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From Michael Segel <michael_se...@hotmail.com>
Subject RE: Client Side buffering vs WAL
Date Wed, 08 Sep 2010 18:12:19 GMT



> From: tsunanet@gmail.com
> Date: Wed, 8 Sep 2010 10:08:52 -0700
> Subject: Re: Client Side buffering vs WAL
> To: user@hbase.apache.org
> 
> On Tue, Sep 7, 2010 at 7:44 AM, Michael Segel <michael_segel@hotmail.com> wrote:
> > So, my question is how long does it take for a record in the WAL to be written to
Disk?
> 
> This happens before the RPC completes successfully.  If the RPC
> succeeds, you know the WAL was written to disk and your data is safe,
> even if there's a server failure.
> 

yes... talked about this last night on IRC. I wanted to confirm that this was the case. 

Buffering put()s on the client side may make sense for most batch applications but when you
need to see it in the database, you want it to go in when you send a put() and not when you
either exceed the buffer or flush the buffer.

I just wanted to make sure that the client connects, writes to HBase WAL and memstore (See
JD, I was paying attention) it will be accessible by others. So the data isn't getting delayed
in another buffer.

Thanks to all for confirming this.

-Mike
 		 	   		  
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