Server slowness

[spiros]

I have been getting slow page creation time (for pageviews, start and post new topic) for the last 2-3 weeks on an SSD VPS with 12 GB RAM which was pretty fast without any increase in real traffic (real traffic about 6000 pageviews and 300 posts daily). The host replied with:

Currently there are more than 500 connections to your web server. Many of them are web crawlers and they can cause slowness.

Please check your web server log files for more details about this.

In Apache status I see about 15 connections. Any idea on that?

Using:

root@host [/]# netstat -plane | grep :80 | awk '{print $5}' | grep -Eo '([0-9]{1,3}\.){3}[0-9]{1,3}'| wc -l

I get 588

http://www.translatum.gr/forum/index.php

I have implemented most of the points here:
http://www.simplemachines.org/community/index.php?topic=293441.0

[yaax]

Apache cannot handle so much connections, so it show only few 15-20 in his status page, while most are on waiting status.
I recommend you to replace apache with nginx, then your server will have much better perfomance.
Also you can check from what ip's and clients coming most connections (if this is kind of ddos attack) and block it in firewall and in server config like htaccess or nginx config.

[KnownSyntax]

Depending on what other things you have changed on the server, you'll need to optimize Apache more or possibly move over to another web server service such as ngnix to serve the content with the amount of traffic that you are getting. Adding in more cache based options such as a CDN service, making sure that a majority of things are cached for a week or more, or other tasks to prevent from the connections always requesting pages (minus new content, replying to posts, etc.) can help out a ton too in my experience.