Shulou(Shulou.com)06/01 Report--

Online system administrators should monitor certain parts of the online system on a regular basis. This is very important in the initial configuration and in the parameter adjustment phase after running. The monitoring system mainly monitors the following aspects:

1. Message log

two。 Shared memory usage

Status and use of 3.chunk

4. Problematic user activity: sql statements, locks, clues.

5. Resource restriction

1.1. The message log stores diagnostic and administrative information about the state of the online system.

Location: $INFORMIXDIR/tmp/online.log

The last 20 message file records can be displayed through the onstat-m command, and only the informix user has permission to view the file.

Use the cat / dev/null > onlin.log command to periodically empty the files.

2.1. Because shared memory can be allocated dynamically by the online system, you should monitor the number and size of segments that have been created.

Monitor memory segments by using the command onstat-g seg command

The memory segment is counted into the virtual part through onmode-a segsize.

Monitor the allocation of shared memory through the onstat-g mem command

Release shared memory segments that are no longer in use by using the command onmode-F.

3. Monitor the use of chunk

View the status of chunk through the command onstat-d command

The main concern is whether the chunk in dbspace is full and whether chunk is offline.

4. Monitor user activity

4.1.online system administrators can monitor the session activity of individual users, and from this information, you can determine whether there are some problems in the application code, and it is up to the developer to determine where the problem lies.

4.2. Activities below the user quota need to be monitored.

The reading and writing of each user.

The number and type of locks held.

The last sql statement.

The clues assigned by each user.

A temporary table created by the user.

The long transaction of the user.

Information about the session can be obtained through the command onstat-g ses.

Further information about a session can be obtained through the command onstat-g ses session-id.

4.3.sql information

Information about sql can be obtained by using the command onstat-g sql

Further, information about a session can be obtained through onstat-g sql session-id.

4.4. Monitor user leads

You can list all the clues that require the rsam task control block structure with the command onstat-u.

4.5. Monitor transaction length

The size of the logical log space used by a session can be obtained from the syssesprof table of SMI or by the command onstat-g tpf session-id. It is important to note, however, that syssesprof records exist only when the client is connected.

4.6. Cancel a problematic session

Onmode-z session-id

In some cases, it may be necessary to end a session, such as a deadlock, a long transaction, or a user holding a requested resource. In this case, you should take the initiative to exit the application if possible.

If not, you can kill the application. The session will detect a broken connection to the client process. If the session is still running, you can run the onmode-z command with the session id.

It is important to note that you do not use the kill command on the unix system to clear the session.

5.1. Resource restriction

In many cases, the initial configuration of online system resources can not meet the various requirements of the system. Online system administrators can use the onstat-p command to monitor whether sufficient resources are available.

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