WHM / CPANEL Capacity planning and Quality of service

[rzderich]

Hello!

I´m running whm/cpanel hosting platform since last year and i what to share some ideas on quality of service, capacity planning and other problems most of you may have experience, my goal is to find a good way to control quality on the very disperse and wide scenario of web hosting using tools such as cpanel and indutry standard x86 servers:

1-. How to control quality for end user:

We run many web sites, each one have indivual needs, how we can take full profit from each server and at the same time manage quality in order to have happy customers? The average scenario is a mix of low traffic sites and bigger traffic sites. Many need SQL Databases and run scripts, some are hungry resource eating sites due high traffic or poor script coding.

I think the cluster enviroment is the best way to provide resources on demand, but is very dificult to run such a complex enviroment with standart software like cpanel, these concept is more close to a custom development, that most of us just can`t develop due the lact of funds or time and human resources.

I beleave we can manage these with a better model on service plan creation. Considering more than just space, number of accounts and Db`s and traffic to have a more realistic way to assign customers the right service plan.

Building blocks is the model we are following, we start to put machines to serve specific service plans, that mean some machine is running just plan A sites, and other plan B and another one plan C. ( bigger the plan, the machine is designed to manage the better profit with bigger requiremts from customers)

Lets see and example:

Plan 1 easy goin sites with low traffic requirements:

1 P4 3.2GHZ 2GB RAM, 2x150 GB Drives on a serial ATA Raid level 1
average population 400 web sites with 3 to 6 GB of trafic each one, traffic averages under 2 GB.

That config works very well on these scenario, but if you put just one hungry site in the middle of these scenario your machine will be easy overloaded.

A machine with these specs and load can run is you have just easy goin sites, if you discover a change on one site, you can upgrade it to a more powerfull enviroment and manage the load that way, these can maximise profit and at the same time make your customers happy, puting the money and more powerfull hardware on more hungry sites with more expensive service plans.

We have 4 enviroment levels:

(A) 1 CPU P4 3.2GHZ to 3.4GHZ, 2GB average ram, 2 hard drives, 120 to 200 gbytes on raid 1 serving many easy sites. (up to 400, average is 300)

(B) 1 CPU same spects, serving less sites (up to 200) with a more expensive service plan.

(C) 2x XEON 3.2, 2GB, SCSI RAID 1 for huge sites, more expensive, more reliable. (up to 100 sites)
(D) Dedicated Cpanel install for resellers and or multisite companies.

That is my solution right now, that is the way we manage today these issue of quality versus profit.

Im looking for a more scalable platform, looking for opteron powered servers, in order to scale the number of sites per machine with more powerfull hardware. At the time i run 15 machines, and im starting to think in future cos we spend a lot of money on Cpanel.

What you think guys? better to scale vertical with cpanel ( 4 ways opteron big monsters ) or and average config running more machines (horinzontal scale) ?

Anyone whant to share experience in these?

best Regards

Roy A. Zderich
Cyberia Internet.
www.cyberiainternet.com

 

[carock]

We found out the hard way how to reduce the load on a server with two or three high traffic sites compared to the rest hosted on the same box.

We had one site on a dual 2.8G Xeon with 4 Gig RAM that was passing around 400Gig a month. It was a database heavy site too.

MySQL was using 60+% of process resources. Server load averages between 11 and 26, but never below 11.

This site has been steadily increasing traffic over the last year, and we knew something had to be done.

Since MySQL was involved, we decided to try and set up a MySQL cluster. Before we could figure that one out, the site's traffic took a dramatic jump, and we had average 2 second response times for the other 60 sites on that server and server load average over a 24 hour time period of 18 with spikes to 33.

So we had another server of equal configuration loaded up with CentOS, MySql 4.0.25 same as the cPanel server, but NO cPanel installation, no apache and no mail.

We stopped the web site, transferred 2.2 Gig of database over to the new server and fired it all back up.

Now, both the cPanel server hosting the site, and the MySQL server have load averages BELOW 2.0!!! The only site using the new database server is the high traffic one.

So for some reason, the MySQL on the hosting server was either screwed up, or cPanel installation just puts too many things on a single box to allow hosting of more than one site with this kind of traffic.

For load planning and scalability, a central MySQL server may be one of your best resources to keep a high traffic site from hurting the others assuming it will be database driven.

Chuck

 

[webignition]

Chuck,

How does cPanel deal with remove MySQL servers, with respect to the MySQL features available through cPanel?

Will the current cPanel MySQL features still be present, for example can users still continue to add databases etc through cPanel with the databases on a separate server?

 

[rzderich]

Hi,

That´s a good idea. As i know you can attach an independent sql server to whm in order to work with the dedicated mysql server in a way that sould be transparent. I never try it before. Also that can be very good as you can build a robust machine for mysql, i think response times can be a little less fast, as you access databases across the net, but in the other hand that make web servers run without the overhead, you can get solid performance.

In the past I manage several Cobalt servers that way, a big mysql server to serve all our Raq`s, as cobalts have small cpu´s, these make us let sun cobalts survive more time in service. At these time, we have shutdown these product (cobalt bases hosting) cos the OS is outdated and no more supported.

The question is, how dificult is to migrate to these model? (dedicated mysql server and whm/cpanel working just for mail and httpd)

Chuck have you ever attach the mysql server via the metod whm provide?

Best regards
Roy.

 

[carock]

Yes, I set up a test mysql and test cpanel server. I used the Remote MySQL link in WHM on the test server.

It works fine, the only problem I had specifically was the ability to manage both the localhost mysql and the new remote mysql via phpMyAdmin.

For a new server, it doesn't matter and it should work fine. I had a specific task to try and migrate existing users from localhost databases to the new remote database.

This is impractical from the existing user model because the cPanel users no longer have localhost MySQL access through their phpMyAdmin. So the code changes to their web sites would require the system administrator to co-ordinate the copy of MySQL databases to the new server to make sure the latest data is copied.

If you have a new unused server though, the remote MySQL is fine. It's integrated nicely into cPanel as far as I have used it. Only in testing, not production.

Chuck

 

[rzderich]

Hi!

Very good information. I will try these scene for high traffic sites, i`m waiting for a new server soon, then i will try the external dedicated mysql server.

Talking about performance, have you ever try AMD 64 cpus (desktop cpu, looks fine for dedicated servers or for serve low requeriments sites) or just Xeon`s?

I will test and AMD 64 3500 with 2 Gbytes of ram and a sata raid 1. Im looking for a better performer than the P4 3.2 ghz HT or even the 3.4 ghz but cheaper than a Xeon system.

Another task i use to do is "search and destroy" abusive sites, how do you manage to do these? I use to see system health and look for httpd process with more treaths, i research also the bandwidth use. Then i prove the suspects sites at low traffic hours, looking at TOP from a ssh terminal to see how much resourses the site or home page use. Then i take some actions, such as talking with the site owner or webmaster about site script optimization or the option to get a service upgrade.

All the best

Roy A. Zderich
http://www.cyberiainternet.com