Server and Client Configuration and Troubleshooting
- Chapter 3: Server and Client Configuration and Troubleshooting
- Configuring SQL Server
- Setting Up and Configuring Remote and Linked Servers
- Windows NT and SQL Server
- Troubleshooting Server Problems
- Client Configuration
- Troubleshooting Connectivity Problems
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Chapter 3: Server and Client Configuration and Troubleshooting
With previous versions of SQL Server, as soon as it was installed, the DBA sat down to configure it. SQL Server 7.0's capability to configure itself removes much of that need. However, you may find some things useful in solving problems specific to your installation. This Appendix Covers the startup of SQL Server. Then, it looks at some of the configuration options that you may want to explore. Note that the most useful configuration options relate to how SQL Server performs. This Appendix Also covers SQL Server's interaction with Windows NT. The server-side discussion ends with a section on server troubleshooting. The discussion then turns to the client side, and covers client setup and configuration. Finally, because one of the most annoying tasks you will face as a SQL Server DBA involves dealing with connectivity problems, this chapter shows you a few tricks for dealing with this troublesome part of SQL Server.
Starting, Pausing, and Stopping SQL Server
When you installed SQL Server, you most likely checked the option to have SQL Server and the SQL Agent start when Windows NT starts. On some occasions, however, you may want to stop and start the server without taking down NT. You can do this with Enterprise Manager, or with the SQL Service Manager. I almost always use the Service Manager because it comes up quickly, and its traffic light icon is easily accessible from my Icon Tray. But there are other ways of stopping and starting the server, including the following:
The Services applet in Control Panel
From the command prompt
Starting SQL Server
You can start SQL Server from the command prompt in two different ways:
NET START mssqlserver
sqlservr
NET START starts SQL Server as a service just as Enterprise Manager, SQL Service Manager, or Control Panel do. When SQL Server is running as a service, you can log off NT and the server continues to run. If you start it by just typing sqlservr at the command prompt, however, it is not run as a service. This means that you must shut it down (by pressing Ctrl+C) before you log off of NT. Note that you shouldn't minimize the command window. When you start SQL Server this way, it runs as a foreground application. If you minimize the window, NT pages all the SQL Server memory out. You can specify some options on the command line; some of the most useful ones are discussed later in this chapter.
You can also start SQL Server from DMO with the Start method of a server object. The Start method has four parameters, as shown here.
|
Parameter |
Description |
|
StartMode |
When set to true, an attempt is made to connect on successful start. When set to false, no attempt is made to connect after a successful start. |
|
Server |
This parameter is optional and is a string that specifies the SQL Server name. You can also provide the server name in the Name property of the SQL Server object. |
|
Logon |
This parameter is optional, and is a string specifying the SQL Server logon that will be used to connect after the server is started. (StartMode is true.) |
|
Password |
This parameter is optional and is a string specifying the SQL Server password that will be used to connect after the server is started. (StartMode is true.) |
Pausing SQL Server
You can pause SQL Server with Enterprise Manager, SQL Service Manager, the Services applet in Control Panel, the command line, or DMO. You can pause the server only when it is running as a service. When you pause SQL Server, no new connections are allowed, but existing connections are allowed to complete their work. You should pause the SQL Server and broadcast a "Server going down in x minutes" message when you plan to take the server down. In Enterprise Manager, SQL Service Manager, and Control Panel, it is just a matter of clicking the Pause button. From the command line, just type the following:
NET PAUSE MSSQLSERVER
In DMO, use the Pause method of a SQL Server object. This method has no arguments.
You can restart a paused server with the Start/Continue button in SQL Service Manager, the Continue button in the Services applet, or the Continue choice in Enterprise Manager. To restart from the command line, use the following:
NET CONTINUE MSSQLSERVER
In DMO, use the Continue method of a SQL Server object. The method has no arguments.
General Tip
There doesn't seem to be any way to pause and resume SQL Server with Transact-SQL.
Stopping SQL Server
When you stop the SQL Server, SQL Server disallows new connections and allows existing connections to finish their work. Then, it takes a checkpoint in every database, and shuts down. It's possible to stop SQL Server with Enterprise Manager, Service Manager, the Services applet, the command line, DMO, and Transact-SQL. In the graphical tools, just click Stop. To stop SQL Server from the command line, use the following:
NET STOP MSSQLSERVER
General Tip
Note that if you don't start SQL Server as a service, you must use Ctrl+C to stop it.
In DMO, just use the Stop method of the SQL Server object. This method has no arguments.
In Transact-SQL you can issue the following shutdown command:
SHUTDOWN [WITH NOWAIT]
If you don't specify WITH NOWAIT, SQL Server stops in the same fashion described previously. If you specify WITH NOWAIT, existing connections are stopped, their transactions are rolled back, and no checkpoints are taken. You should use the NOWAIT option only in an emergency and when you are certain that the server needs to stop immediately.
Startup Switches
Some startup switches are used when SQL Server starts. The default values are stored in the Registry. Any switches you provide on the command line override the Registry values. The following three switches are required.
|
Switch |
Description |
|
-dmaster_file_path |
The fully qualified name of the master database file (for example, C:\MSSQL7\DATA\MASTER.MDF) |
|
-lmaster_log_path |
The fully qualified name of the transaction log for the master database (for example, C:\MSSQL7\DATA\MASTER.LDF) |
|
-eerror_log_path |
The fully qualified name of the SQL Server Error log file (for example, C:\MSSQL7\LOG\ERRORLOG) |
You can change the default values for startup switches in several ways. In Enterprise Manager, highlight the server, right-click, and choose Properties. On the General tab, click the Startup Parameters button. Or you can edit the Registry, although I don't recommend doing that. The startup parameters are stored in the following: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSSQLServer\MSSQLServer\Parameters
The parameters are named SQLArg0, SQLArg1, SQLArg2, and so on. The order doesn't matter because the switch is part of the parameter.
You can also use the following useful switches at startup.
|
Switch |
Description |
|
-c |
Starts SQL Server so that it does not run as a service. This shortens startup time, but there is no other advantage. When you start SQL Server this way, you cannot log off of NT without stopping SQL Server first. |
|
-f |
Starts SQL Server with a Minimal configuration. This is useful for recovering from a failed configuration. |
|
-m |
Starts SQL Server in single-user mode, and enables the Allow Updates to System Tables option (discussed later). This option is most often used when restoring master (see Chapter 6, "Backup and Recovery," for more information). |
|
-pprecision_level |
Specifies the maximum level of precision used for decimal and numeric datatypes. The actual precision allowed is 38; but by default, SQL Server only allows 28. If you need the additional 10 digits, use this startup switch. |
|
-sregistry_key |
Starts SQL Server with a set of parameters stored under the key named in registry_key. You can only use this option from the command line, but it enables you to have many previously defined startup options. |
|
/Ttrace_flag# |
Specifies that the server should start with a trace flag. |
|
-x |
Turns off the recording of CPU and cache-hit ratio statistics. This can improve performance, but you will not be able to see these values in Performance Monitor. It may also interfere with Performance Condition alerts (see Chapter 8, "Jobs and Alerts," for more information on alerts). |
When I'm going to use a switch once—for example, putting the server in single-user mode so that I can restore the master database—I set the switch with Control Panel. To do this, use the Services applet. Highlight the MSSQLServer service. You will see the display shown in Figure 3.1.
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Figure 3.1 Specifying startup switches in Control Panel.
You can just type the –m switch (or another switch name) in the Startup Parameters box at the bottom of the screen. It applies for a single startup of SQL Server. I think this is much easier than going through Enterprise Manager to change the parameters, and then having to remember to change them back.
General Tip
There's no way to specify startup switches when you start the server with DMO. It uses the default settings from the Registry.
Setting the Polling Interval
Both Enterprise Manager and SQL Service Manager routinely poll the SQL Server to determine whether it (as well as SQL Server Agent, MSDTC, and Full-Text Search) is still running. If you look closely at the Service Manager icon at the bottom right of your screen, you will periodically see a little red "blip" when this polling happens. You can control the polling interval. In Enterprise Manager, highlight a server and choose Tools, Options. Choose the target service and specify the polling interval in seconds. If you uncheck the Poll Server box, Enterprise Manager will not poll. The only downside of this is that you won't see little red, green, and yellow indicators of server state in the console tree. The upside of not polling is that there's less demand on the server.
To specify SQL Service Manager's polling interval, open Service Manager and select the service. Then right-click the icon in the System Tray and choose Options. Enter the polling interval in seconds.
General Tip
There's no relationship between Service Manager's polling interval and Enterprise Manager's. They're both client programs operating independently.