 PM, Adam Fuchs <>
>> wrote:
>> > I agree with John, but one caveat to his solution is that data you
>> have
>> > deleted could reappear through bulk loading files that are in the HDFS
>> > accumulo directory. This also implies that counts on aggregate tables
>> could
>> > be different after the operation. If your application is sensitive to
>> these
>> > things, then you might have to attempt to recreate the zookeeper data
>> by
>> > hand (or just start from scratch).
>> >
>> > Adam
>> >
>> What John proposed is the simplest solution.  Zookeeper holds table
>> name to table id map, table configuration, user information, and
>> information about the root tablet.  The most important info that it
>> contains w/ regards to actual data in accumulo is the write ahead logs
>> for the root tablet.  Except for the root table write ahead logs, the
>> !METADATA table is all on hdfs.  The !METADATA table contains all the
>> information about which tables use which files.  This information is
>> important for avoiding the problem that Adam mentioned.

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