Availability replica properties (General Page) for Always On availability groups
Applies to: 
SQL Server
Use this dialog box to viewthe properties of an availability replica.
Task List
To view availability replica properties
UI element list
Availability group name
Name of the availability group. This is a user-specified name that must be unique within the Windows Server Failover Cluster (WSFC).
Server instance
Server name of the instance of SQL Server that is hosting this replica and, for a non-default instance, its instance name.
Role
Primary
Currently the primary replica.
Secondary
Currently a secondary replica.
Resolving
Currently the replica role is in the process of being resolved to either the primary or secondary role.
Availability mode
The availability mode of the replica, one of:
Asynchronous commit
The primary replica can commit transactions without waiting for the secondary to write the log to disk.
Synchronous commit
The primary replica waits to commit a given transaction until the secondary replica has written the transaction to disk.
For more information, see Availability Modes (Always On Availability Groups).
Failover mode
The failover mode of the replica, one of:
Automatic
Automatic failover. The replica is a target for automatic failovers. This is supported only if the availability mode is set to synchronous commit.
Manual
Manual failover. The replica can only be failed over to manually by the database administrator.
Connections in primary role
The type of client connections supported when the replica owns the primary role.
Allow all connections
All connections are allowed to the databases in the primary replica. This is the default setting.
Allow read/write connections
Connections where the Application Intent connection property is set to ReadOnly are disallowed. When the Application Intent property is set to ReadWrite or the application intent connection property is not set, the connection is allowed.
Readable Secondary
Whether an availability replica that is performing the secondary role (that is, a secondary replica) can accept connections from clients, one of:
No
No direct connections are allowed to secondary databases of this replica. They are not available for read access. This is the default setting.
Read-intent only
Only direct read-only connections are allowed to secondary databases of this replica. The secondary database(s) are all available for read access.
Yes
All connections are allowed to secondary databases of this replica, but only for read access. The secondary database(s) are all available for read access.
For more information, see Active Secondaries: Readable Secondary Replicas (Always On Availability Groups).
Session timeout (seconds)
The time-out period, in seconds. The time-out period is the maximum time that the replica waits to receive a message from another replica before considering connection between the primary and secondary replica have failed. Session timeout detects whether secondaries are connected the primary replica. On detecting a failed connection with a secondary replica, the primary replica considers the secondary replica to be NOT_SYNCHRONIZED. On detecting a failed connection with the primary replica, a secondary replica simply attempts to reconnect.
Note
Session timeouts do not cause automatic failovers.
Endpoint URL
String representation of the user-specified database mirroring endpoint that is used by connections between primary and secondary replicas for data synchronization. For information about the syntax of endpoint URLs, see Specify the Endpoint URL When Adding or Modifying an Availability Replica (SQL Server).