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Chapter 27: Database Mirroring
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Commit (supports up to three replicas in a group). You can also specify if the replica is a
readable secondary. You have three options for this:■ (^) No: The replica will not allow any connections.
■ Yes: The replica will allow all connections for read access, including connections
with older clients.
■ Read-Intent Only: The replica will allow only connections with read-intent
connections.
As you check and uncheck options for your various replicas, you may notice the area below the replicas updates
based on your selections. This summary area provides a quick description of what the various replica modes are, as
well as the readable secondary options.
- Click the Endpoints tab. Here you can confi gure port numbers for your secondary
endpoints. The default port for endpoints is 5022. In addition, you can specify if
you want your endpoint connections encrypted (on by default).
Service Accounts and Endpoints
If your instance runs under a default local system account, you may encounter errors later in this process
when the availability group attempts to create logins on the secondary replicas. It is highly recom-
mended you run SQL Server service under a dedicated Windows service account.- Click the Backup Preferences tab. Here you confi gure where your backups should
occur, as shown in Figure 27-20. You have several options to choose from:
■ (^) Prefer Secondary: Automated backups should occur against secondary repli-
cas. If no secondary replicas are available, backups occur against the primary
replica.
■ (^) Secondary Only: All automated backups must occur against a secondary replica.
■ (^) Primary: All automated backups must occur against a primary replica.
■ (^) Any Replica: Backups can occur on any replica in the availability group.
In addition, you can also set backup priorities for your various replicas. You can
also select to explicitly exclude replicas from being used for backups as well.
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