One was presented by Ayla Kol entitled, "High Availability in Microsoft Exchange Server 2007 and Exchange Server 2007 Service Pack 1". She did a good job explaining what's offered in E2K7 RTM for HA and went on to explain what's going to be new in SP1. Here are the highlights for RTM:
- Windows 2003 needs KB921181 to enable File Share Witness (FSW)
- Continuous Cluster Replication (CCR) is limited to 2 nodes
- CCR requires hardware from the Geographically Dispersed Cluster category of the HCL
- FSW should be on hub in primary site
- CCR nodes must be in the same subnet. This poses a problem for geo-clustering
- Best Practice to use a CNAME record for the FSW name. This provides easier failover
- Best Practice to increase tolerance of heartbeat failures to 10
- Log shipping to the passive node is a pull model. The Replication Service monitors logs
- Divergence = loss of mailbox data. This is what happens in a "lossy" recovery. Normally, in CCR the hub's transport dumpster will backfill the recovered node with missing data.
- LLR = lost log resilience. This is what the transport dumpster is for.
- The transport dumpster works only with CCR in RTM. It will work with LCR in SP1
- Recovery from transport dumpster is designed to backfill within 30 seconds
- SP1 will have a GUI for cluster management (finally!)
And now for what we've all been waiting for, Single Copy Replication (SCR)!
- SCR will be included in SP1
- Possible scenarios include: Standalone server to SCR, LCR to SCR, and CCR cluster to SCR
- Designed for datacenters
- CCR can use dissimilar hardware. This offers simplified hardware and storage requirements. Does not require hardware from the Geographically Dispersed Cluster category of the HCL
- No subnet requirements! Can work across different subnets, unlike CCR
- Only works with one database per storage group
- Must be same paths
In a future blog, I hope to write more about CCR and SCR. For now, we're off to the TechEd attendee party at Islands of Adventure. The kids are gonna have a blast!