SQL SERVER : How to List All Email Subscription configured in SSRS ?

Often I used to get request from my business managers to get a list of all subscriptions configured in SSRS (SQL Server Reporting Service) along with email distribution list. I did not find any option in report server report manager interface to achieve this. I usually run the below query on the reporting server repository database to get the list.

USE REPORTSERVER_REPOSITORY
GO
DECLARE @Subscriptions TABLE (
                Report_OID  UNIQUEIDENTIFIER,
                ToList      VARCHAR(8000),
                CCList      VARCHAR(8000),
                BCCList     VARCHAR(8000),
                SubjectLine VARCHAR(8000))DECLARE @ExtensionSettings XML
DECLARE @Report_OID UNIQUEIDENTIFIER
DECLARE @idoc  INT
DECLARE SubscriptionList CURSOR FOR
SELECT Report_OID,ExtensionSettings 
    FROM subscriptionsOPEN SubscriptionList
    FETCH NEXT     FROM SubscriptionList INTO @Report_OID ,@ExtensionSettings
     WHILE (@@FETCH_STATUS=0)
    BEGIN
    EXEC sp_xml_preparedocument @idoc OUTPUT, @ExtensionSettings
    INSERT INTO @Subscriptions
        SELECT @Report_OID,[TO],[CC],[BCC],[Subject]
        FROM
        (
        SELECT *
            FROM OPENXML (@idoc, '/ParameterValues/ParameterValue')
                    WITH (Name NVARCHAR(100) 'Name',
                        Value NVARCHAR(100) 'Value')
        ) AS SourceTable
                pivot
        (
                    MAX(value) FOR [Name] IN ([TO],[BCC],[CC],[Subject])
        ) AS pivottable
    EXEC sp_xml_removedocument @idoc
   FETCH NEXT  FROM SubscriptionList INTO @Report_OID ,@ExtensionSettings

    END
            CLOSE SubscriptionList
            DEALLOCATE SubscriptionList

SELECT c.path,c.name,s.Tolist,s.cclist,s.bcclist,s.subjectline    FROM 
Catalog c INNER JOIN @Subscriptions  s ON c.ItemID = s.Report_OID    ORDER BY [path], Name

This will list the all reports configured for subscriptions with following details of Report Path, Report Name, ToList,CCList,BCCList and subject line of email.


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SQL Server: Part 4 : Approaching Database Server Performance Issue

In the last three parts, we have discussed about different queries that can be used to list the current state of the database server. In this post let us discuss about listing execution stats from the plan cache.

The below query will help us to list the CPU intensive queries from your  plan cache.

/*****************************************************************************************
List heavy query based on CPU/IO. Change the order by clause appropriately
******************************************************************************************/
SELECT TOP 20
DB_NAME(qt.dbid) AS DatabaseName
,DATEDIFF(MI,creation_time,GETDATE()) AS [Age of the Plan(Minutes)]
,last_execution_time AS [Last Execution Time]
,qs.execution_count AS [Total Execution Count]
,CAST((qs.total_elapsed_time) / 1000000.0 AS DECIMAL(28,2)) [Total Elapsed Time(s)]
,CAST((qs.total_elapsed_time ) / 1000000.0/ qs.execution_count AS DECIMAL(28, 2)) AS [Average Execution time(s)]
,CAST((qs.total_worker_time) / 1000000.0 AS DECIMAL(28,2)) AS [Total CPU time (s)]
,CAST(qs.total_worker_time * 100.0 / qs.total_elapsed_time AS DECIMAL(28,2)) AS [% CPU]
,CAST((qs.total_elapsed_time - qs.total_worker_time)* 100.0 /qs.total_elapsed_time AS DECIMAL(28, 2)) AS [% Waiting]
,CAST((qs.total_worker_time) / 1000000.0/ qs.execution_count AS DECIMAL(28, 2)) AS [CPU time average (s)]
,CAST((qs.total_physical_reads) / qs.execution_count AS DECIMAL(28, 2)) AS [Avg Physical Read]
,CAST((qs.total_logical_reads) / qs.execution_count AS DECIMAL(28, 2))  AS [Avg Logical Reads]
,CAST((qs.total_logical_writes) / qs.execution_count AS DECIMAL(28, 2)) AS [Avg Logical Writes]
,max_physical_reads
,max_logical_reads
,max_logical_writes
, SUBSTRING (qt.TEXT,(qs.statement_start_offset/2) + 1,((CASE WHEN qs.statement_end_offset = -1
   THEN LEN(CONVERT(NVARCHAR(MAX), qt.TEXT)) * 2
   ELSE qs.statement_end_offset
   END - qs.statement_start_offset)/2) + 1) AS [Individual Query]
, qt.TEXT AS [Batch Statement]
, qp.query_plan
FROM SYS.DM_EXEC_QUERY_STATS qs
CROSS APPLY SYS.DM_EXEC_SQL_TEXT(qs.sql_handle) AS qt
CROSS APPLY SYS.DM_EXEC_QUERY_PLAN(qs.plan_handle) qp
WHERE qs.total_elapsed_time > 0
ORDER BY 
[Total CPU time (s)] 
--[Avg Physical Read]
--[Avg Logical Reads]
--[Avg Logical Writes]
--[Total Elapsed Time(s)]
--[Total Execution Count]
DESC

Let us discuss the output columns.

Column Name	Description
DatabaseName	Database Context of the execution plan.
Age of the Plan(Minutes)	Age of the plan in the plan cache in minutes.
Last Execution Time	Date and Time of the last execution of this plan.
Total Execution Count	Total number of execution after the last compilation Or Total number of execution in the last [Age of the Plan(Minutes)] (since it was last compiled)
Total Elapsed Time(s)	Total time (second) took to execute this plan [Total Execution Count] times
Average  Execution time(s)	Average Time(seconds) took for single execution of this plan
Total CPU time (s)	Total CPU time(seconds) took to  execute this plan [Total Execution Count] times
% CPU	Percentage of CPU time compared to  [Total Elapsed Time(s)]
% Waiting	Percentage of waiting time(wait for resource)  compared to  [Total Elapsed Time(s)]
CPU time  average (s)	Average CPU time (Seconds) used for single exection
Avg Physical Read	Average number of Physical read for single execution
Avg Logical Reads	Average number of Logical read for single execution
Avg Logical Writes	Average number of Logical writes for single execution
max_physical_reads	Maximum number of physical reads that this plan has ever performed during a single execution.
max_logical_reads	Maximum number of logical reads that this plan has ever performed during a single execution.
max_logical_writes	Maximum number of logical writes that this plan has ever performed during a single execution.
Individual Query	Part of Batch Statement
Batch Statement	Batch Query
query_plan	XML execution . On clicking this we can see the graphical execution plan

I used to  analyse  the first five to ten records ( in each category by changing the order by clause) to see  procedures implementation. Most of the time I used to find some thing wrong with the procedure  like unnecessary temp table usage, distinct clause , cursors, table joining with out proper joining condition,no proper indexing etc. The other issue usually happen is, enormous calls to database for single procedure (CPU cost and execution time might less). This might be a wrong implementation, which should be fixed by discussing with development team. Usually this can be fixed by adding some types of caching  in application.Some time calls to the database is only to check if there is any change in the result data. Some thing like if there is new records in a table, it should be processed immediately. To achieve this, application might be querying the table to find the unprocessed record multiple time in a second, This can be fixed by implementing some kind of asynchronous call to the application by the application which inserts the data into this table or by implementing the notification event using SqlDependency available in the .Net frame work.

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SQL Server: Part 3 : Approaching Database Server Performance Issue

In the last post, we have discussed the script to list the sessions which are waiting for resource or currently running. In this post let us see how to list the blocking sessions with required information.  

******************************************************************************************/
CREATE FUNCTION [dbo].dba_GetStatementForSpid
(  
   @spid SMALLINT  
)  
RETURNS NVARCHAR(4000)  
BEGIN  
   DECLARE @SqlHandle BINARY(20)  
   DECLARE @SqlText NVARCHAR(4000)  
   SELECT @SqlHandle = sql_handle   
      FROM sys.sysprocesses WITH (nolock) WHERE   spid = @spid  
   SELECT @SqlText = [text] FROM   
      sys.dm_exec_sql_text(@SqlHandle)  
   RETURN @SqlText  
END  
GO

/*****************************************************************************************
STEP 4: List the current blocking session information
****************************************************************************************/

SELECT
es.session_id,
es.HOST_NAME,
DB_NAME(database_id) AS DatabaseName, 
CASE WHEN es.program_name LIKE '%SQLAgent - TSQL JobStep%' THEN (SELECT 'SQL AGENT JOB: '+name FROM msdb..sysjobs WHERE job_id=MASTER.DBO.ConvertStringToBinary (LTRIM(RTRIM((SUBSTRING(es.program_name,CHARINDEX('(job',es.program_name,0)+4,35)))))) 
ELSE es.program_name END  AS program_name ,
es.login_name ,
bes.session_id AS Blocking_session_id,
MASTER.DBO.dba_GetStatementForSpid(es.session_id) AS [Statement],
bes.HOST_NAME AS Blocking_hostname,
CASE WHEN Bes.program_name LIKE '%SQLAgent - TSQL JobStep%' THEN
(SELECT 'SQL AGENT JOB: '+name FROM msdb..sysjobs WHERE job_id=
MASTER.DBO.ConvertStringToBinary 
(LTRIM(RTRIM((SUBSTRING(Bes.program_name,CHARINDEX('(job',es.program_name,0)+4,35))))))
ELSE Bes.program_name END  AS Blocking_program_name,
bes.login_name AS Blocking_login_name,
  MASTER.DBO.dba_GetStatementForSpid(bes.session_id ) AS [Blocking Statement]
FROM sys.dm_exec_requests S 
INNER JOIN sys.dm_exec_sessions  es ON es.session_id=s.session_id
INNER JOIN sys.dm_exec_sessions  bes ON bes.session_id=s.blocking_session_id



This script will list the blocked and blocking statement information and will be helpful to troubleshoot. Below script will help us to identify the sessions which have an open transaction but not active . That is, a sessions with an open transaction but not running any statement in the last 30 seconds.

/*****************************************************************************************

STEP 4: List the Open session with transaction which is not active
****************************************************************************************/
SELECT es.session_id, 
es.login_name, 
es.HOST_NAME, 
DB_NAME(SP.dbid) AS DatabaseName,
sp.lastwaittype,
est.TEXT,cn.last_read, 
cn.last_write,
CASE WHEN es.program_name LIKE '%SQLAgent - TSQL JobStep%' THEN(SELECT 'SQL AGENT JOB: '+name FROM msdb..sysjobs WHERE job_id=MASTER.DBO.ConvertStringToBinary (LTRIM(RTRIM((SUBSTRING(es.program_name,CHARINDEX('(job',es.program_name,0)+4,35)))))
)ELSE es.program_name END  AS program_name 
FROM sys.dm_exec_sessions es
INNER JOIN sys.dm_tran_session_transactions st ON es.session_id = st.session_id                INNER JOIN sys.dm_exec_connections cn ON es.session_id = cn.session_id 
INNER JOIN sys.sysprocesses SP ON SP.spid=es.session_id                 
LEFT OUTER JOIN sys.dm_exec_requests er  ON st.session_id = er.session_id   
AND er.session_id IS NULL             
CROSS APPLY sys.dm_exec_sql_text(cn.most_recent_sql_handle) est                
WHERE (DATEDIFF(SS,cn.last_read,GETDATE())+DATEDIFF(SS,cn.last_write,GETDATE()))>30
AND lastwaittype NOT IN ('BROKER_RECEIVE_WAITFOR' ,'WAITFOR')                                  GO


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SQL Server: Part 2 : Approaching Database Server Performance Issues

In the Part 1, we have seen how quickly we can check the runnable task and I/O pending task on an SQL server instance. This  is very light weight script and it will give the result even if the server is under pressure and will give an over all state of the server at that moment.

The next step (Step2)  in my way of diagnosing is to check the session that are waiting of any resources. Below script will help us. This query required a function as prerequisite,  which will help us to display the SQL server agent job name if the session started by SQL server agent.

/*****************************************************************************************
           PREREQUISITE FUNCTION
******************************************************************************************/
USE MASTER
GO 
CREATE FUNCTION ConvertStringToBinary  ( @hexstring  VARCHAR(100)
)  RETURNS BINARY(34)  AS
BEGIN

   RETURN(SELECT CAST('' AS XML).value('xs:hexBinary( substring(sql:variable("@hexstring"), sql:column("t.pos")) )', 'varbinary(max)')
   FROM (SELECT CASE SUBSTRING(@hexstring, 1, 2) WHEN '0x' THEN 3 ELSE 0 END) AS t(pos))  
END
/***************************************************************************************
STEP 2: List the session which are currently waiting for resource
****************************************************************************************/
SELECT node.parent_node_id AS Node_id,
es.HOST_NAME,
es.Login_name,
CASE WHEN es.program_name LIKE '%SQLAgent - TSQL JobStep%' THEN
         (
          SELECT 'SQL AGENT JOB: '+name FROM msdb..sysjobs WHERE job_id=
          MASTER.DBO.ConvertStringToBinary (LTRIM(RTRIM((SUBSTRING(es.program_name,CHARINDEX('(job',es.program_name,0)+4,35)))))
          )
    ELSE es.program_name END  AS [Program Name] ,
DB_NAME(er.database_id) AS DatabaseName,
er.session_id, 
wt.blocking_session_id,
wt.wait_duration_ms,
wt.wait_type,
wt.NoThread ,
er.command,
er.status,
er.wait_resource,
er.open_transaction_count,
er.cpu_time,
er.total_elapsed_time AS ElapsedTime_ms,
er.percent_complete ,
er.reads,
er.writes,
er.logical_reads,
wlgrp.name AS ResoursePool              ,
SUBSTRING   (sqltxt.TEXT,(er.statement_start_offset/2) + 1,          
            ((CASE WHEN er.statement_end_offset = -1          
             THEN LEN(CONVERT(NVARCHAR(MAX), sqltxt.TEXT)) * 2          
             ELSE er.statement_end_offset          
            END - er.statement_start_offset)/2) + 1) AS [Individual Query], 
sqltxt.TEXT AS [Batch Query]                
FROM (SELECT session_id, SUM(wait_duration_ms) AS 
wait_duration_ms,wait_type,blocking_session_id,COUNT(*) AS NoThread 
FROM  SYS.DM_OS_WAITING_TASKS  GROUP BY session_id, wait_type,blocking_session_id) wt 
INNER JOIN SYS.DM_EXEC_REQUESTS  er ON wt.session_id=er.session_id INNER JOIN SYS.DM_EXEC_SESSIONS es ON es.session_id= er.session_id
INNER JOIN SYS.DM_RESOURCE_GOVERNOR_WORKLOAD_GROUPS wlgrp ON wlgrp.group_id=er.group_id          
INNER JOIN  (SELECT  os.parent_node_id ,task_address FROM SYS.DM_OS_SCHEDULERS  OS INNER JOIN 
SYS.DM_OS_WORKERS  OSW ON OS.scheduler_address=OSW.scheduler_address 
WHERE os.status='VISIBLE ONLINE' GROUP BY os.parent_node_id ,task_address ) node   
ON node.task_address=er.task_address
CROSS APPLY SYS.DM_EXEC_SQL_TEXT(er.sql_handle) AS sqltxt
WHERE sql_handle IS NOT NULL AND wt.wait_type NOT IN ('WAITFOR','BROKER_RECEIVE_WAITFOR')
GO

The Description of the columns in the result are given below. 

Column Name	Description
Node Id	NUMA node id . Can be mapped to the node id of the scheduler query.
Host_Name	Name of the computer from the connection is originated.
Login Name	Login used in the session to connect the database server
Program Name	Name of the program/application using this session. You can set the application name in the connection string. If this session is part of SQL server agent job, it will show the job name
Database Name	Current database  of the session
Session Id	The session id
Blocking Session id	Session id blocking statement
wait_duration_ms	Total wait time for this wait type, in milliseconds. This time is inclusive of signal wait time
wait_type	Name of the wait type like SLEEP_TASK,CXPACKET etc
No of Thread	No of threads running on this session. If the session is in parallel execution
Command	Identifies the current type of command that is being processed like Select,insert,update,delete etc
Status	Status of the request. This can be of the following: Background,Running,Runnable,Sleeping and Suspended
Wait Resource	Resource for which the request is currently waiting
Open Transaction count	Number of transaction opened in this session
Cpu Time	CPU time in milliseconds that is used by the request.
Total Elapsed Time	Total time elapsed in milliseconds since the request arrived
Percent_Complete	Percent of work completed for certain operations like backup,restore rollback etc.
Reads	Number of reads performed by this request.
Writes	Number of writes performed by this request.
logical_reads	Number of logical reads performed by this request.
ResoursePool	Name of of Resource Governor Pool
Individual Query	current statement of the batch running on this session.
Batch Query	Current batch (procedure/set of sql statement) running on this session.

If there is a session with very long wait_duration_ms and  not blocked by any other session and  not going away from the list in the subsequent execution of the same query, I will look into the program name,host name,login name and the statement that is running which will give me an idea about the session.Based on all these information, I might decide to kill that session and look into the implementation of that SQL batch. If the session is blocked, I will look into the blocking session using a different script which I will share later.(Refer this post)

The next step (Step 3)  is to list all session which are currently running on the server. I use below query to do that.

/***************************************************************************************

STEP 3: List the session which are currently waiting/running
****************************************************************************************/SELECT node.parent_node_id AS Node_id,
es.HOST_NAME,
es.login_name,
CASE WHEN es.program_name LIKE '%SQLAgent - TSQL JobStep%' THEN
(SELECT 'SQL AGENT JOB: '+name FROM msdb..sysjobs WHERE job_id=ADMIN.DBO.ConvertStringToBinary (LTRIM(RTRIM((SUBSTRING(es.program_name,CHARINDEX('(job',es.program_name,0)+4,35)))))
)ELSE es.program_name END  AS program_name ,
DB_NAME(er.database_id) AS DatabaseName,
er.session_id, 
wt.blocking_session_id,
wt.wait_duration_ms,
wt.wait_type,
wt.NoThread ,
er.command,
er.status,
er.wait_resource,
er.open_transaction_count,
er.cpu_time,
er.total_elapsed_time AS ElapsedTime_ms,
er.percent_complete ,
er.reads,er.writes,er.logical_reads,
wlgrp.name AS ResoursePool              ,
SUBSTRING (sqltxt.TEXT,(er.statement_start_offset/2) + 1,                
((CASE WHEN er.statement_end_offset = -1                
THEN LEN(CONVERT(NVARCHAR(MAX), sqltxt.TEXT)) * 2                
ELSE er.statement_end_offset                
END - er.statement_start_offset)/2) + 1) AS [Individual Query],
sqltxt.TEXT AS [Batch Query]                
FROM 
SYS.DM_EXEC_REQUESTS  er INNER JOIN SYS.DM_EXEC_SESSIONS es ON es.session_id= er.session_id
INNER JOIN SYS.DM_RESOURCE_GOVERNOR_WORKLOAD_GROUPS wlgrp ON wlgrp.group_id=er.group_id          
INNER JOIN  (SELECT  os.parent_node_id ,task_address FROM SYS.DM_OS_SCHEDULERS  OS 
INNER JOIN SYS.DM_OS_WORKERS  OSW ON OS.scheduler_address=OSW.scheduler_address
WHERE os.status='VISIBLE ONLINE' GROUP BY os.parent_node_id ,task_address ) node ON node.task_address=er.task_address
LEFT JOIN 
(SELECT session_id, SUM(wait_duration_ms) AS 
wait_duration_ms,wait_type,blocking_session_id,COUNT(*) AS NoThread 
FROM  SYS.DM_OS_WAITING_TASKS  GROUP BY session_id, wait_type,blocking_session_id) wt 
ON wt.session_id=er.session_id
CROSS apply SYS.DM_EXEC_SQL_TEXT(er.sql_handle) AS sqltxt
WHERE sql_handle IS NOT NULL AND ISNULL(wt.wait_type ,'') NOT IN 
('WAITFOR','BROKER_RECEIVE_WAITFOR')
ORDER BY er.total_elapsed_time DESC

GO

The columns are same as we discussed in step 2 . I used to analyse the sessions with  more total_elapsed_time and take appropriate actions like killing the session and look into the implementation. In most of the scenario (where server was running perfectly but all off sudden it become standstill) , I will be able fix the issue by following these steps.  In the next part let us discuss  about blocking session and session with open transaction which is not active.


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SQL Server: Part 1 : Approaching Database Server Performance Issues

When you work as DBA, many people will approach you with a complaint like "Application is taking ages to load the data on a page,could you please check something going wrong with database server?" There might be hundred of other reason for slowness of the page.It might be a Problem with application server,network issues,really a bad implementation or problem with database server due to generation of huge report /job running at that moment. What ever be the issue, database gets the blame first. Then it is our responsibility to cross check the server state. 

Let us discuss how we can approach this issue. I use following script to diagnose  the issues. The first script which I will run against server is given below:

SELECT 

parent_node_id                  AS Node_Id,
COUNT(*)                        AS [No.of CPU In the NUMA],
SUM(COUNT(*)) OVER()            AS [Total No. of CPU],
SUM(runnable_tasks_count )      AS [Runnable Task Count], 
SUM(pending_disk_io_count)                    AS [Pending disk I/O count],
SUM(work_queue_count)          AS  [Work queue count]
FROM sys.dm_os_schedulers WHERE status='VISIBLE ONLINE' GROUP BY parent_node_id



This will give following information. 

• Number of records in the output will be equal to number of NUMA nodes (if it is fetching only one record , it is not a NUMA supported server)
• Node_id : NUMA node id . Can be mapped into the later scripts.
• No.of CPU in the NUMA : Total number of CPU assigned to the specific NUMA node or the number of schedulers.
• Total No. of CPU : Total No. of CPU available in the server.If you have set the affinity mask, total number of CPU assigned to this instance.
• Runnable Task Count: Number of workers, with tasks assigned to them, that are waiting to be scheduled on the runnable queue. Is not nullable. In short number of request in runnable queue.To understand more about Runnable queue , read my earlier post.
• Pending disk I/O count : Number of pending I/Os that are waiting to be completed. Each scheduler has a list of pending I/Os that are checked to determine whether they have been completed every time there is a context switch. The count is incremented when the request is inserted. This count is decremented when the request is completed.
• Work queue count: Number of tasks in the pending queue. These tasks are waiting for a worker to pick them up.

I have scheduled this scrip to store the output this query in a table for two days in the interval of 10 minutes. That will give baseline data about what is normal in your environment. In my environment people will start complaining once the Runnabable Task Count of  most of the nodes goes beyond 10 consistently. In normal scenario, the value of Runnabable Task Count will be always below 10 on each node and never seen a value greater than 0 for work queue count field.This will give a picture of current state of the system.If the output of this step is normal, we are safe to an extent, the slow response might be issue which might be beyond our control or a blocking and slow response is only for a couple of screens(sessions) not for entire system. 

This is the first step in my way of diagnosing. I will explain the further steps in my next post.

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