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sys.availability_groups (Transact-SQL) |
Returns a row for each availability group for which the local instance of SQL Server hosts an availability replica. |
rwestMSFT |
randolphwest |
04/18/2024 |
sql |
system-objects |
reference |
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[!INCLUDE SQL Server]
Returns a row for each availability group for which the local instance of SQL Server hosts an availability replica. Each row contains a cached copy of the availability group metadata.
| Column name | Data type | Description |
|---|---|---|
group_id |
uniqueidentifier | Unique identifier (GUID) of the availability group. |
name |
sysname | Name of the availability group. This is a user-specified name that must be unique within the Windows Server Failover Cluster (WSFC). |
resource_id |
nvarchar(40) | Resource ID for the WSFC cluster resource. |
resource_group_id |
nvarchar(40) | Resource Group ID for the WSFC cluster resource group of the availability group. |
failure_condition_level |
int | User-defined failure condition level under which an automatic failover must be triggered, one of the integer values shown in the table immediately below this table. The failure-condition levels (1-5) range from the least restrictive, level 1, to the most restrictive, level 5. A given condition level encompasses all of the less restrictive levels. Thus, the strictest condition level, 5, includes the four less restrictive condition levels (1-4), level 4 includes levels 1-3, and so forth. To change this value, use the FAILURE_CONDITION_LEVEL option of the ALTER AVAILABILITY GROUP (Transact-SQL) statement. |
health_check_timeout |
int | Wait time (in milliseconds) for the sp_server_diagnostics (Transact-SQL) system stored procedure to return server-health information, before the server instance is assumed to be slow or not responding. The default value is 30000 milliseconds (30 seconds). To change this value, use the HEALTH_CHECK_TIMEOUT option of the ALTER AVAILABILITY GROUP (Transact-SQL) statement. |
automated_backup_preference |
tinyint | Preferred location for performing backups on the availability databases in this availability group. The following are the possible values and their descriptions. 0: Primary. Backups should always occur on the primary replica. 1: Secondary only. Performing backups on a secondary replica is preferable. 2: Prefer Secondary. Performing backups on a secondary replica is preferred, but performing backups on the primary replica is acceptable if no secondary replica is available for backup operations. This is the default behavior. 3: Any Replica. No preference about whether backups are performed on the primary replica or on a secondary replica. For more information, see Offload supported backups to secondary replicas of an availability group. |
automated_backup_preference_desc |
nvarchar(60) | Description of automated_backup_preference, one of:PRIMARYSECONDARY_ONLYSECONDARYNONE |
version |
smallint | The version of the availability group metadata stored in the Windows Failover Cluster. This version number is incremented when new features are added. |
basic_features |
bit | Specifies whether this is a Basic availability group. For more information, see Basic Always On availability groups for a single database. |
dtc_support |
bit | Specifies whether DTC support is enabled for this availability group. The DTC_SUPPORT option of CREATE AVAILABILITY GROUP controls this setting. |
db_failover |
bit | Specifies whether the availability group supports failover for database health conditions. The DB_FAILOVER option of CREATE AVAILABILITY GROUP controls this setting. |
is_distributed |
bit | Specifies whether this is a distributed availability group. For more information, see Distributed availability groups. |
cluster_type |
tinyint | 0: Windows Server failover cluster 1: None 2: External cluster (for example, Linux Pacemaker) |
cluster_type_desc |
nvarchar(60) | Text description of cluster type |
required_synchronized_secondaries_to_commit |
int | The number of secondary replicas that must be in a synchronized state for a commit to complete |
sequence_number |
bigint | Identifies the availability group configuration sequence. Incrementally increases every time the availability group primary replica updates the configuration of the group. |
is_contained |
bit | 1: Big data cluster master instance configured for high-availability. 0: all other. |
The following table describes the possible failure condition levels for the failure_condition_level column.
| Value | Failure condition |
|---|---|
1 |
Specifies that an automatic failover should be initiated when any of the following occurs: - The [!INCLUDE ssNoVersion] service is down. - The lease of the availability group for connecting to the WSFC failover cluster expires because no ACK is received from the server instance. For more information, see How It Works: SQL Server Always On Lease Timeout. |
2 |
Specifies that an automatic failover should be initiated when any of the following occurs: - The instance of [!INCLUDE ssNoVersion] doesn't connect to cluster, and the user-specified health_check_timeout threshold of the availability group is exceeded.- The availability replica is in failed state. |
3 |
Specifies that an automatic failover should be initiated on critical [!INCLUDE ssNoVersion] internal errors, such as orphaned spinlocks, serious write-access violations, or too much dumping. This is the default value. |
4 |
Specifies that an automatic failover should be initiated on moderate [!INCLUDE ssNoVersion] internal errors, such as a persistent out-of-memory condition in the [!INCLUDE ssNoVersion] internal resource pool. |
5 |
Specifies that an automatic failover should be initiated on any qualified failure conditions, including: - Exhaustion of SQL Engine worker-threads. - Detection of an unsolvable deadlock. |
Requires VIEW ANY DEFINITION permission on the server instance.