4 ms·
I'd be surprised if it made a difference, but the definition of a dead or comatose server would seem to include failover cluster members.
by SloopJon 11y ago
I'd be surprised if it made a difference, but the definition of a dead or comatose server would seem to include failover cluster members.
- jpollock 11y agoMost organisations I've worked for were scaled N+1 for day-to-day reliability with 2N for disaster recovery. This meant that the total servers required were 2(N+1). You get even more idle servers when you consider that they were scaled for New Year's eve traffic, which is typically 10x regular peak traffic (phone system). 30% idle is easily achievable if you're doing proper disaster recovery (recovery when the entire office is gone due to earthquake, flood, fire, etc).
- stephengillie 11y agoThis is where crazy VM engineering can come into play. Something like a "Triple-passive" 3-VM server - it hosts 3 VMs, each is the passive node of a 2-node SQL Cluster. You start with 4 identical servers, running bare metal on 3 and a hypervisor on the 4th. In normal operation, the 3 bare metal servers do all of the work. But when one goes down, the role moves to the VM, where it might run in degraded mode until the physical server is restored.