Using RM without a Virtual IP

[simon]

Yes, I know we are supposed to use VirtualIP/NLB for HA RM with Sheep Server, but hear me out:

1. we can create two treatment DNs under Sheep Server, with contact pointing to RM1 and RM2
2. we can set RM1 and RM2 to be in Warm Standby
3. enable addp to ensure that RM1/RM2 and Sheep Server are aware of each other

YET....Why in the world Sheep Server keeps on trying to use RM2 even though it is down? If I look through the logs, I will see Sheep server keep on trying to route every second treatment request to RM2, wait for 30 seconds and only then route it to RM1. Every time. Why Sheep server does not detect that RM2 is down and just use RM1?!!!

I tried everything, and it would not work. But it should... Especially when RM1/RM2 are in Warm Standby! Sheep server should not be sending requests to RM2 when it is in backup.

[Kubig]

When you are using RM cluster with VIP, all SIP components which communicate with RM, must communicate with RM via VIP address only. So, if the RM goes down and the standby goes up to the primary (active role), the ex-active has to set VIP down and ex-standby RM must set VIP up on the host. So, from this point of view is clearly understandable that other components does not need to know what RM is currently active, only one of that must have VIP address up. Are you using active-standby with IP address takeover or bonding? I strongly recommend to use bonding (I know that the reason is strange), but from real-experience it is truly better. Another mode is active-active where the SIP server acts as load-balancer, in this deployment you need not VIP address.

[bublepaw]

I would follow recommendations from Kubig and configure active-active RM (there is detailed description how to do it in dep. guide). In such case SIP Server automatically pings each RM using  SIP message and load balances traffic amongst available RM's. If one goes down and doesn't respond to oos-check pings SIPS stops using this one and sends all traffic to remaining one. Two DN's pointing to different RM is not supported although for some cases it might work.