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Hadoop, mail # dev - Need to add fs shim to use QFS


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Re: Need to add fs shim to use QFS
Thilee Subramaniam 2012-10-10, 15:03
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.

Thanks,
- Thilee

 

On 10/10/12 12:05 AM, "Harsh J" <[EMAIL PROTECTED]> 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 <[EMAIL PROTECTED]>
>wrote:
>> On 5 October 2012 18:27, Thilee Subramaniam <[EMAIL PROTECTED]>
>>wrote:
>>
>>> 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
>>>tolerance
>>> through Reed-Solomon encoding as well as replication. There are also a
>>> number of performance and stability improvements, including a rewrite
>>>of
>>> the client library to allow parallel concurrent I/Os. Going forward,
>>>new
>>> 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
>>the
>> 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
>>bridge
>> 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