This is the fifth and final post in a series about the various options to achieve HA and DR with Exchange 2010. In the first, I broke the DAG into its basic components (Active Manager and DAG replication). In the second, I gave a quick overview of Native DAG. In the third, I covered a hybrid approach that combined DAG replication and Active Manager for local HA, and array/SAN based replication for remote site recovery. In the fourth, I described an option that deploys Exchange in a standalone configuration and leverages a hypervisor to achieve local high availability.
This one will cover Exchange’s Third Party Replication. This one definitely has a lot of cool factor in it. It actually leverages DAG (in the form of Active Manager) with array or SAN-based replication technology. You get all the automatic failover, live patching, Exchange-aware coolness of DAG, zero data loss, and you only have to deploy one copy of the data at each site.
Although synchronous operation is possible with both Options 2 and 3, this is the only option shown that combines synchronous replication with automatic failover.
This option will use a plugin from EMC to coordinate the replication engine with Active Manager. This would be either Replication Enabler for Exchange 2010 (free!), or AutoStart 5.3 with the Exchange 2010 module. This option can also use a virtualization platform like Hyper-V or VMware, but a hypervisor is not necessary to leverage the benefits of this option.
Here are the cost factors:
- Storage: 2
- Network: 2
Architects and managers will typically consider this option when:
- Lossless, automatic failover is required
- Minimal hardware footprint is desired
- There is minimal latency between the sites
- A hardware VSS protection scheme is available for rapid recovery in the event of database corruption
- Live patching is required