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From Robert Newson <robert.new...@gmail.com>
Subject Re: data recovery tool progress
Date Tue, 10 Aug 2010 17:59:33 GMT
I verified the new code's ability to repair the testwritesdb. system
load was smooth from start to finish.

I started a further test on a different (healthy) database and system
load was severe again, just collecting the roots (the lost+found db
was not yet created when I aborted the attempt). I suspect the fact
that it's healthy is the issue, so if I'm right, perhaps a warning is
useful.

B.



On Tue, Aug 10, 2010 at 6:53 PM, Adam Kocoloski <kocolosk@apache.org> wrote:
> Another update.  This morning I took a different tack and, rather than try to find root
nodes, I just looked for all kv_nodes in the file and treated each of those as a separate
virtual DB to be replicated.  This reduces the algorithmic complexity of the repair, and
it looks like testwritesdb repairs in ~30 minutes or so.  Also, this method results in the
lost+found DB containing every document, not just the missing ones.
>
> My branch does not currently include Randall's parallelization of the replications.  It's
still CPU-limited, so that may be a worthwhile optimization.  On the other hand, I think
we may be reaching a stage at which performance for this repair tool is 'good enough', and
pmaps can make error handling a bit dicey.
>
> In short, I think this tool is now in good shape.
>
> http://github.com/kocolosk/couchdb/tree/db_repair
>

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