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From Andrew Purtell <apurt...@apache.org>
Subject Re: Is DFSInputStream.read(long position,...) designed for multi threaded access?
Date Wed, 02 Mar 2011 22:38:27 GMT
I looked at HADOOP-6311 recently when deciding if I wanted to port the full FD-passing bits
of HDFS-347 onto CDH3B3. I see Owen changed his -1 to -0, but that's not really comforting.
How likely is this to go in? Would this go in to CDH if I posted a patch for HADOOP-6311 and
HDFS-347?

My aim here is a fast local read path that respects security, obviously, something that I
won't be supporting myself in production against an increasingly diverging upstream.

    - Andy


--- On Wed, 3/2/11, Todd Lipcon <todd@cloudera.com> wrote:

> From: Todd Lipcon <todd@cloudera.com>
> Subject: Re: Is DFSInputStream.read(long position,...) designed for multi threaded access?
> To: "Jason Rutherglen" <jason.rutherglen@gmail.com>
> Cc: hdfs-user@hadoop.apache.org
> Date: Wednesday, March 2, 2011, 2:10 PM
> On Wed, Mar 2, 2011 at 8:17 AM, Jason
> Rutherglen
> <jason.rutherglen@gmail.com>
> wrote:
> > Todd,
> >
> > Thanks for the reply.  I looked at HDFS-941 which seems to remove the
> > redundant creation of BlockReaders.  That and HDFS-347 will solve some
> > of the issues, however I think there's also the sendmsg() of the file
> > descriptor that also needs to be implemented?
> 
> Yes, see HADOOP-6311. I have an up-to-date patch on this but have not
> yet gotten to posting it since we need 347 to be redone on trunk as
> well.
> 
> -Todd



      

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