RE: [users@httpd] IO load due to apache? Normal httpd behavior or script related?
So I did the change, restarted apache and... Fixed! So changing to shm did fixed the issue with APC for PHP. Greetings Date: Wed, 16 May 2012 16:26:42 +0100 From: tevans...@googlemail.com To: users@httpd.apache.org Subject: Re: [users@httpd] IO load due to apache? Normal httpd behavior or script related? On Wed, May 16, 2012 at 2:57 PM, G VM drums_...@hotmail.com wrote: Likely a script problem, httpd wont cause harm Did some further investigation and it seems APC (php opcode cache) generates this IO(or so it seems). http://serverfault.com/questions/361032/high-disk-i-o-when-cache-is-used that is pretty ancient RHEL. Not that ancient. ahhh so this is a VM Yes :p any further point on this? If you are not sure what APC is then you cant need it and should disable it Although I might not have a full understanding of what it does the customer is using it (passively). So disabling is not an option. Sometimes disabling stuff from which you don't know what it does backfires ;) One of these days I will be able to change the setting and verify that this fixed my problem. Thanks for your response anyway:) Grtz APC stand for Alternative PHP Cache. It aims to speed up your Apache webserver by caching the parsed PHP object code, in a manner I don't understand because I use neither PHP nor APC. However, there are two takeaways from those two sentences. The first is that it is a cache, the site should function without it. The second is that it is meant to speed up your webserver. If it is not doing so, and is instead causing load issues, it seems counter productive to use it. Cheers Tom - To unsubscribe, e-mail: users-unsubscr...@httpd.apache.org For additional commands, e-mail: users-h...@httpd.apache.org
RE: [users@httpd] IO load due to apache? Normal httpd behavior or script related?
Likely a script problem, httpd wont cause harm Did some further investigation and it seems APC (php opcode cache) generates this IO(or so it seems). http://serverfault.com/questions/361032/high-disk-i-o-when-cache-is-used that is pretty ancient RHEL. Not that ancient. ahhh so this is a VM Yes :p any further point on this? If you are not sure what APC is then you cant need it and should disable it Although I might not have a full understanding of what it does the customer is using it (passively). So disabling is not an option. Sometimes disabling stuff from which you don't know what it does backfires ;) One of these days I will be able to change the setting and verify that this fixed my problem. Thanks for your response anyway:) Grtz From: noel.but...@ausics.net To: users@httpd.apache.org Date: Wed, 16 May 2012 10:12:47 +1000 Subject: Re: [users@httpd] IO load due to apache? Normal httpd behavior or script related? On Mon, 2012-05-14 at 17:41 +0200, G VM wrote: Hi all, Recently I found out one server generating alot of load on our storage. Likely a script problem, httpd wont cause harm Linux 2.6.18-274.7.1.el5 that is pretty ancient httpd 25431apache DEL REG 253,3 13 /tmp/apc.Fm8SAS httpd 25454apache DEL REG 253,3 13 /tmp/apc.Fm8SAS httpd 25622apache DEL REG 253,3 13 /tmp/apc.Fm8SAS httpd 25792apache DEL REG 253,3 13 /tmp/apc.Fm8SAS httpd 25794apache DEL REG 253,3 13 /tmp/apc.Fm8SAS httpd 25846apache DEL REG 253,3 13 /tmp/apc.Fm8SAS httpd 25849apache DEL REG 253,3 13 /tmp/apc.Fm8SAS ... The only other is for sshd and another for vmware tools. ahhh so this is a VM If I try to do ls -lh /tmp/apc.Fm8SAS I get no such file or directory. Using the access time I would see if this file is accessed over and over again. Am I missing something here? Is this apache doing a fstat() call for example? Or is this file created and deleted over and over again at a very fast pace that I can't access it (this seems less likely to me). Has anyone seen such behaviour in httpd? Or does someone knows a little more of the inner workings of httpd? The name does me think that APC (sort of php module iirc) is having something to do with this: apc.ini:apc.mmap_file_mask=/tmp/apc.XX The config file seems to confirm this. If you are not sure what APC is then you cant need it and should disable it
Re: [users@httpd] IO load due to apache? Normal httpd behavior or script related?
On Wed, May 16, 2012 at 2:57 PM, G VM drums_...@hotmail.com wrote: Likely a script problem, httpd wont cause harm Did some further investigation and it seems APC (php opcode cache) generates this IO(or so it seems). http://serverfault.com/questions/361032/high-disk-i-o-when-cache-is-used that is pretty ancient RHEL. Not that ancient. ahhh so this is a VM Yes :p any further point on this? If you are not sure what APC is then you cant need it and should disable it Although I might not have a full understanding of what it does the customer is using it (passively). So disabling is not an option. Sometimes disabling stuff from which you don't know what it does backfires ;) One of these days I will be able to change the setting and verify that this fixed my problem. Thanks for your response anyway:) Grtz APC stand for Alternative PHP Cache. It aims to speed up your Apache webserver by caching the parsed PHP object code, in a manner I don't understand because I use neither PHP nor APC. However, there are two takeaways from those two sentences. The first is that it is a cache, the site should function without it. The second is that it is meant to speed up your webserver. If it is not doing so, and is instead causing load issues, it seems counter productive to use it. Cheers Tom - To unsubscribe, e-mail: users-unsubscr...@httpd.apache.org For additional commands, e-mail: users-h...@httpd.apache.org
RE: [users@httpd] IO load due to apache? Normal httpd behavior or script related?
Hi Tom, You absolutely have a point there. The site functions without it, however APC improves the sites performance(it should as there is almost 100% cache hit, however I didn't and can't do decent investigation into that). Note that the customer configures all application parts(php, apache, mysql, ...). So if the customer writes bad code and the site doesn't perform, that is not a problem. However load on the VM is kind of ok. It is the IO load to the san that I want to get down :) Grtz APC stand for Alternative PHP Cache. It aims to speed up your Apache webserver by caching the parsed PHP object code, in a manner I don't understand because I use neither PHP nor APC. However, there are two takeaways from those two sentences. The first is that it is a cache, the site should function without it. The second is that it is meant to speed up your webserver. If it is not doing so, and is instead causing load issues, it seems counter productive to use it. Cheers Tom - To unsubscribe, e-mail: users-unsubscr...@httpd.apache.org For additional commands, e-mail: users-h...@httpd.apache.org
Re: [users@httpd] IO load due to apache? Normal httpd behavior or script related?
On Mon, 2012-05-14 at 17:41 +0200, G VM wrote: Hi all, Recently I found out one server generating alot of load on our storage. Likely a script problem, httpd wont cause harm Linux 2.6.18-274.7.1.el5 that is pretty ancient httpd 25431apache DEL REG 253,3 13 /tmp/apc.Fm8SAS httpd 25454apache DEL REG 253,3 13 /tmp/apc.Fm8SAS httpd 25622apache DEL REG 253,3 13 /tmp/apc.Fm8SAS httpd 25792apache DEL REG 253,3 13 /tmp/apc.Fm8SAS httpd 25794apache DEL REG 253,3 13 /tmp/apc.Fm8SAS httpd 25846apache DEL REG 253,3 13 /tmp/apc.Fm8SAS httpd 25849apache DEL REG 253,3 13 /tmp/apc.Fm8SAS ... The only other is for sshd and another for vmware tools. ahhh so this is a VM If I try to do ls -lh /tmp/apc.Fm8SAS I get no such file or directory. Using the access time I would see if this file is accessed over and over again. Am I missing something here? Is this apache doing a fstat() call for example? Or is this file created and deleted over and over again at a very fast pace that I can't access it (this seems less likely to me). Has anyone seen such behaviour in httpd? Or does someone knows a little more of the inner workings of httpd? The name does me think that APC (sort of php module iirc) is having something to do with this: apc.ini:apc.mmap_file_mask=/tmp/apc.XX The config file seems to confirm this. If you are not sure what APC is then you cant need it and should disable it signature.asc Description: This is a digitally signed message part
