Board Optimization - Dynamically Linked Source - Speed Up Your Multiple Site Network & Upgrades

For the purposes of this documentation, "Network" refers to a group of forums on a single server or cluster of servers.

When 3.7.1 PL2 was released, I posted over at vbulletin.com lamenting the fact that I had 15 upgrades to perform and how it would be nice to have a multiple site license to lighten the burden of downloading each install separately. In the end, I spent much more time coming up with this system.

Dynamically Linked Source or DLS allows operators of two or more forums on the same server or cluster, for all intents and purposes, to use one set of source code instead of multiple sets. By using one set of source code, Op code caching is much more efficient as only one copy of the source is cached. This greatly reduces the amount of memory used caching the source code, and also makes it more efficient. It will lead to less fragmentation for systems using APC, XCache, eAccelerator, or other such methods of caching Op code.

The method uses symbolic links to a central repository of the source code. Therefore, upgrades to all sites on the network can be done quickly by just replacing the source. For patch level releases, this means the entire network can be patched with one upload. Upgrades to a new version can be done this way, or a new repository can be created and each site can be upgraded one at a time.

The issue of licensing has also been addressed. Once the product file is installed, and assuming the installation instructions were followed, each installation will report the proper license key when salting cookies, or reporting back to Jelsoft as Vbulletin does from time to time (mostly in the AdminCP).

I contacted the development team at Jelsoft and discussed this method before releasing it, and got the OK from Mike. I was initially concerned that it may break licensing or perhaps give away too much of the license reporting methodology, but now that I look back, it really does not do either.

In tests on a rather large network that contains seven forums with about 7 million posts, hundreds of thousands of registered users, and uses three load balanced servers the load has been reduced by almost 40%. You can see in the graph attached to this thread for the particulars.

I have tried to make the readme as clear as possible, but honestly that was never one of my strong points. I cannot emphasize more that before you implement this method, TEST it first in your sandbox. Also, make sure you backup your software and database before you use this.

I also have included a PDF that explains what is happening in greater detail.

Updates:

8/20/08 - This will work with the latest version of VBSEO (3.2.0 at this time). Add all the files to the DLS except the config file, and run the php-clone.php script.

This product was developed for Andy R from Social Knowledge and released here for others to enjoy.


Please don't forget to click install as I have worked quite a while on this.

[Jafo232]

Originally Posted by hornstar1337

wow you have really gone and done a great job here. i currently have 2 forums running on my server, however as I expand I will really have to go and look into this more.

Even with just 2 forums, by installing this mod, you will cut your memory usage in half (providing your using an opcode cache like APC, Xcache, or eAcc)..

[Jafo232]

I do want to take an opportunity to clarify something I think may be unclear.

When you install this, you define a license key for each site using the DLS system by entering in the license #. This license # that you enter will be used throughout the script for the site it is defined for. This in no way bypasses any licensing methodology in the script. If you enter an invalid license # or a license for a different site than what you defined at vbulletin.com, it will still throw up the red flags for Jelsoft.

The only thing the plugin does is make sure the proper license (as you define it) is returned when called. We contacted the VB team about this and they detailed to us where these areas were so we could build this system without stepping on any licensing issues when it came to their piracy protection schemes.

If you try to use this to have multiple copies of the same license running, it will still be identified exactly the same way it would if they were separate installs.

[y2ksw]

I wonder if this would work on Windows servers ... I suppose not ... (sigh)

[Rebecca217]

This is brilliant. Thank you!

[Jafo232]

Originally Posted by y2ksw

I wonder if this would work on Windows servers ... I suppose not ... (sigh)

Probably not, at least out of the box. I suppose you could use shortcuts instead of symbolic links and then it would work.

[Jafo232]

Originally Posted by djr

*VERY* interesting and I love the out-of-the-box thinking. Truly impressed. Do you know whether this will impact vbSEO? Would it be possible to also include vbSEO in the DLS or isn't that necessary?

We finally got this working with VBSEO... If you upload all the files for vbSEO to the DLS except for the config file, run the php-clone.php script, you should be all set. Really speeds things up!

[KevinL]

This really sounds great!

[Jafo232]

Originally Posted by KevinL

This really sounds great!

Great! Don't forget to mark installed if you find it useful.

[Beermonster]

Where do you put the path to the forum in? there is one line in php-clone.php that says Path to the forum not forums, which path is this?

Edit: and also how are you able to upgrade the databases or is it just files this updates?

[y2ksw]

Originally Posted by Jafo232

Probably not, at least out of the box. I suppose you could use shortcuts instead of symbolic links and then it would work.

I've tried it. Shortcuts won't work. So that's a Linux-only solution