On 02/18/2013 12:26 PM, Brendon Colby wrote: > Rasmus said: > > "Just because you see an open() syscall doesn't mean the cache isn't > used. The open() is there because PHP by default does open+fstat for > performance reasons. If you look carefully you will see there is just > an open() and no read() calls. So it opens the file, uses the stat > struct from the open fd to get the inode and fetches the op_array from > the opcode cache. This can be made more efficient, but this report is > incorrect in assuming the cache isn't being used." > > This is exactly what I'm seeing when I strace an httpd process - > mostly open() and fstat() calls w/o any read() calls. This makes sense > to me, however, the problem with this is as far as I understand it, > that an open() on an NFS file system causes an automatic gettattr() > call to the server. Doing this completely bypasses the NFS attribute > cache, which is why we're seeing so many getattr requests to our NFS > server despite having an attribute cache timeout of 60 seconds. For > those familiar with NFS, we could just as well disable our attribute > cache at this point, which is almost never recommended because of > performance reasons.
Wow, people are still serving web files over NFS? Sounds painful. But, this is what APC's apc.include_once_override setting tries to address. Try turning that on. -Rasmus -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
