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From Jason Rutherglen <jason.rutherg...@gmail.com>
Subject Re: Is DFSInputStream.read(long position,...) designed for multi threaded access?
Date Wed, 02 Mar 2011 16:17:57 GMT
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?

Jason

On Tue, Mar 1, 2011 at 5:58 PM, Todd Lipcon <todd@cloudera.com> wrote:
> Hi Jason,
>
> Yes, this method is currently very inefficient.. HDFS-941 will
> hopefully improve this situation, but currently there's no
> particularly efficient way to do multithreaded random access.
>
> -Todd
>
> On Tue, Mar 1, 2011 at 4:24 PM, Jason Rutherglen
> <jason.rutherglen@gmail.com> wrote:
>> It's unsynchronized however it's creating a new BlockReader on each
>> call, that seems like a problem?
>>
>
>
>
> --
> Todd Lipcon
> Software Engineer, Cloudera
>

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