4 server redundant solution

Network setup

Best scenario when all 4 servers are on same LAN (subnet).
Other possible solutions: Server 1 and 2 are on one LAN, Server 3 and 4 are on a different LAN (subnet). A VPN for better security from

server 1 and 2 to server 3 and 4 can be made.

If all 4 servers are on different LANs (subnets) in that case between servers VPNs have to be configured. Drawback - such setup

management becomes too complicated.

If servers are in the different countries (continents), it might cause latency problems which has negative influence on the speed of retrieving/instering data to the DB (loading statistics, trying to retrieve some data, searching for a sound file, etc. will longer than usually).

Workflow

Servers 1 and 2 (S1 and S2) are identical. They serve as gateways with Asterisk + MOR installed.
Both of them have two network interfaces - one for Virtual IP which is visible from outside, and one for local IP for interconnection heartbeat monitoring
LinuxHA heartbeat monitors servers, e.g.
- When S1 fails - S2 sees that and after 10s (default) will take Virtual IP, e.g. will start to serve calls, it is done automatically
- When S1 is back up - S2 returns Virtual IP to S1 and system starts to function in normal work flow (done automatically).

Servers 3 and 4 (S3 and S4) are identical. They serve as MySQL DB.
Both of them have two network interfaces - one for Virtual DB IP (Virtual IP No. 2) which is visible for Asterisk servers S1 and S2, and one for local IP for interconnection heartbeat monitoring
LinuxHA heartbeat monitors servers, e.g.
- When S3 fails - S4 sees that and after 10s (default) will take Virtual IP, it is done automatically
- When S3 is back up - S4 returns Virtual IP to S3 and system starts to function in normal work flow (done automatically).
- S1 connects to S3 over Virtual DB IP
DBs on S3 and S4 are synchronized over MySQL Replication

More info:

Navigation menu