Moodle in English: Poor performance and connection timeouts (Media Temple)

Poor performance and connection timeouts (Media Temple)

by T Strait - Monday, July 12, 2010, 9:23 PM

I have just set up a Moodle system on Media Temple's dedicated-virtual server and from the onset performance was terrible. The server itself has the following specs:

Dual-core Xeon @ 2.33Ghz
894Mb RAM
CentOS
Apache 2.2.3
PHP5.2

However, even before performance tweaking I would have 3 out of 5 connection attempts timeout. After setting up the APC php accelerator, connection timeouts are down to 1 out of 5. But performance remains inconsistently abysmal. I have attached a shot from Firebug showing a course main page load (only one assignment, 2 users) taking 21 seconds, with some simple GIF requests failing.

My only tweaks outside of the norm are upping the settings for file transfers in php.ini to:

upload_max_filesize = 300 M
post_max_size = 300 M
memory_limit = 200 M

httpd.conf setting of note:

<IfModule prefork.c>
StartServers 1
MinSpareServers 1
MaxSpareServers 3
ServerLimit 50
MaxClients 50
MaxRequestsPerChild 4000
</IfModule>

LimitRequestBody 0

To test for yourself, my server info is:
www.sachsresearch.net
user: testuser
pw: Testuser1!

Should I be considering a new host or is there something I have overlooked? Thanks in advance!

Re: Poor performance and connection timeouts (Media Temple)

by corprew reed - Tuesday, July 13, 2010, 12:19 AM

<IfModule prefork.c>
StartServers 1
MinSpareServers 1
MaxSpareServers 3
ServerLimit 50
MaxClients 50
MaxRequestsPerChild 4000
</IfModule>

try setting this to

<IfModule prefork.c>
StartServers 2
MinSpareServers 2
MaxSpareServers 5
ServerLimit 50
MaxClients 50
MaxRequestsPerChild 1000
</IfModule>

and see if it makes a difference. there may be an issue you're running into with not having enough servers to fulfill the requests.

----

Also, are you running php through FastCGI?

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Re: Poor performance and connection timeouts (Media Temple)

by T Strait - Tuesday, July 13, 2010, 1:57 AM

Hi - thanks for your reply.

I made your adjustments but I don't think Apache is the problem - it doesn't get the request to serve consistently (I think).

I am not running through FastCGI. Apache CPU % maxes at ~40% when i hit the site. However, Apache just doesn't get the request or doesn't respond to it.

This issue is EXTREMELY COMMON when sending POST commands. (I assume these are POSTs - adding users to groups, adding assignments via dropdowns). I would say these actions time out ~75% of the time. Clicking links on the pages (GETs, I assume) have a much higher success rate.

Is there perhaps some kind of DNS/connectivity issue? My domain is sachsresearch.com, but once logging in for some reason the URL resorts back to the server IP. Firebug indicates inconsistently long "DNS lookup" "connecting" and "waiting" issues. If nothing happens quickly it doesn't happen. I have to reload/reclick to try and get the server to respond. Could this be involved?

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Re: Poor performance and connection timeouts (Media Temple)

by George Dickens - Tuesday, July 13, 2010, 2:58 AM

I've got an "Invalid current value: 16777216" in the default course size. I've increased the size of maximum upload to 100 Mb in the php.ini file. I've manually changed the maxbytes in the site database and in each course. I've restarted the server (both the apache program and the actual physical machine). I've turned on debugging, set to developer. However, when I go through the new course set up process, I get to the point where I've uploaded my files and set up my scorm. When I click the button to "Save and return to course" I get directed to the modedit.php page which comes up blank (I don't even get a debugging window). I then have to log back into the frontpage, as if I've been completely logged out. Any help to resolve this issue would be greatly appreciated. OBTW, I'm uploading a 76 Mb file (well within the new maximum upload size) and videos within my course presentation and I'm using moodle 1.9.7. Thanks!

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Hardware and performance

Poor performance and connection timeouts (Media Temple)