WMI Tracing equivalent of SQL Server Profiler Traces

A lot of companies find the need to monitor all DDL and DML activity on the server for Compliance reasons. Though SQL Profiler Traces provides this functionality by using Stored Procedures and Functions. These system stored procedures can be used from within your own applications to create traces manually, instead of using SQL Server Profiler. This allows you to write custom applications specific to the needs of your enterprise. However, you might choose not to use this approach due to the overhead of running profiler traces on the server. You can use server side profiler traces which tend to have a lesser performance impact on the server. 

Another method is to use WMI Events to monitor SQL Server Events. Consider the following example, let’s say you want to monitor the SQL Server events for all Update Statistics Events. Then you can use script below to create the WMI Alert and also the job to put the event details into a SQL Server database table. 

<script> 

USE TestDB 

GO 

-- Creating the table to store the DDL Events 

CREATE TABLE [dbo].[UPD_STATS_Events]( 

[AlertTime] [datetime] NULL, 

[SPID] [int] NULL, 

[DBName] [nvarchar](100) NULL, 

[TextData] [nvarchar](max) NULL 

) ON [PRIMARY] 

GO 

-- Adding the job to run when the WMI Alert is raised 

EXEC msdb.dbo.sp_add_job @job_name=N'Capture Update Statistics Events', 

@enabled=1, 

@description=N'Job for responding to DDL events' ; 

GO 

-- Adding the job step 

EXEC msdb.dbo.sp_add_jobstep 

@job_name = N'Capture Update Statistics Events', 

@step_name=N'Insert data into Update Statistics Events table', 

@step_id=1, 

@on_success_action=1, 

@on_fail_action=2, 

@subsystem=N'TSQL', 

@command= N'INSERT INTO UPD_STATS_Events 

(AlertTime, Spid,DBName,TextData) 

VALUES (getdate(), $(ESCAPE_NONE(WMI(SPID))), 

''$(ESCAPE_SQUOTE(WMI(DatabaseName)))'', 

''$(ESCAPE_SQUOTE(WMI(TSQLCommand)))'')', 

@database_name=N'TestDB' ; 

GO 

-- Set the job server for the job to the current instance of SQL Server. 

EXEC msdb.dbo.sp_add_jobserver @job_name = N'Capture Update Stats Events' ; 

GO 

-- For the named instance you need to use \\.\root\Microsoft\SqlServer\ServerEvents\<INSTANCE NAME> 

EXEC msdb.dbo.sp_add_alert @name=N'Respond to Update Statistics Events', 

@wmi_namespace=N'\\.\root\Microsoft\SqlServer\ServerEvents\MSSQLSERVER', 

@wmi_query=N'SELECT * FROM UPDATE_STATISTICS', 

@job_name='Capture Update Statistics Events' ; 

GO

</script> 

You will have to give the SQL Agent account WMI Token replacement rights. You need to create a registry key in SQLAgent for this.
Add a Reg_DWORD HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL
Server\MSSQL.x\SQLServerAgent\AlertReplaceRuntimeTokens
and set it to 1.
and no SQLAgent restarts needed. 

Where x = the number of the SQL instance. This can be found out by looking under the regisry key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\Instance Names\SQL 

Whenever an update statistics task is fired against a database, the time when the command was executed, the SPID number, the database name and the T-SQL Command command associated with the event would be put into the table in the TestDB database. 

Service Broker should be enabled for the MSDB and the database in which you are storing the event details. 

Information about the namespaces can be found on MSDN. Also, you could use WMI Code Creator to browse through the namespace and the classes available and their properties. 

Furthermore, you can also use the WMI Event Watcher Task or the WMI Data Reader Task of SQL Server 2005 SSIS to perform the same.

The product has been patched with more recent updates

I have seen a few SQL Server 2005 Failover Clusters running into this issue. Recently, a KB Article was published explaining 2 methods (KB934749) to resolve this issue.

One scenario when you can run into this issue is when you have a SQL Server 2005 Failover Cluster patched with Service Pack 2 or higher and you add a new node to the Failover Cluster, you could run into the issue then.

Another scenario is that the SQL Server binaries on the one node got upgraded to a higher build but one of the member nodes was not upgraded due to some fatal error. But this is a very very rare scenario because SQL Server 2005 setup makes sure it patches all the member nodes where the SQL instance is not active before patching the node on which the SQL instance is installed.

SQL BPA – Part II

I have already blogged about this in a previous post of mine (Best Practice Analyzer) but I was recently working on the SQL Server 2005 version of the tool and thought that this deserved a second mention.

This tool has been enhanced a lot and provides a great deal more information than it’s SQL 2000 counterpart. This creates a XML data output file in your %appdata%/Microsoft/SQL BPA folder. This output can be imported using the SQL BPA UI and then a set of reports can be generated to check the following:

  • Gathers configuration information from an instance of SQL Server.
  • Performs specific tests on the instance of SQL Server.
  • Proactively verifies that the configuration is set according to recommended best practices. Some high level checks are even performed on the Operating System level.
  • Reports all settings that differ from the default settings.
  • Reports recent changes in the instance of SQL Server.

    On a broader level, the tool verifies the above mentioned based on rules divided into the following categories:

    1. Security rules
    2. Database Engine rules
    3. Analysis Services rules
    4. Replication rules
    5. Integration Services rules

    For example, if you applied the initial release version of SQL Server 2005 SP2, existing SQL Server 2005 maintenance plans and SSIS packages that contain cleanup tasks might run those tasks at shorter intervals. The tool if it scans your SQL Server instance and finds out if you are on a build lower than the one mentioned in KB933508, then it would provide the recommendation to apply the fix.

    The SQL BPA UI can be used to run scans on remote machines also. So, there is no need to install the tool on the SQL Server box which you want to scan. You can also configure the type of scan you want the SQL BPA tool to perform on your server.

    Microsoft PSS also has the capability to include this tool as a part of the PSSDIAG collection that they send out to collect diagnostic data from the instance based on the need to collect BPA analytics data.

    For a more detailed information about the above mentioned points, you can always refer the SQL Server Best Practices Analyzer Help chm file.

  • Best Practices Analyzer

    I have seen a lot of people asking "Are we following best practices for our SQL Servers?". The Best Practice Analyzer can try and guide you along a path which would lead to the right answer. A simple answer is not possible because of the following reasons:
    1. We are not conversant with your environment and setup
    2. We do not know what kind of business implementation this SQL Sever is
    3. We do not know what constraints are present which prevents some of the best practices from being followed
    4. We do not know which data/databases are critical/non-critical etc. and also do not know what kind of SLAs need to be met.

    Even then, an attempt is made using the Best Practice Analyzer to verify if common best practices are being implemented across your SQL Server. It creates a repository on the our server and stores the analysis for the server in the database which can be used at a later date.
    The SQL Server 2005 Best Practices Analyzer (BPA) gathers data from Microsoft Windows and SQL Server configuration settings. BPA uses a predefined list of SQL Server 2005 recommendations and best practices to determine if there are potential issues in the database environment.

    This tool is available at:
    For SQL Server 2000
    http://www.microsoft.com/downloads/details.aspx?familyid=B352EB1F-D3CA-44EE-893E-9E07339C1F22&displaylang=en
    For SQL Server 2005
    http://www.microsoft.com/downloads/details.aspx?FamilyId=DA0531E4-E94C-4991-82FA-F0E3FBD05E63&displaylang=en

    Reorganize data and index pages

    There are a few ways that this can be achieved:

    1. Shrinking the database files (data file or transaction log file)

    2. DBCC DBREINDEX (Similar to dropping and re-creating the indexes)

    3. DBBC INDEXDEFRAG (De-fragmenting the indexed pages to remove logical scan fragmentation)

    Note: It needs to be kept in mind that DBREINDEX is a fully-logged operation and can cause the transaction log to grow by large amounts when the database size is considerably large. So there have been situations when the transaction log has grown out of proportion and filled up the entire disk. If the T-log does grow out of proportion and you do choose to truncate/shrink the file, then please do so after verifying the points below:

    1. Transactional replication is not configured for the database

    2. Log shipping is not configured for the database

    3. Database mirroring is not configured for the database (For SQL 2005 SP1 and above)

    4. Any other operations are not being performed which need transactional log consistency in terms of LSN chains

    Online re-indexing is a feature which is available in SQL Server 2005 Enterprise Edition only. Please note that rebuilding the indexes would cause the statistics associated with those indexes to also be updated. This however would not update the AUTO CREATED statistics.

    The following articles could be useful:

    SET OPTION considerations when running DBCC with indexes on computed columns

    http://support.microsoft.com/kb/301292/

    DBCC DBREINDEX

    http://msdn2.microsoft.com/en-us/library/ms181671.aspx

    The DBCC SHOWCONTIG output for SQL Server 2000 and 2005 will help you find out the current status of fragmentation for the database. A sample output would look like this:

    DBCC SHOWCONTIG scanning ‘Customers’ table…

    Table: ‘Customers’ (2073058421); index ID: 1, database ID: 6

    TABLE level scan performed.

    – Pages Scanned…………………………..: 3

    – Extents Scanned…………………………: 2

    – Extent Switches…………………………: 1

    – Avg. Pages per Extent……………………: 1.5

    – Scan Density [Best Count:Actual Count]…….: 50.00% [1:2]

    – Logical Scan Fragmentation ………………: 0.00%

    – Extent Scan Fragmentation ……………….: 50.00%

    – Avg. Bytes Free per Page…………………: 246.7

    – Avg. Page Density (full)…………………: 96.95%

    The logical scan fragmentation should ideally be below 20% but anything above 40% would mean an INDEXDEFRAG or DBREINDEX is required. The script which is from the same MSDN article can help you run an INDEXDEFRAG or DBREINDEX based on the logical scan fragmentation count.

    A sample script for the same can be found under the topic of "DBCC SHOWCONTIG" in SQL Server Books Online (2000 and 2005)

    In SQL Server 2005, the following features may be helpful to you while using the ALTER INDEX command:

    REBUILD [ WITH ( [ ,… n]) ]

    Specifies the index will be rebuilt using the same columns, index type, uniqueness attribute, and sort order. This clause is equivalent to DBCC DBREINDEX. REBUILD enables a disabled index. Rebuilding a clustered index does not rebuild associated nonclustered indexes unless the keyword ALL is specified. If index options are not specified, the existing index option values stored in sys.indexes are applied. For any index option whose value is not stored in sys.indexes, the default indicated in the argument definition of the option applies.

    The options ONLINE and IGNORE_DUP_KEY are not valid when you rebuild an XML index.

    If ALL is specified and the underlying table is a heap, the rebuild operation has no affect on the table. Any nonclustered indexes associated with the table are rebuilt.

    The rebuild operation can be minimally logged if the database recovery model is set to either bulk-logged or simple.

    WITH ( LOB_COMPACTION = { ON OFF } )

    Specifies that all pages that contain large object (LOB) data are compacted. The LOB data types are image, text, ntext, varchar(max), nvarchar(max), varbinary(max), and xml. Compacting this data can improve disk space use. The default is ON.

    ON

    All pages that contain large object data are compacted.Reorganizing a specified clustered index compacts all LOB columns that are contained in the clustered index. Reorganizing a nonclustered index compacts all LOB columns that are nonkey (included) columns in the index. For more information, see Creating Indexes with Included Columns. When ALL is specified, all indexes that are associated with the specified table or view are reorganized, and all LOB columns that are associated with the clustered index, underlying table, or nonclustered index with included columns are compacted. OFF Pages that contain large object data are not compacted.

    OFF

    has no affect on a heap.The LOB_COMPACTION clause is ignored if LOB columns are not present.

    REORGANIZE

    Specifies the index leaf level will be reorganized. This clause is equivalent to DBCC INDEXDEFRAG. ALTER INDEX REORGANIZE statement is always performed online. This means long-term blocking table locks are not held and queries or updates to the underlying table can continue during the ALTER INDEX REORGANIZE transaction. REORGANIZE cannot be specified for a disabled index or an index with ALLOW_PAGE_LOCKS set to OFF.

    Furthermore, the dynamic management view sys.dm_db_index_physical_stats would help you get statistical information pertaining to indexes on SQL Server 2005. The columns mentioned below in this DMV output could be helpful in analyzing the need for index reorganization.

    avg_fragmentation_in_percent: Logical fragmentation for indexes, or extent fragmentation for heaps in the IN_ROW_DATA allocation unit. The value is measured as a percentage and takes into account multiple files. For definitions of logical and extent fragmentation, see Remarks. 0 for LOB_DATA and ROW_OVERFLOW_DATA allocation units.NULL for heaps when mode = SAMPLED.

    fragment_count: Number of fragments in the leaf level of an IN_ROW_DATA allocation unit. For more information about fragments, see Remarks.NULL for nonleaf levels of an index, and LOB_DATA or ROW_OVERFLOW_DATA allocation units. NULL for heaps when mode = SAMPLED.

    avg_fragment_size_in_pages: Average number of pages in one fragment in the leaf level of an IN_ROW_DATA allocation unit. NULL for nonleaf levels of an index, and LOB_DATA or ROW_OVERFLOW_DATA allocation units. NULL for heaps when mode = SAMPLED.

    The following article could be helpful:Microsoft SQL Server 2000 Index Defragmentation Best Practices

    http://www.microsoft.com/technet/prodtechnol/sql/2000/maintain/ss2kidbp.mspx