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Re: file_handle_cache branch ready for review

From: Julian Foad <julianfoad_at_btopenworld.com>
Date: Mon, 9 Jan 2012 08:55:59 +0000 (GMT)

Stefan Fuhrmann wrote:

> Ivan Zhakov wrote:
>>   In your branch your introduce handles to handles.
>> APR does the same. Is that unreasonable?
>> 4. It seems current implementation reuses file handles even error is
>> occurred when working with the handle. It's potentially dangerous from
>> my point view.
>>
> Interesting point. But I think it will not cause issues in
> our case because we use it only within a FSFS "session".
> Any I/O error should result in a failure of the respective FS
> operation, in turn freeing the whole cache instance.
>
> The whole problem with I/O improvement is that there
> is probably no other way to make progress in the next
> 3 years: Some of it could be addressed within APR,
> but that won't be available for Apache < 2.4 (2.6?).
> A better solution is FSv2 but that is at least 3 years
> away from now.

It is worth considering putting this kind of work into the APR source code.  We have close links with APR: some of the APR developers are Subversion developers.  Historically, what we have done before when developing an improvement that is best suited to being in APR, is:

  * write the new code in Subversion first;
  * port the new code to APR;
  * make Subversion use the APR version if it is available, otherwise the Subversion version of the code;
  * test Subversion using both versions of the code;
  * submit a patch to the APR project;
  * wait a few years;
  * strip out Subversion's own copy of the code.

- Julian
Received on 2012-01-09 09:57:11 CET

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