Upgrading Microsoft Exchange 2003/2007 to Exchange 2010 has many advantages. There are many new features and technologies that customers can take advantage of to help their businesses. The feature our customers are most excited about, and is a huge advantage to them, is the integration of high availability architecture. This major feature is built-in mailbox resiliency without the need for expensive, 3rd party software that’s so complicated no one past the original integration expert can actually support it.
With the Exchange 2010 Database Availability Group (DAG) feature for High Availability, data is replicated on multiple, different servers that are grouped together on the same LAN subnet or across your WAN to another data center. This makes it feasible for a company’s email system to essentially never go down even if the internet in the primary site loses Internet connectivity, or a partial or complete power failure. In the case of failures, other servers that have up to second replicated data stores of the email storage group(s) can execute the receiving and sending of email inside and outside the company. For example, if the internet goes down in one office location, the system automatically points to the other network with replicate email stores, and production continues. This is accomplished best by having the TTL (time to live) set to a relatively short interval (say 1-2 minutes) and the external DNS will redirect the MX record to the secondary site (WAN) or another ISP if there are redundant ISP’s at the primary site. An external DNS hosting facility is best utilized to accomplish this last technical aspect.
“It’s the backend stuff that makes everything work together,” states Marc Hill, President and owner of Stablenet IT Services in Charlotte. “The ability to get and send email is so engrained in our lives, whether we are in the office, or offsite on our smartphones or tablets, that it has become completely mission critical for the majority of companies to have this application available essentially at all times.”
With the new high availability architecture in Exchange 2010, the users never even notice that anything out of the ordinary has happened during a disaster recovery moment.