server load on linux

[PWillard]

hello there,
we are running vbulletin v4.1.5 on a centos v5.6 server running on mysql v5.5.16 and php v5.2.10.
server hardware has 8GB ram with Intel Core Quad CPU Q8200 @ 2.33GHz
we are running 5 different sites on this dedicated server and only 1 site its running vbulletin..
all use mysql databases for different things, but usually the server load is about 4 or 5 right now its a bit high

[(05:24 PM)][(root@alpha)] [(~)] $ uptime
17:25:42 up 12 days, 3:30, 1 user, load average: 9.64, 7.94, 7.01

I would like to know whats causing this.
if we put the vbulletin site on pause then the server load drops to about 0.52 and 0.70 stable..
the mysql database tables are on InnoDB file format. the traffic of the site is about 3k uniques a day!

addons currently enabled on the site are
VSa - Sub-Forum Manager v3.1.2
VSa - Advanced Permissions Based on Post Count v5.1
VSa - Advanced Forum Statistics v7.0.3
VSa - Advanced Forum Rules v5.0.5
vBSEO :: Sitemap Generator v3.0
vBSEO v3.6.0
Usergroup Color Bar v2.0.0
Report by Threads with Templates v1.0
Quick trash Posts v1.2
Anti Double Post System v2.2
KeyCAPTCHA v3.6.0
Sphinx Search v1.2.2

[Andreas]

I don't know most of thos Add-ons but purely judging from the names

VSa - Advanced Forum Statistics v7.0.3

would be my No. 1 candidate for further investigation.

3K unique visitors doesn't seem that much - analyze your server configuration and log files, especially MySQL slow queries.

[PWillard]

admins are the only ones allowed to see Advanced Forum Statistics v7.0.3

[Andreas]

That doesn't mean much, there could still be (heavy) queries getting executed for everyone.

[Max Taxable]

the traffic of the site is about 3k uniques a day!That's not as relevant as what those 3000 uniques are doing. How many of them are repeatedly loading pages or large files, as in a DoS attack? How many are just pure spam, scrapers, etc? Bad actors.

CloudFlare - get it. You'll end all of these issues and more.

[charlesr]

My site was crawling (and falling over completely every few days) from search on InnoDB (that vB4 sneakily switched to when I upgraded from vB3). I changed to a VPS with fast I/O which helped and then changed all the tables back to MyISAM and since then load rarely goes over 1

The innodb index size was 1.5GB
With myisam it dropped massively.

[PWillard]

how can I check the current innodb index size ?