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From Keith Turner <>
Subject Re: better presplitting
Date Wed, 25 Jun 2014 20:50:23 GMT
I wrote a little utility to time splitting and subsequent balancing.  I
will post some numbers from running this on EC2

On Fri, Jun 20, 2014 at 2:58 PM, Sean Busbey <> wrote:

> One thing that jumped out from the most recent D4M paper was this quote:
>   One issue that was encountered is that after creating the pre-splits,
> they all started out on one server. Accumulo load balanced the splits
> across its servers at rate of ~50 splits/second, which is more than
> adequate for normal operation, but can take ~20 minutes for 50,000 pre-
> splits.[1]
> Do we already have an open ticket that would help this? I think maybe
> there's one about being able to presplit a table that is offline?
> I believe our recommended sweet spot is like 100-200 tablets per server
> (though I can't find the reference for *why* I believe this ATM), which
> means for clusters in the ~100s of nodes this would be in the ballpark for
> an expected number of pre-splits.
> [1]:  arXiv:1406.4923v1 [cs.DB]
> --
> Sean

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