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From Thilee Subramaniam <thi...@quantcast.com>
Subject Re: Need to add fs shim to use QFS
Date Wed, 10 Oct 2012 15:03:29 GMT
Hi Steve,

Like Harsh said, HADOOP-8886 addresses removing KFS from apache tree.

But I interpret your suggestion as 'moving qfs.jar out of apache tree, and
keeping the jar in possibly a maven repo externally. The new fs shim for
QFS will pull this jar from the repo upon compilation etc.'.
Please correct me if I am wrong.

- Thilee


On 10/10/12 12:05 AM, "Harsh J" <harsh@cloudera.com> wrote:

>Hi Steve,
>Check out https://issues.apache.org/jira/browse/HADOOP-8886 for the
>KFS removal. Seems relevant to your question here.
>On Wed, Oct 10, 2012 at 12:52 AM, Steve Loughran <stevel@hortonworks.com>
>> On 5 October 2012 18:27, Thilee Subramaniam <thilee@quantcast.com>
>>> We at Quantcast have released QFS 1.0 (Quantcast File System) to open
>>> source. This is based on the KFS 0.5 (Kosmos Distributed File System),
>>> a C++ distributed filesystem implementation. KFS plugs into Apache
>>> Hadoop via the 'kfs' shim that is part of Hadoop codebase.
>>> QFS has added support for permissions, and also, provides fault
>>> through Reed-Solomon encoding as well as replication. There are also a
>>> number of performance and stability improvements, including a rewrite
>>> the client library to allow parallel concurrent I/Os. Going forward,
>>> releases of KFS will come from QFS.
>> Does this mean the kfs plugin can go from the apache tree?
>> One problem that we've always had with KFS is that nobody ever tested
>> filesystem, and it was inevitably out of sync with what was in KFS.
>> Have you considered just pulling the kfs lib out and releasing the
>> classes yourself? It's what the other FS suppliers do, as it gives them
>> more control over the libraries, including the ability to release more
>> often.
>> -steve
>Harsh J

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