sys.availability_groups (Transact-SQL)
Applies to:
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:PRIMARY SECONDARY_ONLY SECONDARY NONE |
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. |
Failure condition level values
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 SQL Server 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 SQL Server 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 SQL Server 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 SQL Server internal errors, such as a persistent out-of-memory condition in the SQL Server 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. |
Permissions
Requires VIEW ANY DEFINITION
permission on the server instance.
Related content
Feedback
https://aka.ms/ContentUserFeedback.
În curând: Pe parcursul anului 2024, vom elimina treptat Probleme legate de GitHub ca mecanism de feedback pentru conținut și îl vom înlocui cu un nou sistem de feedback. Pentru mai multe informații, consultați:Trimiteți și vizualizați feedback pentru