How to implement auto disable functionality of SQL Agent Jobs

Purpose of the Article

This article is devised to give a way of auto disabling the SQL Server Agent jobs in case of failures. In some cases, it is required to disable the job if failed otherwise SQL Server Agent will keep trigger the job and job will keep processing the data, it may lead to huge data discrepancy and other issues like unnecessary failures notifications to the users etc.

How we can implement auto disable functionality of jobs in case of failures

1.      Get list of all the jobs having status as failed using msdb.sysjobs and msdb.jobhistory tables.

2.      Update the Enabled flag of the failed jobs to 0 in msdb.sysjobs table

3.      There should a job  e.g ‘Auto_Disable_Failed_Jobs’ which should run the T-SQL script for above 2 steps. Frequency of the job can be every 1 or 2 mins.        

Steps to auto disable the Jobs in case of failures

1.      Below is the script which gives the list of failed jobs as well as update statement to disable the failed jobs:

USE MSDB

GO

--Declare Table Variable

DECLARE @FailedJobs TABLE

(NAME VARCHAR(500),

[MESSAGE] VARCHAR(2000),

LASTRUNDATE VARCHAR(500),

LASTRUNTIME VARCHAR(500))

-- Getting Failed Jobs

INSERT INTO @FailedJobs

(NAME,[MESSAGE],LASTRUNDATE,LASTRUNTIME)

SELECT 

    J.[NAME] AS [NAME],  

    H.MESSAGE AS [MESSAGE],  

    H.RUN_DATE AS LASTRUNDATE,   

    H.RUN_TIME AS LASTRUNTIME

FROM SYSJOBHISTORY H  

    INNER JOIN SYSJOBS J

              ON H.JOB_ID = J.JOB_ID  

  WHERE J.ENABLED = 1   

        AND H.INSTANCE_ID IN 

        (SELECT MAX(H.INSTANCE_ID)  

            FROM SYSJOBHISTORY H GROUP BY (H.JOB_ID))  

        AND H.RUN_STATUS = 0  

                            

  --Disabling the Failed Jobs

  UPDATE SJ

  SET [enabled] = 0

  FROM sysjobs SJ

       INNER JOIN @FailedJobs F

              ON SJ.NAME = F.NAME

             

2.      Create a SQL Agent Job e.g Auto_Disable_Failed_Jobs and run the above code in the job step:

3.      If we don’t want to check the failure status for all the jobs available in an instance of SQL Server then we can filter the job name within the script.

4.      Once Job issue is resolved, System admin or DB admin / support team can enable the job manually.

Conclusion

By using the above mentioned steps, we can implement the auto disable functionality of failed jobs.

SQL Server AGENT

I have collected some general facts related to SQL Server Agent and how you configure it. Hope it will help you.

SQL Server Agent is the service SQL Server uses to perform administrative tasks called jobs. Jobs are made up of one or more steps to accomplish the administrative task you need performed. Jobs can be executed on a recurring schedule and they have multiple methods to notify and record the results of the job.

Configuring SQL Server Agent

The SQL Server Agent service is installed once for each named instance of SQL Server installed on the server. For the default instance the service is called SQLSERVERAGENT. Named instances are called SQLAgent$instancename.

Service Accounts

SQL Server Agent runs as a service on the SQL Server and that service needs a user account to run under. The Agent service can run under a built-in account such as Network Service or System. It can also run under a local user account or domain account.

It is a best practice to use a low privileged domain account for the SQL Server Agent service to ensure it has access to only those resources it needs. This will also allow the Agent to connect to remote servers and access network resources you've granted permission to. Additionally, if your SQL Server is running in a cluster the SQL Server Agent service account MUST use a domain account, it cannot use a built-in or local account.

You'll be prompted to configure the SQL Agent user account during SQL Server installation. If you need to change the configuration after installation you can do this via SQL Server Configuration Manager.

Books Online has a complete description of the all issues you should consider before choosing an account for SQL Server Agent. The primary note about these considerations is all the built-in accounts have security vulnerabilities.

This is of particular importance because if your users are allowed to create their own jobs (executed under the SQL Agent account) your users may access secure resources via SQL Agent they would not normally have available to them. This is critically important to consider for your organization's data security particularly if you must comply with various regulations such asPCI, HIPAA, etc.

General Configuration Options

There are a few SQL Agent settings you can customize to meet your needs, some of the most common are listed below. Unless otherwise noted, these options can be configured via SSMS or using the msdb.dbo. sp_set_sqlagent_properties

system stored procedure.

Auto-Restart Services

The SQL Server and SQL Server Agent services monitor each other and restart each other if the other service fails. You can enable or disable the auto restart of either service. Note that these options should be disabled on clusters.

SQL Agent Log Files

After installation the SQL Agent log files will be configured to use the path %SQL Install Path%\MSSQL\LOG. If the log file location doesn't meet your needs you'll find the path is not configurable during installation and is not something you can modify in the GUI.

You can get instructions for moving the log file and a T-SQL script to reconfigure your log file path in my earlier post, Moving Default Directories in SQL Server. You will need to restart SQL Agent service for these changes to take effect.

You can also configure limits to the size of Agent log data and storage duration of Agent logs. You can limit the rows stored in the log both by total number of history rows and total number of rows per job. You can also restrict how much Agent history is kept by time period (e.g. last 30 days…)

Execution of SQL Agent Job using Seed File

Purpose of the Article

This article is devised to give a way of running the jobs on demand irrespective of scheduled process. This is very useful in such a case when there is no fixed time for data processing. Incoming data can come anytime and at the same time, system should run the job for data processing. To achieve this, many times we schedule our jobs to run at every half an hour/ 10 mins/ 15 mins etc which in turn wastage of system resources. We can control unnecessary execution of job by using Seed file that tells to Job whether it has to start execution or not.

What is Seed File?

Seed file can be any type of blank file (.txt,csv,.xls) that can be used as input parameter to start the execution of any process. For quintessence-

IF Seed file is available

BEGIN

            START THE PROCESS

END

ELSE IF Seed file is not available

BEGIN

BYPASS THE PROCESS

END

How to control the execution of jobs using Seed file?

1.      To control the execution of jobs, we need an additional step that should be the first step of the job which should check whether seed file is available in the source folder or not.

2.      If seed file is available then job should go to next step and execute as expected and at last step, Job should delete the seed file.

3.      If seed file is not available in the source folder then Job should by pass the steps and should quit with reporting success.

Steps to control the execution of Jobs using seed file:

1.  Create first step of the job for checking whether file is exists or not. For checking file existence and Deletion, we are using XP_FILEEXIST and XP_CMDSHELL extended stored procedures. Below is the code which checks whether file is exists or not.

If file exists, we are simply doing select 1

If file does not exists then we are raising the error with message- ‘Seed file is not available’

DECLARE @Flag INT

DECLARE @FilePath VARCHAR(500)

DECLARE @DelFilePath NVARCHAR(500)

SELECT @FilePath = '\\IND-SQL-01\Processing\Start_Processing.txt'

EXEC MASTER..XP_FILEEXIST @FilePath, @Flag OUT

IF @Flag = 1

BEGIN

       SELECT 1

END

ELSE

BEGIN

   RAISERROR('Seed File is not available',16,1)

END

GO

Fig showing the first step of the job for checking file existence

2.      Create one more step that should be the last step of the job that should delete the seed file if exists to clean the source folder for next execution. Below is the code for deleting the file:

DECLARE @Flag INT

DECLARE @FilePath VARCHAR(500)

DECLARE @DelFilePath NVARCHAR(500)

SELECT @FilePath = '\\IND-SQL-01\Processing\Start_Processing.txt'

SELECT @DelFilePath = 'DEL' + SPACE(1) + @FilePath

EXEC MASTER..XP_FILEEXIST @FilePath, @Flag OUT

IF @Flag = 1

BEGIN

   EXEC MASTER..XP_CMDSHELL @DelFilePath

END

                 Fig showing the last step of the Job for cleaning the seed file

3.      Go to Step first then Edit then Advance. Set the below setting

a.      On Success : Go to Next Step

b.      On Failure:  Go to Last Step.

4.      Job Steps:

In this way, we can bypass the processing steps if seed file is not available and we can save unnecessary utilization of system resources required for execution of the job.

Conclusion

By using the above mentioned steps, we can implement on demand job execution functionality.

Job step wise duration counts

select step_id [Step No],step_name [Step Name],case when LastRunDuration is null then NULL else STUFF(CONVERT(CHAR(8), DATEADD(SECOND, ABS(LastRunDuration), '19000101'), 8), 1, 2, CAST(LastRunDuration / 3600 AS VARCHAR(12))) end LastRunDuration
   FROM (select step_id,step_name, CASE
          WHEN run_duration > 0
          THEN
               (run_duration / 1000000) * (3600 * 24)
             + (run_duration / 10000 % 100) * 3600
             + (run_duration / 100 % 100) * 60
             + (run_duration % 100)
          ELSE
             NULL
       END AS LastRunDuration from msdb.dbo.sysjobhistory where job_id='A09DCA56-E235-4A87-A3D7-C3BB9D823F20' and run_status=1 and step_id <> 0
   and run_date >= (select MAX(run_date) from msdb.dbo.sysjobhistory where step_name='CHECK_job_to_complete')
   ) T

Job Schedule and Execution Details

IF EXISTS (SELECT *
           FROM    tempdb.dbo.sysobjects
           WHERE   id = OBJECT_ID(N'[tempdb].[dbo].[JobHistoryInformation]')
                )
        DROP TABLE [tempdb].[dbo].[JobHistoryInformation]
GO
CREATE TABLE [tempdb].[dbo].[JobHistoryInformation]
(
        job_id uniqueidentifier NOT NULL,
         last_run_date nvarchar (20) NOT NULL,
         last_run_time nvarchar (20) NOT NULL,
         next_run_date nvarchar (20) NOT NULL,
         next_run_time nvarchar (20) NOT NULL,
         next_run_schedule_id INT NOT NULL,
         requested_to_run INT NOT NULL,
         request_source INT NOT NULL,
         request_source_id sysname
                   COLLATE database_default NULL,
         running INT NOT NULL,
         current_step INT NOT NULL,
         current_retry_attempt INT NOT NULL,
         job_state INT NOT NULL
 )
   
DECLARE @job_owner   sysname
DECLARE @is_sysadmin   INT
SET @is_sysadmin   = isnull (is_srvrolemember ('sysadmin'), 0)
SET @job_owner   = suser_sname ()
       
INSERT INTO [tempdb].[dbo].[JobHistoryInformation]
   EXECUTE master.dbo.xp_sqlagent_enum_jobs @is_sysadmin, @job_owner

SELECT job_name,StartTime ScheduledStartTime,EndTime ScheduledEndTime,next_scheduled_run_date,
LastRunOutcome,case when LastRunDuration is null then NULL else STUFF(CONVERT(CHAR(8), DATEADD(SECOND, ABS(LastRunDuration), '19000101'), 8), 1, 2, CAST(LastRunDuration / 3600 AS VARCHAR(12))) end LastRunDuration,
schedule_name,[Description],Freq_Type,Freq_Interval
FROM
(
SELECT SJ.name as job_name
, SJ.enabled as is_job_enabled
, SS.enabled as is_schedule_enabled
/*, ISNULL(SJ.description, '') as job_desc*/
, SS.name as schedule_name
, CASE freq_type
WHEN 1 THEN 'Occurs on ' + STUFF(RIGHT(active_start_date, 4), 3,0, '/') + '/' + LEFT(active_start_date, 4) + ' at '
+ REPLACE( RIGHT(CONVERT(varchar(30),
CAST(convert(varchar(8), STUFF(STUFF(RIGHT('000000' + CAST(active_start_time as varchar(10)), 6), 3, 0, ':' ), 6, 0, ':' ), 8) as datetime) /* hh:mm:ss 24H */
, 9), 14), ':000', ' ') /* HH:mm:ss:000AM/PM then replace the :000 with space.*/
WHEN 4 THEN 'Occurs every ' + CAST(freq_interval as varchar(10))
+ ' day(s) '
+ CASE freq_subday_type
WHEN 1 THEN 'at '+ LTRIM(REPLACE( RIGHT(CONVERT(varchar(30), CAST(convert(varchar(8), STUFF(STUFF(RIGHT('000000' + CAST(active_start_time as varchar(10)), 6), 3, 0, ':' ), 6, 0, ':' ), 8) as datetime), 9), 14), ':000', ' '))
WHEN 2 THEN 'every ' + CAST(freq_subday_interval as varchar(10)) + ' second(s)'
WHEN 4 THEN 'every ' + CAST(freq_subday_interval as varchar(10)) + ' minute(s)'
WHEN 8 THEN 'every ' + CAST(freq_subday_interval as varchar(10)) + ' hour(s)'
ELSE '' END
+ CASE WHEN freq_subday_type in (2,4,8) /* repeat seconds/mins/hours */
THEN ' between '+ LTRIM(REPLACE( RIGHT(CONVERT(varchar(30), CAST(convert(varchar(8), STUFF(STUFF(RIGHT('000000' + CAST(active_start_time as varchar(10)), 6), 3, 0, ':' ), 6, 0, ':' ), 8) as datetime), 9), 14), ':000', ' '))
+ ' and '
+ LTRIM(REPLACE( RIGHT(CONVERT(varchar(30), CAST(convert(varchar(8), STUFF(STUFF(RIGHT('000000' + CAST(active_end_time as varchar(10)), 6), 3, 0, ':' ), 6, 0, ':' ), 8) as datetime), 9), 14), ':000', ' '))
ELSE ''
END
WHEN 8 THEN
'Occurs every ' + CAST(freq_recurrence_factor as varchar(10))
+ ' week(s) on '
+
REPLACE( CASE WHEN freq_interval&1 = 1 THEN 'Sunday, ' ELSE '' END
+ CASE WHEN freq_interval&2 = 2 THEN 'Monday, ' ELSE '' END
+ CASE WHEN freq_interval&4 = 4 THEN 'Tuesday, ' ELSE '' END
+ CASE WHEN freq_interval&8 = 8 THEN 'Wednesday, ' ELSE '' END
+ CASE WHEN freq_interval&16 = 16 THEN 'Thursday, ' ELSE '' END
+ CASE WHEN freq_interval&32 = 32 THEN 'Friday, ' ELSE '' END
+ CASE WHEN freq_interval&64 = 64 THEN 'Saturday, ' ELSE '' END
+ '|', ', |', ' ') /* get rid of trailing comma */
+ CASE freq_subday_type
WHEN 1 THEN 'at '+ LTRIM(REPLACE( RIGHT(CONVERT(varchar(30), CAST(convert(varchar(8), STUFF(STUFF(RIGHT('000000' + CAST(active_start_time as varchar(10)), 6), 3, 0, ':' ), 6, 0, ':' ), 8) as datetime), 9), 14), ':000', ' '))
WHEN 2 THEN 'every ' + CAST(freq_subday_interval as varchar(10)) + ' second(s)'
WHEN 4 THEN 'every ' + CAST(freq_subday_interval as varchar(10)) + ' minute(s)'
WHEN 8 THEN 'every ' + CAST(freq_subday_interval as varchar(10)) + ' hour(s)'
ELSE '' END
+ CASE WHEN freq_subday_type in (2,4,8) /* repeat seconds/mins/hours */
THEN ' between '+ LTRIM(REPLACE( RIGHT(CONVERT(varchar(30), CAST(convert(varchar(8), STUFF(STUFF(RIGHT('000000' + CAST(active_start_time as varchar(10)), 6), 3, 0, ':' ), 6, 0, ':' ), 8) as datetime), 9), 14), ':000', ' '))
+ ' and '
+ LTRIM(REPLACE( RIGHT(CONVERT(varchar(30), CAST(convert(varchar(8), STUFF(STUFF(RIGHT('000000' + CAST(active_end_time as varchar(10)), 6), 3, 0, ':' ), 6, 0, ':' ), 8) as datetime), 9), 14), ':000', ' '))
ELSE ''
END
WHEN 16 THEN
'Occurs every ' + CAST(freq_recurrence_factor as varchar(10))
+ ' month(s) on '
+ 'day ' + CAST(freq_interval as varchar(10)) + ' of that month '
+ CASE freq_subday_type
WHEN 1 THEN 'at '+ LTRIM(REPLACE( RIGHT(CONVERT(varchar(30), CAST(convert(varchar(8), STUFF(STUFF(RIGHT('000000' + CAST(active_start_time as varchar(10)), 6), 3, 0, ':' ), 6, 0, ':' ), 8) as datetime), 9), 14), ':000', ' '))
WHEN 2 THEN 'every ' + CAST(freq_subday_interval as varchar(10)) + ' second(s)'
WHEN 4 THEN 'every ' + CAST(freq_subday_interval as varchar(10)) + ' minute(s)'
WHEN 8 THEN 'every ' + CAST(freq_subday_interval as varchar(10)) + ' hour(s)'
ELSE '' END
+ CASE WHEN freq_subday_type in (2,4,8) /* repeat seconds/mins/hours */
THEN ' between '+ LTRIM(REPLACE( RIGHT(CONVERT(varchar(30), CAST(convert(varchar(8), STUFF(STUFF(RIGHT('000000' + CAST(active_start_time as varchar(10)), 6), 3, 0, ':' ), 6, 0, ':' ), 8) as datetime), 9), 14), ':000', ' '))
+ ' and '
+ LTRIM(REPLACE( RIGHT(CONVERT(varchar(30), CAST(convert(varchar(8), STUFF(STUFF(RIGHT('000000' + CAST(active_end_time as varchar(10)), 6), 3, 0, ':' ), 6, 0, ':' ), 8) as datetime), 9), 14), ':000', ' '))
ELSE ''
END
WHEN 32 THEN
'Occurs ' +
CASE freq_relative_interval
WHEN 1 THEN 'every first '
WHEN 2 THEN 'every second '
WHEN 4 THEN 'every third '
WHEN 8 THEN 'every fourth '
WHEN 16 THEN 'on the last '
END
+ CASE freq_interval WHEN 1 THEN 'Sunday'
WHEN 2 THEN 'Monday'
WHEN 3 THEN 'Tuesday'
WHEN 4 THEN 'Wednesday'
WHEN 5 THEN 'Thursday'
WHEN 6 THEN 'Friday'
WHEN 7 THEN 'Saturday'
WHEN 8 THEN 'day'
WHEN 9 THEN 'weekday'
WHEN 10 THEN 'weekend'
END
+ ' of every ' + CAST(freq_recurrence_factor as varchar(10)) + ' month(s) '
+ CASE freq_subday_type
WHEN 1 THEN 'at '+ LTRIM(REPLACE( RIGHT(CONVERT(varchar(30), CAST(convert(varchar(8), STUFF(STUFF(RIGHT('000000' + CAST(active_start_time as varchar(10)), 6), 3, 0, ':' ), 6, 0, ':' ), 8) as datetime), 9), 14), ':000', ' '))
WHEN 2 THEN 'every ' + CAST(freq_subday_interval as varchar(10)) + ' second(s)'
WHEN 4 THEN 'every ' + CAST(freq_subday_interval as varchar(10)) + ' minute(s)'
WHEN 8 THEN 'every ' + CAST(freq_subday_interval as varchar(10)) + ' hour(s)'
ELSE '' END
+ CASE WHEN freq_subday_type in (2,4,8) /* repeat seconds/mins/hours */
THEN ' between '+ LTRIM(REPLACE( RIGHT(CONVERT(varchar(30), CAST(convert(varchar(8), STUFF(STUFF(RIGHT('000000' + CAST(active_start_time as varchar(10)), 6), 3, 0, ':' ), 6, 0, ':' ), 8) as datetime), 9), 14), ':000', ' '))
+ ' and '
+ LTRIM(REPLACE( RIGHT(CONVERT(varchar(30), CAST(convert(varchar(8), STUFF(STUFF(RIGHT('000000' + CAST(active_end_time as varchar(10)), 6), 3, 0, ':' ), 6, 0, ':' ), 8) as datetime), 9), 14), ':000', ' '))
ELSE ''
END
WHEN 64 THEN 'Runs when the SQL Server Agent service starts'
WHEN 128 THEN 'Runs when the computer is idle'
END as [Description]
, CASE freq_type
WHEN 1 THEN 'One Time'
WHEN 4 THEN CASE freq_subday_type WHEN 1 THEN 'Daily'
WHEN 2 THEN 'Second-ly'
WHEN 4 THEN 'Minutely'
WHEN 8 THEN 'Hourly'
ELSE ''
END
WHEN 8 THEN 'Weekly'
WHEN 16 THEN 'Monthly'
WHEN 32 THEN 'Monthly, relative to freq_interval'
WHEN 64 THEN 'Runs when the SQL Server Agent service starts'
WHEN 128 THEN 'Runs when the computer is idle'
END As [Freq_Type]
, CASE freq_subday_type
WHEN 1 THEN 'At the specified time'
WHEN 2 THEN 'Every ' + CAST(freq_subday_interval as varchar(10)) + ' Second(s)'
WHEN 4 THEN 'Every ' + CAST(freq_subday_interval as varchar(10)) + ' Minute(s)'
WHEN 8 THEN 'Every ' + CAST(freq_subday_interval as varchar(10)) + ' Hour(s)'
ELSE ''
END AS freq_subday_type
, CASE
WHEN freq_type = 4 /* (daily) */ THEN 'Every ' + CAST(freq_interval as varchar(10)) + ' Day(s)'
WHEN freq_type = 8 /* (weekly) */ THEN
REPLACE( CASE WHEN freq_interval&1 = 1 THEN 'Sunday, ' ELSE '' END
+ CASE WHEN freq_interval&2 = 2 THEN 'Monday, ' ELSE '' END
+ CASE WHEN freq_interval&4 = 4 THEN 'Tuesday, ' ELSE '' END
+ CASE WHEN freq_interval&8 = 8 THEN 'Wednesday, ' ELSE '' END
+ CASE WHEN freq_interval&16 = 16 THEN 'Thursday, ' ELSE '' END
+ CASE WHEN freq_interval&32 = 32 THEN 'Friday, ' ELSE '' END
+ CASE WHEN freq_interval&64 = 64 THEN 'Saturday, ' ELSE '' END
+ '|', ', |', ' ') /* get rid of trailing comma */
WHEN freq_type = 16 THEN 'On Day ' + CAST(freq_interval as varchar(10)) + ' of Every Month'
WHEN freq_type = 32 /* (monthly) */ THEN 'Every ' +
CASE freq_interval WHEN 1 THEN 'Sunday'
WHEN 2 THEN 'Monday'
WHEN 3 THEN 'Tuesday'
WHEN 4 THEN 'Wednesday'
WHEN 5 THEN 'Thursday'
WHEN 6 THEN 'Friday'
WHEN 7 THEN 'Saturday'
WHEN 8 THEN 'Day'
WHEN 9 THEN 'Weekday'
WHEN 10 THEN 'Weekend day'
END
ELSE ''
END as [freq_interval]
, CASE WHEN freq_type = 8 /* (weekly) */ THEN 'Every ' + CAST(freq_recurrence_factor as varchar(10)) + ' Week(s)'
WHEN freq_type = 16 /* (monthly) */ THEN 'Every ' + CAST(freq_recurrence_factor as varchar(10)) + ' Month(s)'
WHEN freq_type = 32 /* (monthly relative) */ THEN 'Every ' + CAST(freq_recurrence_factor as varchar(10)) + ' Week(s)'
ELSE ''
END as freq_recurrence_factor
, LTRIM(REPLACE( RIGHT(CONVERT(varchar(30), CAST(convert(varchar(8), STUFF(STUFF(RIGHT('000000' + CAST(active_start_time as varchar(10)), 6), 3, 0, ':' ), 6, 0, ':' ), 8) as datetime), 9), 14), ':000', ' ')) as starttime
, LTRIM(REPLACE( RIGHT(CONVERT(varchar(30), CAST(convert(varchar(8), STUFF(STUFF(RIGHT('000000' + CAST(active_end_time as varchar(10)), 6), 3, 0, ':' ), 6, 0, ':' ), 8) as datetime), 9), 14), ':000', ' ')) as endtime
, STUFF(STUFF(active_start_date, 5, 0, '/'), 8, 0, '/') as schedule_start_date
, STUFF(STUFF(active_end_date, 5, 0, '/'), 8, 0, '/') as schedule_end_date
 ,ja.next_scheduled_run_date
 ,CASE h.run_status WHEN 0 THEN 'Failed' WHEN 1 THEN 'Completed' WHEN 2 THEN 'Retry' WHEN 3 THEN 'Cancel' WHEN 4 THEN 'Running' END AS LastRunOutcome
       ,CASE
          WHEN h.run_duration > 0
          THEN
               (h.run_duration / 1000000) * (3600 * 24)
             + (h.run_duration / 10000 % 100) * 3600
             + (h.run_duration / 100 % 100) * 60
             + (h.run_duration % 100)
          ELSE
             NULL
       END AS LastRunDuration
FROM msdb.dbo.sysjobs SJ
LEFT Join [tempdb].[dbo].[JobHistoryInformation] x
ON x.job_id = SJ.job_id
LEFT JOIN msdb.dbo.sysjobschedules SJS
ON SJ.job_id = SJS.job_id
LEFT JOIN msdb.dbo.sysschedules SS
ON SJS.schedule_id = SS.schedule_id
LEFT OUTER JOIN msdb.dbo.sysjobhistory h ON x.job_id = h.job_id AND x.last_run_date = h.run_date
          AND x.last_run_time = h.run_time AND h.step_id = 0
LEFT OUTER JOIN msdb.dbo.sysjobactivity ja on ja.job_history_id=h.instance_id and ja.job_id=SJ.job_id
) TEMPTA 

SQL Agent Job Error CMDEXEC subsystem failed to load

We have been recently migrating a lot of physical clusters to virtual. The quickest way to move sql agent jobs was to restore MSDB database. To validate if jobs were in order we executed our System Backup job and surprisingly it went in ‘Suspended’ mode. Investigation for the failed job revealed:

[LOG] Step 1 of job ‘DatabaseBackup – SYSTEM_DATABASES – FULL’ (0xCE446B0C82AA3141B2898110806513A1) cannot be run because the CMDEXEC subsystem failed to load. The job has been suspended

Upon further investigation of the agent log:

1 2 3 4 5 6 7 8 9 10 11 12 13

exec xp_readerrorlog 0,2 2015-04-09 14:50:22.000 1 [125] Subsystem 'ActiveScripting' could not be loaded (reason: The specified module could not be found) 2015-04-09 14:50:22.000 1 [125] Subsystem 'CmdExec' could not be loaded (reason: The specified module could not be found) 2015-04-09 14:50:22.000 1 [125] Subsystem 'Snapshot' could not be loaded (reason: The specified module could not be found) 2015-04-09 14:50:22.000 1 [125] Subsystem 'LogReader' could not be loaded (reason: The specified module could not be found) 2015-04-09 14:50:22.000 1 [125] Subsystem 'Distribution' could not be loaded (reason: The specified module could not be found) 2015-04-09 14:50:22.000 1 [125] Subsystem 'Merge' could not be loaded (reason: The specified module could not be found) 2015-04-09 14:50:22.000 1 [125] Subsystem 'QueueReader' could not be loaded (reason: The specified module could not be found) 2015-04-09 14:50:22.000 1 [125] Subsystem 'ANALYSISQUERY' could not be loaded (reason: The specified module could not be found) 2015-04-09 14:50:22.000 1 [125] Subsystem 'ANALYSISCOMMAND' could not be loaded (reason: The specified module could not be found) 2015-04-09 14:50:22.000 1 [125] Subsystem 'SSIS' could not be loaded (reason: The specified module could not be found) 2015-04-09 14:50:22.000 1 [125] Subsystem 'PowerShell' could not be loaded (reason: The specified module could not be found)

Don’t panic if you see your sql agent job error stating xxxxx ‘subsytem failed to load’. It certainly does not mean your SQL world is crashing. All it means is the location of the binary files was changed. This was first discovered in SQL2005 and well documented in KB903205. In total there are 11 subsystems as per my testing for SQL 2008/R2 & 2012. Here is the list:

Test Scenario

Migrating MSDB from SQL instances of 2008R2, 2012  –> SQL 2008R2, 2012

Fix

First thing we need to check is the syssubsystem table and determine the location of the dll’s.

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/*This will show the description for each subsystem*/ select ss.subsystem as Subsystem,sm.text as Description,ss.subsystem_dll, ss.agent_exe from msdb.dbo.syssubsystems ss inner join sys.messages sm on ss.description_id = sm.message_id where sm.language_id = 1033 /*This will skip description*/ select * from msdb.dbo.syssubsystems

You will need to pay attention to subsystem_dll column. Check if the files exist in the location. In our case, the old cluster pointed to S:\Program Files\Microsoft SQL Server\MSSQL10_50.xxx\MSSQL\binn\SQLCMDSS.DLL  and on the new cluster it was on C:\Program Files\Microsoft SQL Server\MSSQL10_50.xxx\MSSQL\binn\SQLCMDSS.DLL

In order to do this seamlessly run the following command followed by restart of sql agent

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sp_configure "allow updates",1 reconfigure with override go update msdb.dbo.syssubsystems set subsystem_dll = replace(subsystem_dll,'S:\Program Files','C:\Program Files')   from msdb.dbo.syssubsystems where subsystem_dll like 'S:\Program Files%' go sp_configure "allow updates", 0 reconfigure with override

If you do not like messing with MSDB and want your SQL Jobs to be moved between instances, there is an excellent article by Ahmad Osama on  move jobs using powershell