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6. Monitoring SQL Server Performance
• Objectives
– Monitoring Resource Usage
• Contents
– Developing a Performance Monitoring
Methodology
– Choosing Among Monitoring Tools
– Performing Monitoring Tasks
• Practicals
– Monitor your SQL server system
• Summary
Developing a Performance Monitoring Methodology
• Establish appropriate and effective monitoring goals
• Determine which activities and resources to monitor
• Develop a long-term monitoring strategy
• Establishing Monitoring Goals
• Before you begin monitoring SQL Server 2000 performance, you should
determine your monitoring goals
• User perspective
– To minimize the response time for each query submitted by each user
• Server perspective
– To maximize the total server throughput of queries submitted by users
Identifying Performance Bottlenecks
•
Inadequate hardware resources, such as memory or processor, are
common causes of bottlenecks.
•
Low gauge meter numbers can mean that the system is performing better
than expected, but they can also reveal a performance bottleneck. Usally
beyond the server hardware. Can be network or software bottlenecks.
•
Some bottlenecks can be solved by adding additional hardware resources
or by moving some of the load to other servers.
•
Solving one performance bottleneck can reveal another performance
bottleneck.
•
You might need to optimize queries that were efficient with fewer users
and plenty of hardware capacity as database utilization changes
Determine Trends
• When monitoring SQL Server 2000, you must gain an understanding of the
normal range of values for various counters.
• You should establish an evolving performance baseline.
• This involves recording an initial performance baseline using a number of
different monitoring tools.
• This will help you understand how various aspects of your system perform
under normal production loads
Determining Resources and Activities to Monitor
• Hardware resources might be
inadequate for the load on the
server
• Competing server applications on
the SQL Server 2000 computer
might be using excessive
resources
• Hardware resource use might be
unbalanced
• A hardware resource might be
malfunctioning
• General network congestion might
occur
• Improper use of cursors or ad hoc
queries
• Poor database design
• Poorly written applications
Choosing Among Monitoring Tools
• Using System Monitor
– Windows 2000 System Monitor is used to monitor resource usage on either the
local computer or a remote computer
• Using Task Manager
– Task Manager is used to provide a snapshot in real time
• Using SQL Profiler
– SQL Profiler is a graphical SQL Server 2000 tool used to monitor (trace) selected
SQL Server events
• Using the SQL Server Enterprise Manager Current Activity Window
– The SQL Server Enterprise Manager Current Activity window displays a
snapshot of information regarding processes, user activity, locks held by
processes, and locks held on objects
• Using SQL Query Analyzer
– The system stored procedures you can use to monitor SQL Server 2000 activity
and performance
• Using SNMP
– SNMP can only monitor the default instance.
– SQL Server 2000 support for SNMP is enabled automatically
Performance Objects for Tracking
Using System Monitor
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SQL Server: Access Methods
– Index and query efficiency based on types of pages accessed
SQL Server: Backup Device
– Throughput or progress of backup and restore
SQL Server: Buffer Manager
– Lack of physical memory
SQL Server: Cache Manager
– Efficiency of plan caching and reuse
SQL Server: Databases
– Level of user activity in a database
SQL Server: General Statistics
–
Overall connection activity
SQL Server: Latches
– Performance length of waits for internal resource
SQL Server: Locks
– Overall number and types of locks
SQL Server: Memory Manager
– Overall memory usage
SQL Server: SQL Statistics
– Query compilation speed
SQL Server: User Settable Object
Event Categories That Can Be Monitored
Using SQL Profiler
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Cursors
– The actual types of cursors being used
Database
– Automatic growth of data and transaction log files
Errors and Warnings
Locks
Objects
– creation of objects by applications and users
Performance
– Query execution and query optimizer efficiency
Scans
– Types of scans being performed on an object. (tables/indexes)
Security audit
Server
– Changes in SQL Server memory usage
Sessions
– Connected users, database activity
Stored procedures
– to determine additional memory needs
Transactions
TSQL
Using SQL Query analyzer
•
Sp_who
– Active users and their processes
•
Sp_who2
– Active users and their processes, more readable.
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Sp_lock
– Blocking locks and deadlocks, and the process causing them.
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sp_spaceused
– Database or object space usage.
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Sp_monitor
– Volume of work performed during period of time.
Task Manager
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Monitoring Resource momentary Usage
View these columns
Task Manager
• Monitoring Resource momentary Usage
System to left has enough memory, system to right need
more physical memory
System Monitor, analysis
Object
Counter
Recomended value
Measures
Processor
%cpu time
<70%
Time spent working
Memory
Pages/sec
<5
Ram to disk and reverse
Memory
Available
>4MBhyte
Non allocated memory.
Memory
Commited
< physical ram
Amount of ram commited
Physical
Disk
Disk queue <2
Waiting to be written
% Disk time <50%
Disk busy
Network use <30%
Network bandwith used
Disk
Network
Segment
Monitoring with Windows System Monitor
1. Log in to Windows as Administrator.
2. From the Start menu, select Programs -> Administrative Tools ->
Performance.
3. Click the + icon on the toolbar to start adding counters to the chart.
Monitoring, adding some counters
4. In the Performance Object drop-down list, select Processor (not Process).
5. In the counter list box, select % Processor Time and click Add.
6. In the Performance Object drop-down list, select Memory.
7. In the Counter list box, select Pages/Sec and click Add.
8. Click Close and notice the graph being created on the screen.
Monitoring, highligting & alerts
9. Press Ctrl+H and notice the current counter turn white. This makes the
chart easier to read.
10. In the left pane, under Performance Logs and Alerts, select Alerts.
11. From the Action menu, select New Alert Settings.
12. Enter Test Alert in the Name box and click OK.
Monitoring, making alert on processor
13. In the Comment box on the General tab
of the Test Alert property sheet, type
Processor Alert.
14. Click Add, select Processor in the
Performance Object drop-down list and
% Processor Time in the Counter list
box, click Add, then click Close.
15. Back in the Test Alert property sheet
select Alert When the Value Is Under
and set the value to 100. This will
generate an alert if the processor is not
busy 100 percent of the time. In the
real world, this would be set to Over
70 percent, thus warning you just
before it becomes a serious problem.
Monitoring, making alert on processor
16. On the Action tab, check the Send a
Network Message To box and enter
your machine name in the text box
below.
17. Click OK to start the alert and watch the
alerts generated for a short time. Then
right-click the alert and select Stop to
stop the alert from firing.
18. Exit Windows System Monitor.
From now on, alerts would be sent to server
and logs would be written.
This when processor time is under 70 %,
this is just testing, in real life OVER
would make sense
Logging with Windows System Monitor
1. Open Windows System Monitor from
the Administrative Tools folder on the
Start menu.
2. In the left pane, select Counter Logs.
3. From the Action menu, select New
Log Settings and when the New Log
Settings dialog box appears, name
the new log Test Log, then click OK.
4. On the General tab of the Test Log
property sheet, under the Counters
box, click Add.
5. In the Performance Object drop-down
list, select Processor (not Process).
6. In the Counter list box, select %
Processor Time and click Add.
7. In the Performance Object drop-down
list, select Memory.
8. In the Counter list box, select
Pages/Sec and click Add.
Logging with Windows System Monitor
9. Click Close to return to the Test Log
dialog box.
10. On the Log Files tab, notice the
location and name of the files that will
be created and click OK to start the
log
11. Allow the log to run for about five
minutes to gather some data.
12. Right-click the Test Log and select
Stop to stop the log so that you can
read from it.
13.In the left pane, click System Monitor.
14. Now right-click in the gray area of the
chart and select Properties.
15. On the Source tab, click Log File.
Logging with Windows System Monitor
16. Click Browse, select the log file
created in step 10, and click OK.
17. Click the + icon on the toolbar to
add objects to the graph.
18. In the Add Counters dialog box, in
the Performance Object dropdown list, select Processor (not
Process).
19. In the Counter list box, select %
Processor Time and click Add.
20. In the Performance Object dropdown list, select Memory.
21. In the Counter list box, select
Pages/Sec and click Add.
22. Click close and notice that the
recorded data now appears in the
graph.
23. Close Windows System monitor
Monitoring Current Locking and User Activity
Monitoring Current Locking and User Activity
• Process information, right click
on process and select
properties.
• Locks and Processes ID
Monitoring Current Locking and User Activity
• Process information,
• Locks and Processes ID
• right click on process and select
properties. You can see latest
SQL message caused process
Using Query Analyzer, check your expressions
1. From the Start menu, choose
Programs -> Microsoft SQL
Server -> Query Analyzer.
2. When asked to log in, use
Windows Authentication. You will
see the query window.
3. From the Query menu, select
Current Connection Properties.
4. In the property sheet, check Set
Statistics Time and Set Statistics
IO. Set Statistics Time displays
CPU time used, while Set
Statistics IO displays disk time.
Using Query Analyzer, check your expressions
5. From the Query menu, select Show
Execution Plan to see a graphic
representation of how SQL Server
executes your query.
6. On the query window toolbar, select
Northwind in the DB list box to set
Northwind as the default database.
7. In the query window, type the following
query:
8. USE Northwind
SELECT * FROM employees
9. Click the Messages tab (at the bottom
of the screen) and notice the
execution, parse, and compile times;
then click the Execution Plan tab.
10. In the Execution Plan pane, hold your
mouse pointer over each icon in turn;
notice that they come with ToolTips to
help you better understand each step
of execution.
Monitoring with SQL Profiler
1. From the Start menu, choose
Programs -> SQL Server -> Profiler.
2. From the File menu, choose New, and
then click Trace to bring up the Trace
property sheet. You will be asked to
log in at this point; do so with either
form of authentication.
3. In the Trace Name box, type Monitor.
4. There are several templates to choose
from in the templates drop-down list
box. Each of them gives you a preset
trace definition to work with. Leave
the template name as
SQLProfilerStandard.
5. Check the Save to File check box and
click Save in the Save As dialog box
to accept the default name and
location.
6. Check the Save to Table check box, log
in to the server again, and in the
Destination Table dialog box fill in the
following:
–
–
Database: Northwind
Table: Monitor
7. Click OK to return to the Trace property
sheet.
Monitoring with SQL Profiler
7. Click the Events tab.
8. Under Available Event Classes,
select Objects and click Add. This
will monitor the opening and
closing of objects such as tables.
9. Click the Data Columns tab to
change the data you see in the
trace.
10. Under Unselected Data, select
End Time and click Add.
11. Click Run to start the trace.
Monitoring with SQL Profiler
12. Leave Profiler running and open Query Analyzer; log in using Windows
Authentication.
13. Execute the following query:
14. USE Northwind
SELECT * FROM products
15. Switch back to Profiler and click the Pause button (double blue lines).
Notice the data that was collected by the trace.
Using the Index Tuning Wizard
1. Open Profiler.
2. From the Tools menu, select Index
Tuning Wizard. This will open the
Welcome screen.
3. Click Next and log in.
4. On the Select Server and
Database screen, select
Northwind as the database to
tune.
5. Check Keep All Existing Indexes.
6. Check Thorough as the analysis
type and click Next.
Using the Index Tuning Wizard
7. In the Specify Workload screen,
click the My Workload File button.
8. In the File Open dialog box, select
the Monitor trace (created earlier)
and click OK to return to the
Specify Workload screen, where
you will see the Monitor file listed
under My Workload File.
9. Click the Advanced Options button,
note the defaults, and click OK.
10. Click Next.
11. In the Select Tables to Tune
screen, click Select All Tables.
Using the Index Tuning Wizard
12. Click Next, and the wizard will
start examining your indexes.
13. After SQL Server has finished
examining your queries it displays
a list of recommended indexes for
you to create. Browse this list and
click Next.
14. On the final screen, click Finish to
end the wizard.
15. When you receive a message
stating that the wizard has
completed, click OK.
16. Exit Profiler.
Optimizing Techniques
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Queries and Stored Procedures
The first thing to ask yourself when you are getting slow response times is whether you could
be using a stored procedure here instead of a client-side query.
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Tempdb
Tempdb should be between 25 and 40 percent of the size of your largest database
Is your Tempdb big enough to handle the load that your queries put on it? Think of Tempdb
as a scratchpad for SQL Server; when queries are performed, SQL Server uses this
scratchpad to make notes about the result set
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Query Governor
Controlled by the Query Governor Cost Limit setting. This setting tells SQL Server not to run
queries longer than x. Limit is set to 2, any query that is estimated to take longer than two
seconds would not be allowed to run
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Max Async I/O
The maximum number of asynchronous input/output (Max Async I/O) threads by default in
SQL Server is 32. That means that SQL Server can have 32 outstanding read and 32
outstanding write requests at a time
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LazyWriter
LazyWriter is a SQL Server process that moves information from the data cache in memory
to a file on disk. Average Disk Queue Windows System Monitor counter and verify that it
is not more than 2 per physical disk