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From Alex Baranau <alex.barano...@gmail.com>
Subject Re: sync on writes
Date Wed, 01 Aug 2012 13:16:05 GMT
I believe that this is *not default*, but *current* implementation of
sync(). I.e. (please correct me if I'm wrong) n-way write approach is not
available yet.
You might confuse it with the fact that by default, sync() is called on
every edit. And you can change it by using "deferred log flushing". Either
way, sync() is going to be a pipelined write.

There's an explanation of benefits of pipelined and n-way writes there in
the book (p337), it's not just about which approach provides better
 durability of saved edits. Both of them do. But both can take different
time to execute and utilize network differently: pipelined *may* be slower
but can saturate network bandwidth better.

Alex Baranau
Sematext :: http://blog.sematext.com/ :: Hadoop - HBase - ElasticSearch -

On Tue, Jul 31, 2012 at 9:09 PM, Mohit Anchlia <mohitanchlia@gmail.com>wrote:

> In the HBase book it mentioned that the default behaviour of write is to
> call sync on each node before sending replica copies to the nodes in the
> pipeline. Is there a reason this was kept default because if data is
> getting written on multiple nodes then likelyhood of losing data is really
> low since another copy is always there on the replica nodes. Is it ok to
> make this sync async and is it advisable?

Alex Baranau
Sematext :: http://blog.sematext.com/ :: Hadoop - HBase - ElasticSearch -

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