Daily Archives: July 4, 2019

Implement SQL Server Agent Jobs with AlwaysOn Availability Groups

The function I use fn_hadr_group_is_primary from this post is a UDF (User Defined Function) that we create in the master database. The function gets an Availability Group name as an input parameter and returns a Boolean value indicating weather this instance is a primary replica.

-- fn_hadr_group_is_primary
USE master;
GO
IF OBJECT_ID('dbo.fn_hadr_group_is_primary', 'FN') IS NOT NULL
  DROP FUNCTION dbo.fn_hadr_group_is_primary;
GO
CREATE FUNCTION dbo.fn_hadr_group_is_primary (@AGName sysname)
RETURNS bit
AS
BEGIN;
  DECLARE @PrimaryReplica sysname; 

  SELECT
    @PrimaryReplica = hags.primary_replica
  FROM sys.dm_hadr_availability_group_states hags
  INNER JOIN sys.availability_groups ag ON ag.group_id = hags.group_id
  WHERE ag.name = @AGName;

  IF UPPER(@PrimaryReplica) =  UPPER(@@SERVERNAME)
    RETURN 1; -- primary

    RETURN 0; -- not primary
END; 

Use the fn_hadr_group_is_primary function within a new job step to find if this sql instance is a Primary replica. If this is not a primary replica we issue a stop job request while identifying the current job name using SQL Server Agent Tokens

-- Detect if this instance's role is a Primary Replica.
-- If this instance's role is NOT a Primary Replica stop the job so that it does not go on to the next job step
DECLARE @rc int; 
EXEC @rc = master.dbo.fn_hadr_group_is_primary N'my-ag';

IF @rc = 0
BEGIN;
    DECLARE @name sysname;
    SELECT  @name = (SELECT name FROM msdb.dbo.sysjobs WHERE job_id = CONVERT(uniqueidentifier, '$(ESCAPE_NONE(JOBID))'));
    
    EXEC msdb.dbo.sp_stop_job @job_name = @name;
    PRINT 'Stopped the job since this is not a Primary Replica';
END;