New Webmin/Virtualmin install running slow (comparing two webmin installs)

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#1 Wed, 11/06/2013 - 19:37
vachikg

New Webmin/Virtualmin install running slow (comparing two webmin installs)

Hello All,

I have two nodes with slicehost.

Node 1: running ubuntu 10.04 with webmin 3.84

Node 2: running ubuntu 12.04 with webmin 4.03

Node 2 is running way slower than node 1.

I am trying to figure out why but I can't. Both have 1024mb ram.

I ran a PHP bencmark script and the results were fairly similar. http://www.php-benchmark-script.com/

7.50sec(node1) vs 7.85sec (node2). So it seems PHP code runs about the same time.

My problem is with Wordpress sites. When I run the exact identical Wordpress site with same DB, on node 1 it runs multiple times faster. Loads in 1-2 seconds while on node 2 it takes 3-5 seconds.

Can someone tell me what might be the problem?

Wed, 11/06/2013 - 22:24
andreychek

Howdy,

Well, Webmin/Virtualmin isn't involved during the actual process of serving websites -- Apache answers the web requests, and then hands it off to PHP.

You're likely seeing some sort of setup difference on the systems, or maybe even some sort of software difference.

You may want to verify what processes are running on both systems -- if system two has more processes running, or the processes are larger, there may be less RAM available.

You may also want to review the PHP Execution Mode that's being used -- you can review that in Server Configuration -> Website Options.

Could server one be configured to some sort of caching, such as memcache? That can make a pretty significant different in performance too.

-Eric

Thu, 11/07/2013 - 13:38
vachikg

both are set to: Apache mod_php (run as Apache's user)

What else can I check for that is drastically giving a performance difference?

Thu, 11/07/2013 - 13:46
andreychek

Howdy,

Did you have any thoughts on the other possibilities I mentioned above, such as what apps are running on both servers, and whether the one server is using any kind of caching?

As far as the apps go, what is the output of these two commands on both systems:

free -m
uptime

That will show what sort of load both systems are seeing, as well as how much RAM is available.

-Eric

Thu, 11/07/2013 - 14:07
vachikg

please check this out:

http://screencast.com/t/2NqIehe1kzDw

I don't know if they are running any caching. I think it's a pure base install..how can I check?

Thu, 11/07/2013 - 14:25
vachikg

top one is the slow one

Thu, 11/07/2013 - 14:29
andreychek

Okay, the load average information (uptime) looks about the same for both.

However, the first server you mentioned, the one that's slow -- that one is using much more swap space.

That likely means that more services are running on it, or that the services that are running are consuming more RAM.

Whenever swap space is being used, that's a sign that things may start to slow down a bit, and may be the cause of what you're seeing.

That's difficult to say, unfortunately, as there's many plausible causes for what you're seeing.

However, if it were my server -- the first place I'd start is to figure out what services I don't need running on the new server, and to shut them down in order to free up RAM.

And I would keep working at that, until my server showed that little to no swap space that was being used.

-Eric

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