I have a VPS level 3 plan with Hostgator, providing a server memory of 768MB. I only run one website on it. It's an affiliate wordpress blog and I have optimized its speed as much as I can - mostly by using the W3 total cache plugin. Its still not loading as fast as I would like to be however, sometimes having first render times of up to 4 or 6 seconds, and sometimes under a second. (Overall load time is usually up to 10 seconds or so) So I checked my resource alert logs in the power panel - and It looks like every day I have a few yellow and red alerts. Here's an example list:

Nov 30, 2010 10:15:39 AM Green zone slmmemorylimit
Nov 30, 2010 10:10:39 AM Yellow zone slmmemorylimit
Nov 30, 2010 10:09:39 AM Red zone slmmemorylimit
Nov 30, 2010 06:16:39 AM Green zone slmmemorylimit
Nov 30, 2010 06:14:39 AM Red zone slmmemorylimit
Nov 30, 2010 02:33:39 AM Green zone slmmemorylimit
Nov 30, 2010 02:28:39 AM Red zone slmmemorylimit
Nov 30, 2010 01:30:39 AM Green zone slmmemorylimit
Nov 30, 2010 01:29:39 AM Yellow zone slmmemorylimit
Nov 30, 2010 01:26:39 AM Green zone slmmemorylimit
Nov 30, 2010 01:25:39 AM Yellow zone slmmemorylimit
Nov 29, 2010 12:29:39 PM Green zone slmmemorylimit
Nov 29, 2010 12:24:40 PM Yellow zone slmmemorylimit
Nov 29, 2010 12:23:39 PM Red zone slmmemorylimit
Nov 29, 2010 12:22:39 PM Yellow zone slmmemorylimit
Nov 29, 2010 10:27:39 AM Green zone slmmemorylimit
Nov 29, 2010 10:23:39 AM Yellow zone slmmemorylimit
Nov 29, 2010 10:22:39 AM Green zone slmmemorylimit
Nov 29, 2010 10:20:39 AM Red zone slmmemorylimit
Nov 29, 2010 10:19:40 AM Yellow zone slmmemorylimit

Is this normal for my type of traffic, do I need to be concerned yet? According to awstats my traffic for those two days was:

Day------Visits---Pages---Hits---Bandwidth
28 Nov---2144---5719---74380---1.10 GB
29 Nov---2844---8061---98895---1.49 GB

and according to the traffic log in power panel my traffic usage for those two days were:

Nov 28 601.00 MB Incoming 1,699.34 MB Outgoing
Nov 29 492.12 MB Incoming 1,323.03 MB Outgoing

First of all, I take it that its normal that the bandwidth amount shown in the awstats is different than the overall MB amount shown in the traffic log?


Now - how can I find it out what exactly is causing the resource alerts? E.g. what script or applications? Or which visitors? Maybe there some undesirable referrers that drain unnecessary resources. (In my htaccess, I have hotlink prevention set as well as a couple of referrers already blocked)

Is it possible that some of this comes from too much receiving mail? I do have several email addresses set up and get a fair amount of stuff plus a lot of failed delivery notices on an address that is being spoofed (SPF is set). If I delete some of my email addresses (most of them I dont really use anyway), would that help? Or is it that if people/websites continued to sent email to them that it would still drain resources on my server?

I read on some webpage that modifying the Apache Memory Usage Limit can be a solution. But since Im the only user on my VPS, with usage set to unlimited I dont think this can help me in any way?

Is it possible to do some setting that will tell the kernel what processes to kill first in case of a red alert, before going random?

Last but not least, what is TOP command and can it help me here?

Obviously Im asking all these questions in the hope of tweaking/reducing my server memory as I dont think I can afford an upgrade to level 4 which would be 30 dollars more (with 1,1GB memory).

Thanks so much for any insight and help,
Dennis

Install nginx as reverse proxy, serve all static files via nginx instead of apache. nginx usually uses very small amounts of ram compared to apache.

The term slmmemorylimit usually used in virtuozzo containers or openvz. virtuozzo usually won't allow usage of swap so you are left with your ram only.

Originally Posted by SysAssist

Install nginx as reverse proxy, serve all static files via nginx instead of apache. nginx usually uses very small amounts of ram compared to apache.

The term slmmemorylimit usually used in virtuozzo containers or openvz. virtuozzo usually won't allow usage of swap so you are left with your ram only.

OpenVZ doesn't have slm memory management, only virtuozzo does.

You might want to optimize the vps to serve the content more efficiently. If you can tell us what's exactly on the website I might be able to make recommendations.