Datasheet

16 CHAPTER 1 INTRODUCING EXCHANGE SERVER 2010
XYZZY requires a high-availability solution that not only provides email access in the event
of an Exchange server failure in the local office, but also provides a contingency in case their
headquarters office has to be shut down. Email should be hosted in the Colorado office in the
event the Florida office has to be closed. The solution that switches active email services over
to Colorado must be smooth and simple.
The company decided to implement Exchange Server 2010 database availability groups
(DAGs). The Eastern US DAG has three Mailbox servers: two Mailbox servers are in South
Florida and one in Colorado. The databases assigned to the two South Florida servers will first
fail-over to one or the other of those servers. In the event that both servers in Florida must be
shut down, the databases will be switched over to the Mailbox server in Colorado.
MAPI and Directory on the Middle Tier
Previously, in all versions of Outlook and Exchange Server, the Outlook client (using MAPI
over RPC, not RPC over HTTP) had to be configured to connect to a specific Exchange server.
A traditional MAPI client-to-Exchange configuration is shown in Figure 1.7. First, the Outlook
MAPI client would connect to a process the Exchange server’s System Attendant service runs
to get a referral to a global catalog server (for the Global Address List) or possibly to handle
directory lookups on behalf of the Outlook client.
Figure 1.6
Simple database
availability group
Database Availability Group
Executives
(active copy)
Marketing
(active copy)
Accounting
(active copy)
Marketing
(passive copy)
Accounting
(passive copy)
Executives
(passive copy)
Executives
(passive copy)
Honolulu
Mailbox
server
Denver
Mailbox
server
Tokyo
Mailbox
server