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T-SQL Script to Check the Native Compressed backup file size and Backup Compression Ratio

First of all make sure backup compression is enabled on the SQL Server. You can execute below query to check the backup compression.

select name,[description],value_in_use from sys.configurations where name like '%backup%'

Execute below script to check the compressed backup file size and backup compression ratio.

Declare @FromDate as datetime
-- Specify the from date value
set @FromDate = GETDATE() -1

SELECT  
   CONVERT(CHAR(100), SERVERPROPERTY('Servername')) AS SQLServerName, 
   msdb.dbo.backupset.database_name,  
   CASE msdb..backupset.type  
       WHEN 'D' THEN 'Database'  
       WHEN 'L' THEN 'Log'  
       WHEN 'I' THEN 'Differential'  
   END AS backup_type,  
   msdb.dbo.backupset.backup_start_date,  
   msdb.dbo.backupset.backup_finish_date, 
   msdb.dbo.backupset.expiration_date, 
   DATEDIFF (SECOND, msdb.dbo.backupset.backup_start_date, msdb.dbo.backupset.backup_finish_date) 'Backup Elapsed Time (sec)',
   msdb.dbo.backupset.compressed_backup_size AS 'Compressed Backup Size in KB',
  (msdb.dbo.backupset.compressed_backup_size/1024/1024) AS 'Compress Backup Size in MB',
   CONVERT (NUMERIC (20,3), (CONVERT (FLOAT, msdb.dbo.backupset.backup_size) /CONVERT (FLOAT, msdb.dbo.backupset.compressed_backup_size))) 'Compression Ratio',
   CASE msdb..backupset.type  
       WHEN 'D' THEN 'Database'  
       WHEN 'L' THEN 'Log'  
   END AS backup_type,  
   msdb.dbo.backupset.backup_size,  
   msdb.dbo.backupmediafamily.logical_device_name,  
   msdb.dbo.backupmediafamily.physical_device_name,   
   msdb.dbo.backupset.name AS backupset_name, 
   msdb.dbo.backupset.description 
FROM   msdb.dbo.backupmediafamily  
   INNER JOIN msdb.dbo.backupset ON msdb.dbo.backupmediafamily.media_set_id = msdb.dbo.backupset.media_set_id 
WHERE 
CONVERT(datetime, msdb.dbo.backupset.backup_start_date, 102) >= @FromDate
AND msdb.dbo.backupset.backup_size > 0 
ORDER BY  
   msdb.dbo.backupset.database_name, 
   msdb.dbo.backupset.backup_finish_date

SQL Server – Backup Verification Script – Based on conditions

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Problem: There are scenarios where you have to verify the multiple SQL Server instances backup within limited time frame whether it meet your organization backup criteria standards or not.

Solution:
You can execute below T-SQL script to check the backup status as per your organization standard by assigning backup conditions value to backup criteria variable. You can execute below script either by connecting each SQL Server Instance or execute it by registering all the SQL Server Instances in Central Management Server (CMS).

Below T-SQL Script work with all the versions of MSSQL Server and verify FULL, Differential and Transaction Log Backup. It will check the max backup date and evaluate result based on condition as backup is Passed or Not.

Backup Verification Script will return below values. Column names are self-explanatory.
• SQLInstanceName
• DatabaseName
• db_create_ddate
• DB_Recovery_Model
• dbstatus
• windowsservername
• productversion
• productlevel
• edition
• current_datetime
• last_full_backup_date
• last_diff_backup_date
• last_tran_backup_date
• days_since_last_full_backup
• days_since_last_diff_backup
• hours_since_last_tranlog_backup
• Full_Backup_Stauts
• Diff_Backup_Stauts
• Log_Backup_Stauts
• full_backup_location
• diff_backup_location
• tlog_backup_location

You have to specify the backup condition based on your organization standard by assigning values to below variables.

declare @full_backup_criteria_in_days int
declare @diff_backup_criteria_in_days int
declare @log_backup_criteria_in_hours int

-- specify the backup criteria
set @full_backup_criteria_in_days = 7 -- 7 day older Full Backup is Pass 
set @diff_backup_criteria_in_days = 1 -- 1 day older Diff Backup is Pass 
set @log_backup_criteria_in_hours = 2 -- 2 hours older Log Backup is Pass

Complete Backup Verification Script

declare @full_backup_criteria_in_days int
declare @diff_backup_criteria_in_days int
declare @log_backup_criteria_in_hours int

-- specify the backup criteria
set @full_backup_criteria_in_days = 7 -- 7 day older Full Backup is Pass 
set @diff_backup_criteria_in_days = 1 -- 1 day older Diff Backup is Pass 
set @log_backup_criteria_in_hours = 2 -- 2 hours older Log Backup is Pass

select     
           serverproperty('servername') as SQLInstanceName,
           quotename(bkup_full.[database_name]) as DatabaseName,
            ( select    sdb.crdate
              from      [master]..[sysdatabases] sdb
              where     sdb.name = bkup_full.[database_name]
            ) as [db_create_ddate],           
           databasepropertyex(bkup_full.[database_name],'recovery')  as DB_Recovery_Model,
           databasepropertyex(bkup_full.[database_name],'status')  as dbstatus,       
           case serverproperty('isclustered') 
                        when 1 then cast(serverproperty('computernamephysicalnetbios') as varchar)
                        when 0 then cast(serverproperty('machinename') as varchar)
           end as windowsservername,
           serverproperty('productversion') as productversion,
           serverproperty('productlevel') as productlevel,
           serverproperty('edition') as edition,

           current_timestamp as current_datetime,
		   
		   bkup_full.[backup_finish_date] as [last_full_backup_date],           
		   bkup_diff.[backup_finish_date] as [last_diff_backup_date] ,
		   bkup_log.[backup_finish_date] as [last_tran_backup_date] ,

           datediff(dd, bkup_full.[backup_finish_date], current_timestamp) as [days_since_last_full_backup] ,
           datediff(dd, bkup_diff.[backup_finish_date], current_timestamp) as [days_since_last_diff_backup] ,
           datediff(hh, bkup_log.[backup_finish_date], current_timestamp) as [hours_since_last_tranlog_backup] ,
            
           case 
                        when datediff(dd, bkup_full.[backup_finish_date], current_timestamp) <= @full_backup_criteria_in_days  
                        then 'Pass'
                        else 'Fail'
                        end as Full_Backup_Stauts,
            
            case 
                        when datediff(dd, bkup_diff.[backup_finish_date], current_timestamp) <= @diff_backup_criteria_in_days  then 'Pass'
                        else case when quotename(bkup_full.[database_name]) IN ('[master]') then 'N/A' else 'Fail' end                        
                        end as Diff_Backup_Stauts,

            case 
                        when datediff(hh, bkup_log.[backup_finish_date], current_timestamp) <= @log_backup_criteria_in_hours  then 'Pass'
                        else case when databasepropertyex(bkup_full.[database_name],'recovery') = 'SIMPLE' then 'N/A' else 'Fail' end                        
            end as Log_Backup_Stauts,            

            ( select top 1 [physical_device_name]
              from      [msdb]..[backupmediafamily] bkup_media_family
              where     bkup_media_family.[media_set_id] = bkup_full.[media_set_id]
            ) as [full_backup_location] ,
            ( select top 1  [physical_device_name]
              from      [msdb]..[backupmediafamily] bkup_media_family
              where     bkup_media_family.[media_set_id] = bkup_diff.[media_set_id]
            ) as [diff_backup_location] ,
            ( select top 1  [physical_device_name]
              from      [msdb]..[backupmediafamily] bkup_media_family
              where     bkup_media_family.[media_set_id] = bkup_log.[media_set_id]
            ) as [tlog_backup_location]
         
                             
    from    [msdb]..[backupset] as bkup_full
            left join [msdb]..[backupset] as bkup_log on bkup_log.[database_name] = bkup_full.[database_name]
                                                       and bkup_log.[server_name] = bkup_full.[server_name]
                                                       and bkup_log.[type] = N'L'
                                                       and bkup_log.[backup_finish_date] = ( (select  max([backup_finish_date])
                                                                                            from    [msdb]..[backupset] b2
                                                                                            where   b2.[database_name] = bkup_full.[database_name]
                                                                                                    and b2.[server_name] = bkup_full.[server_name]
                                                                                                    and b2.[type] = N'L') )
            left join [msdb]..[backupset] as bkup_diff on bkup_diff.[database_name] = bkup_full.[database_name]
                                                       and bkup_diff.[server_name] = bkup_full.[server_name]
                                                       and bkup_diff.[type] = N'I'
                                                       and bkup_diff.[backup_finish_date] = ( (select max([backup_finish_date])
                                                                                            from    [msdb]..[backupset] b2
                                                                                            where   b2.[database_name] = bkup_full.[database_name]
                                                                                                    and b2.[server_name] = bkup_full.[server_name]
                                                                                                     and b2.[type] = N'I') )
    where   bkup_full.[type] = N'D'
            and bkup_full.[backup_finish_date] = ( (select  max([backup_finish_date])
                                                 from   [msdb]..[backupset] b2
                                                 where  b2.[database_name] = bkup_full.[database_name]
                                                        and b2.[server_name] = bkup_full.[server_name]
                                                        and b2.[type] = N'D') )
            and exists ( select [name]
                         from   [master]..[sysdatabases]
                         where  [name] = bkup_full.[database_name] )
            and bkup_full.[database_name] <> N'tempdb'

RESOURCE_SEMAPHORE WAIT – Performance Troubleshooting

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Recently I was involved in troubleshooting the performance issue. All the queries were running slow on SQL instance. Most of the queries usually complete in seconds and that day it was running more than 15 minutes and not return any output.

I have followed below approach to fix this issue.
Step 1: Checked for the blocking if there is any on the SQL instace but didn’t find any.

select * from sys.sysprocesses where blocked <> 0

Step 2: Checked for the active sessions on the server. To find out if there is any session which in KILLED/Rollback state but didn’t find out any. Sessions in KILLED/Rollback states are resource incentive sessions based on different conditions.

sp_who2 active

Step 3: Checked for the overall wait types on the SQL Server and found RESOURCE_SEMAPHORE and Page IO related waits.

SELECT TOP 10
        wait_type ,
        max_wait_time_ms wait_time_ms ,
        signal_wait_time_ms ,
        wait_time_ms - signal_wait_time_ms AS resource_wait_time_ms ,
        100.0 * wait_time_ms / SUM(wait_time_ms) OVER ( )
                                    AS percent_total_waits ,
        100.0 * signal_wait_time_ms / SUM(signal_wait_time_ms) OVER ( )
                                    AS percent_total_signal_waits ,
        100.0 * ( wait_time_ms - signal_wait_time_ms )
        / SUM(wait_time_ms) OVER ( ) AS percent_total_resource_waits
FROM    sys.dm_os_wait_stats
WHERE   wait_time_ms > 0
        AND wait_type NOT IN 
( 'SLEEP_TASK', 'BROKER_TASK_STOP', 'BROKER_TO_FLUSH',
  'SQLTRACE_BUFFER_FLUSH','CLR_AUTO_EVENT', 'CLR_MANUAL_EVENT', 
  'LAZYWRITER_SLEEP', 'SLEEP_SYSTEMTASK', 'SLEEP_BPOOL_FLUSH',
  'BROKER_EVENTHANDLER', 'XE_DISPATCHER_WAIT', 'FT_IFTSHC_MUTEX',
  'CHECKPOINT_QUEUE', 'FT_IFTS_SCHEDULER_IDLE_WAIT', 
  'BROKER_TRANSMITTER', 'FT_IFTSHC_MUTEX', 'KSOURCE_WAKEUP',
  'LAZYWRITER_SLEEP', 'LOGMGR_QUEUE', 'ONDEMAND_TASK_QUEUE',
  'REQUEST_FOR_DEADLOCK_SEARCH', 'XE_TIMER_EVENT', 'BAD_PAGE_PROCESS',
  'DBMIRROR_EVENTS_QUEUE', 'BROKER_RECEIVE_WAITFOR',
  'PREEMPTIVE_OS_GETPROCADDRESS', 'PREEMPTIVE_OS_AUTHENTICATIONOPS',
  'WAITFOR', 'DISPATCHER_QUEUE_SEMAPHORE', 'XE_DISPATCHER_JOIN',
  'RESOURCE_QUEUE' )
ORDER BY wait_time_ms DESC

Step 4: Analyzed the wait types, while analyzing the wait types I found the RESOURCE_SEMAPHORE wait type. Let’s see what is RESOURCE_SEMAPHORE wait type and what does it indicate.

RESOURCE SEMAPHORE SQL wait type “Occurs when a memory request for query cannot be granted immediately due to other concurrent queries or memory pressure, Resource Semaphore high waits and wait times may indicate excessive number of concurrent queries, or excessive memory request amounts”

Let’s query DMV to get more idea on Resource Semaphore wait. In the output of the below query output you have to check grantee_count and waiter_count column values, grantee_count is the number of queries which have their memory granted and the waiter_count is the number of queries which are waiting in queue to get memory

SELECT * FROM sys.dm_exec_query_resource_semaphores

Now let’s check queries waiting for memory using “sys.dm_exec_query_memory_grants” DMV. Columns grant_time and granted_memory_kb will be NULL for those queries which are waiting to get their requested memory

SELECT * FROM sys.dm_exec_query_memory_grants  where grant_time is null

I have also checked the “Memory Grants Pending” performance counter to get more idea. If Memory Grants Pending values is great than 0, than there is a problem.

SELECT OBJECT_NAME,cntr_value AS [Memory Grants Pending]
FROM sys.dm_os_performance_counters
WHERE OBJECT_NAME = 'MSSQL$MyInstance:Memory Manager'
AND counter_name = 'Memory Grants Pending'

Step 5 To resolve the issue immediately, as it was active-active cluster and there was memory available to allocate to SQL Server, I have increased the memory.

Long term fix
Find out the memory consuming queries and tune them
Schedule BULK Processing Jobs during off business hours
Make sure stats and indexes are up to date
If the server load increase, plan to add more memory

How to rerun the SQL Agent job step automatically in case of failure?

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How to rerun the SQL Agent job step automatically in case of failure?

Take an example of long running the job with the multiple steps where each steps has dependency of the previous steps successful execution. In case if any of the job step fails, entire job will fail and DBA has to manually run the job to complete it and job will run from the beginning.

There could be multiple reason of the job failure for example deadlock, network issue, requested backup file is not available as backup is still in progress etc.

You can avoid this situation using he job step advanced option Retry Attempts and Retry Interval (minutes)

Before the job step considered to have failed, you can set the number of times that the job step should be repeated using “Retry attempts” option. You can also use the Retry interval (minutes) option the number of minutes interval between retry attempts.

Default value of “Retry attempts” and “Retry interval (minutes)” is 0

For example if I will specify the “Retry attempts” to 3 and “Retry interval (minutes)” to 15 minutes, job step will re-run of up to 3 failure at 15 minutes interval.