php-general Digest 17 Aug 2010 08:08:44 -0000 Issue 6897
Topics (messages 307490 through 307491):
Re: Including files on NFS mount slow with APC enabled
307490 by: Mark Hunting
307491 by: Mark Hunting
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--- Begin Message ---
Thanks for your answer. I have tested this option before, and it indeed
disables the stat() operation. However, it doesn't disable the open()
operation, which is about 10x slower than the stat() call (see my
example trace).
On 08/16/2010 07:21 PM, Jonathan Tapicer wrote:
> Hi,
>
> APC checks by default if every included file was modified doing a stat
> call. You can disable it, setting apc.stat to 0
> (http://www.php.net/manual/en/apc.configuration.php#ini.apc.stat). Try
> if that improves the performance. Of course, you should manually
> delete the APC opcode cache every time you modify a PHP file, since
> APC won't detect that it was modified.
>
> Regards,
>
> Jonathan
>
> On Mon, Aug 16, 2010 at 10:21 AM, Mark Hunting <[email protected]> wrote:
>
>> I am struggling with the performance of some websites that use a lot of
>> includes (using include_once). The files are on a NFS mount (NFSv4), and
>> I use APC to speed things up. APC has enough memory, and I see all
>> included files are in the APC cache. apc.include_once_override is
>> enabled. This is on a Ubuntu Linux 10.04 server.
>>
>> What surprises me is that using strace I see apache open()ing all
>> included files. I would think this is not necessary as APC has these
>> files in its cache. Opening a file takes 1-3 ms, the websites include
>> 100-200 files, so this costs about half a second for each request. I
>> tried a lot to prevent this but my options are exhausted. Is it normal
>> that all these files are open()ed each time, and if so how can I speed
>> up these includes?
>>
>> Part of the trace is below, look especially at the first line where 2ms
>> are lost while this file is in the APC cache:
>>
>> open("/[removed]/library/Zend/Application.php", O_RDONLY) = 1440 <0.002035>
>> fstat(1440, {st_mode=S_IFREG|0755, st_size=11365, ...}) = 0 <0.000137>
>> fstat(1440, {st_mode=S_IFREG|0755, st_size=11365, ...}) = 0 <0.000124>
>> fstat(1440, {st_mode=S_IFREG|0755, st_size=11365, ...}) = 0 <0.000133>
>> mmap(NULL, 11365, PROT_READ, MAP_SHARED, 1440, 0) = 0x7faf3f068000
>> <0.000395>
>> stat("/[removed]/library/Zend/Application.php", {st_mode=S_IFREG|0755,
>> st_size=11365, ...}) = 0 <0.000219>
>> munmap(0x7faf3f068000, 11365) = 0 <0.000151>
>> close(1440) = 0 <0.000845>
>>
>> Thanks,
>> Mark
>>
>> --
>> PHP General Mailing List (http://www.php.net/)
>> To unsubscribe, visit: http://www.php.net/unsub.php
>>
>>
>>
>
--- End Message ---
--- Begin Message ---
I now notice that when I replace include_once with include the open()
call disappears. That's very nice, but why does include_once need to
open the file, even when apc.include_once_override is enabled? Is this a
bug?
On 08/16/2010 03:21 PM, Mark Hunting wrote:
> I am struggling with the performance of some websites that use a lot of
> includes (using include_once). The files are on a NFS mount (NFSv4), and
> I use APC to speed things up. APC has enough memory, and I see all
> included files are in the APC cache. apc.include_once_override is
> enabled. This is on a Ubuntu Linux 10.04 server.
>
> What surprises me is that using strace I see apache open()ing all
> included files. I would think this is not necessary as APC has these
> files in its cache. Opening a file takes 1-3 ms, the websites include
> 100-200 files, so this costs about half a second for each request. I
> tried a lot to prevent this but my options are exhausted. Is it normal
> that all these files are open()ed each time, and if so how can I speed
> up these includes?
>
> Part of the trace is below, look especially at the first line where 2ms
> are lost while this file is in the APC cache:
>
> open("/[removed]/library/Zend/Application.php", O_RDONLY) = 1440 <0.002035>
> fstat(1440, {st_mode=S_IFREG|0755, st_size=11365, ...}) = 0 <0.000137>
> fstat(1440, {st_mode=S_IFREG|0755, st_size=11365, ...}) = 0 <0.000124>
> fstat(1440, {st_mode=S_IFREG|0755, st_size=11365, ...}) = 0 <0.000133>
> mmap(NULL, 11365, PROT_READ, MAP_SHARED, 1440, 0) = 0x7faf3f068000
> <0.000395>
> stat("/[removed]/library/Zend/Application.php", {st_mode=S_IFREG|0755,
> st_size=11365, ...}) = 0 <0.000219>
> munmap(0x7faf3f068000, 11365) = 0 <0.000151>
> close(1440) = 0 <0.000845>
>
> Thanks,
> Mark
>
>
--- End Message ---
