High-load and high-availability questions.

[Sabayon]

Hi. I am looking for some board-system, which can live in HA cluster.

So, what it can be.
1) load balancer (ipvs, nginx, does not matter).
2) 2+ front-end servers (PHP code working there)
3) MySQL cluster - master + replica-set. Probably, ipvs for replica-set can be used, but it will only generate a lot of unneccesary traffic inside network.
4) all of this separated between 2xDC with round-trip 20-30ms between them.

So, questions about VB.
1) where is sessions keeps? If it is on disk, or in memcached/DB.
2) which files keeps at local disks? I have to sync them between front-ends, and it is very bad, if there are a lot of this files.
3) what about licensing while we have many front-end servers? ofc, we're have only one domain for all this construction. but...
4) does BB know something about master/slave? Can i set master-Mysql server and replicas separate at config?
5) read-only mode, if master is unavailable? Not ugly messages like "aaa, i can't complete mysql query!"?

Also what about php-fpm (yeah, all of CMS should work with it, but in fact - not)?
Do you have ready nginx rewrite configuration?

[Zachery]

1. vBulletin stores sessions in the database.
2. Files? Which files are we talking about? PHP fileS? They go into the webserver. You'll need to be more specific about which files you're asking about.
3. Our license is per active installation (more or less), multiple web/db servers don't play into it for a single installation.
4. We have basic master slave configuration in the software.
5. There isn't a read only mode function in the software.
Some of our customers use php-fpm without issue.
We do not support or have a working nginx rewrite configuration for vBulletin 4 at this time.

[Sabayon]

I mean, what files generated by VB, saves do disk? Avatars, attaches, what else?

[Zachery]

By default, nothing.

If you want:
attachments
avatars
user profile pictures
css

[Riasat]

I run vb just fine on php-fpm/nginx. Also, I believe their is an unofficial vb4 nginx rewrite rules is posted somewhere in this forum.