some questions regarding cluster

[bryan.kewl]

We are planning to build a vicibox cluster, but have some questions
1) For a cluster, its good to have 1 HUGE box for database, and also a decent box for website (thats what I have read) and multiple boxes for asterisk, so it means there will be only 1 web address, but multiple dialing servers, so do we need to manually tell users to which dialing box to connect, or there will a central box controlling other boxes and users will connect to this central server and it will move them to actual server?
1.1) If there is a central server, how do we configure it to act as central, and also how to tell other server that we have a central server (XYZ)?
1.2) If there is a central server, so can it automatically check which asterisk servers are available? For example, we have 1 DB server, 1 Web server, and 5 asterisk servers (and one of them is acting as central server), so if one of the normal asterisk server crashes, are there any chances that the central server itself detect it and stop sending users to the crashed server?
1.3) Do the central server also do the dialing or just act as a controller?
1.4) In case central server crashes, do we need to manually upgrade a normal server to act as central server, or we can automate this process?
1.5) Lets say the DB server crashed, and we bring in another DB server with different IP, now do we need to update each server is cluster manually about the new DB server, or we can just tell the web server and the central server about the new DB server, and it will update others automatically.
1.6) What if the web server crashes, do we again need to update all the servers, or just the DB and central server?

2) after how many agents we will need a new web server?

3) how many users a single DB server can handle? lets say we get a great server with 64GB RAM, SSD RAID1 with 2 disks, and i7-3930K processor, which is among the top 10 processors right nowCpubenchmark.net

4) for the asterisk servers, should we use any decent dual core (or quad core) with 4GB ram, or we can use a more powerful server with 16G(or 32G) RAM, single hard drive (or raid-1) with normal (consumer) hard disks, i7-2600, cpubenchmark.net? I know that the 25 agents limit is more due to some software issues, not hardware, but sometime ago I read somewhere on this forum that someone (i think Op3r, but will check) was able to push upto 80 agents on a single dialer using cluster, so even if I can get upto 50 agents but pushing good hardware, means we will need to manage a lot less servers.

[williamconley]

1) The Vicibox install .iso has a q/a method to ask you about the use of the machine presently being installed. It will alter the system to allow it to fit the purpose (ie: if this machine is a "dialer only" vs "db and web" etc). The Vicibox PDF is somewhat helpful in description of these options during install.

2) My personal favorite manual for clustering is rather old, but still gives a fair description of clustering for those who want to use it (we created this manual a couple years ago).

http://www.poundteam.com/downloads/Vicidial Multi-Server Manual by Poundteam - Latest.pdf