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From William Slacum <>
Subject Re: Accumulo and file locality
Date Mon, 25 Jun 2012 17:20:55 GMT
The loggers will write to local disk, however, the TabletServer will
write out files to HDFS during major and minor compactions.

I don't know how complex the tablet assignment algorithm is, but it's
safe to assume that if your tablet spans multiple HDFS blocks, a
TServer will, in all likelihood, only be hosting 1 HDFS block of a
given tablet at any given time, and do fetches for other HDFS (and
RFile) blocks as the need arises. There is a caching mechanism for
holding on to RFile blocks.

On Mon, Jun 25, 2012 at 10:13 AM, Cardon, Tejay E
<> wrote:
> All,
>                 If I understand things correctly, when an Accumulo tablet
> server writes data, things are organized such that those writes go to the
> local disk (ie each tablet server writes and reads data to/from the disk
> local to that server).  Is this correct?  And if so, then is it correct to
> assume that every tablet server should run on an HDFS data node?  Or am I
> completely off base here?
> Thanks,
> Tejay Cardon

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