Class AvailabilitySchema.AvailabilityGroupsCluster
- Namespace
- LinqToDB.Tools.DataProvider.SqlServer.Schemas
- Assembly
- linq2db.Tools.dll
sys.availability_groups_cluster (Transact-SQL)
Applies to: √ SQL Server (all supported versions)
Returns a row for each Always On availability group in the Windows Server Failover Clustering (WSFC) . Each row contains the availability group metadata from the WSFC cluster.
[Table(Schema = "sys", Name = "availability_groups_cluster", IsView = true)]
public class AvailabilitySchema.AvailabilityGroupsCluster- Inheritance
-
AvailabilitySchema.AvailabilityGroupsCluster
- Extension Methods
Properties
AutomatedBackupPreference
Preferred location for performing backups on the availability databases in this availability group. One of the following values:
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 preferable, 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 Active Secondaries: Backup on Secondary Replicas (Always On Availability Groups).
[Column("automated_backup_preference")]
[Nullable]
public byte? AutomatedBackupPreference { get; set; }Property Value
- byte?
AutomatedBackupPreferenceDesc
Description of automated_backup_preference, one of:
PRIMARY
SECONDARY_ONLY
SECONDARY
NONE
[Column("automated_backup_preference_desc")]
[Nullable]
public string? AutomatedBackupPreferenceDesc { get; set; }Property Value
FailureConditionLevel
User-defined failure condition level under which an automatic failover must be triggered, one of the following integer values:
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 does not 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.
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 GROUPTransact-SQL statement.
[Column("failure_condition_level")]
[Nullable]
public int? FailureConditionLevel { get; set; }Property Value
- int?
GroupID
Unique identifier (GUID) of the availability group.
[Column("group_id")]
[NotNull]
public Guid GroupID { get; set; }Property Value
HealthCheckTimeout
Wait time (in milliseconds) for the sp_server_diagnostics 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 ALTER AVAILABILITY GROUPTransact-SQL statement.
[Column("health_check_timeout")]
[Nullable]
public int? HealthCheckTimeout { get; set; }Property Value
- int?
Name
Name of the availability group. This is a user-specified name that must be unique within the Windows Server Failover Cluster (WSFC).
[Column("name")]
[Nullable]
public string? Name { get; set; }Property Value
ResourceGroupID
Resource Group ID for the WSFC cluster resource group of the availability group.
[Column("resource_group_id")]
[Nullable]
public string? ResourceGroupID { get; set; }Property Value
ResourceID
Resource ID for the WSFC cluster resource.
[Column("resource_id")]
[Nullable]
public string? ResourceID { get; set; }