I think it makes sense to move to HDFS if it is reliable (can survive
continuous ingest and the agitator) and performs well. Also, I am very
curious about what the performance differences are.  It would be nice
to do some test.

On Mon, Jan 30, 2012 at 10:48 AM, Aaron Cordova
<[email protected]> wrote:
> At the Hbase vs Accumulo deathmatch the other night Todd elucidated that 
> Hbase's write-ahead log is in HDFS and benefits somewhat thereby. He 
> neglected to mention that for years until HDFS append() was available Hbase 
> just LOST data while Accumulo didn't .. but he was talking about the current 
> state of affairs so, whatever.
>
> The question now is, does it make any sense to look at HDFS as a place to 
> store Accumulo's write-ahead log? I remember that BigTable used two write 
> streams (each of which is transparently replicated by HDFS) and switched 
> between them to avoid performance hiccups, so it does sound like a critical 
> part of the overall performance. Such a big change would belong probably in 
> 1.6 or later ... But there may be reasons to never use HDFS and to always use 
> a separately maintained subsystem.
>
> Any one care to lay out the arguments for staying with a separate subsystem? 
> I think we know the arguments for using HDFS.
>
> Aaron
>

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