Exchange Server 2007 introduces a new high-availability feature called Cluster Continuous Replication (CCR).This feature combines the new Exchange Server 2007 log file shipping and replay mechanisms (known as continuous replication) with the features that are available in a more traditional two-node Windows 2003 server active/passive cluster setup.
With CCR, the transaction logs generated on the active node are replicated to the information store on the passive node using log file shipping. These replicated log files are then posted into the database(s) on the passive node using the log file replay technology. This means that should the active node or a database on this node fail or for some other reason go offline, an automatic failover to the passive node will occur.
A Majority Node Set (MNS) quorum with File Share Witness is a completely new type of quorum model that is made available by installing the update (MS KB article 921181) mentioned in this chapter. The update makes it possible to use a file share witness that is external to the cluster as an additional "vote" to determine the status of the cluster in a two-node MNS quorum cluster deployment, which is a requirement to use the CCR functionality in Exchange Server 2007.
The Transport Dumpster is a new feature of the Exchange 2007 Hub Transport server that can submit recently delivered mail after an unscheduled outage. For an e-mail message to be able to be retained in the Transport Dumpster, at least one of the message recipients must have his or her mailbox located on a CCR-based mailbox cluster server, because the Transport Dumpster works only with mailboxes located on a CCR-based mailbox server cluster.
Moving the Exchange resources from node one to node two should be done using the Move-ClusteredMailboxServer CMDlet. In the environment used in this chapter, we did so by issuing the cmdlet Move-ClusteredMailboxServer -Identity:MailboxServer -TargetMachine:EDFS08 -MoveComment:"Verifying the Move Clustered Mailbox Server Functionality!".
When we deployed a cluster with Exchange 2003, the only option available when the stores were going to be backed up was to take a backup of the stores running on the production servers. With CCR (and LCR.), you have the option of taking a backup of the database copies on the passive node, thereby eliminating any heavy load on the active node related to both I/O to the disk spindles as well as CPU usage.
Managing an Exchange 2007 Cluster Continuous Replication (CCR) setup
Part 1: Exchange 2007 Cluster Continuous Replication requirements
Part 2: Setting up Cluster Continuous Replication in Exchange 2007
Part 3: Creating a Windows 2003 cluster for an Exchange 2007 CCR setup
Part 4: Using a file share witness with Exchange 2007 CCR
Part 5: Enable the Transport Dumpster on the Hub Transport server
Part 6: Installing Exchange 2007 on the active node and passive node
Part 7: Testing clustered mailbox server functionality in a CCR setup
Part 8: Exchange 2007 Cluster Continuous Replication (CCR) setup overview
|This chapter excerpt from How to Cheat at Configuring Exchange Server 2007: Including Outlook Web, Mobile, and Voice Access , by Henrik Walther, is printed with permission from Syngress, a division of Elsevier, Copyright 2007.
Click here for the chapter download.
This was first published in March 2008