Db2 Log Space Utilization Test

DB2 UDB database writes log files called transaction log to record all changes to application data in the database. During transactions, modifications to the database by each transaction is serially recorded in the transaction log. Using this information, the DBA can track which transaction made which changes to DB2 UDB Server data. Mainly, Db2 uses transaction logs to restore previosly committed changes and to undo the changes that were not committed when performing crash or roll forward recovery. Lack of adequate space in the transaction log would have serious repercussions on the way the DB2 UDB server carries out database updations; sometimes, critical changes to the database could get lost due to a space crunch. The Db2 Log Space Utilization test enables administrators to constantly track the space consumption by the transaction log, so that administrators are instantly notified of inadequacies, and are prompted to act fast.

Target of the test : A DB2 database server

Agent deploying the test : An internal agent

Outputs of the test : One set of results for every database instance on the DB2 database server that is currently active

Configurable parameters for the test
Parameter Description

Test period

How often should the test be executed

Host

The IP address of the DB2 server

Port
  • The port number through which the DB2 server communicates. The default port is 50000.
    		•

    User

    Specify the name of the user who is authorized to access the target database server and collect the required metrics in this text box. You can create a separate user on the OS hosting the DB2 server for this purpose. The steps for the same are detailed in the Creating a Special User for Monitoring DB2 Server topic.

    Password

    Enter the password of the specified USER in the PASSWORD text box.

    Confirm Password

    Confirm the Password by retyping it in the Confirm Password text box.

    Database

    Specify the name of the database on the monitored DB2 server to be used by this test.

    Include DB

    Specify a comma-separated list of databases that you wish to monitor in the Include DB text box.

    Exclude DB

    Specify a comma-separated list of databases that need to be excluded from monitoring in the Exclude DB text box.

    SSL

    If the target database server is SSL-enabled, then set the SSL flag to Yes. If not, then set the SSL flag to No.

    Trust Store File Name

    This parameter is applicable only if the target DB2 UDB database is SSL-enabled, if not, set this parameter to none. Specify the file name of the client-side SSL truststore that contains the server certificate required for establishing an SSL connection. The truststore is used to verify the identity of the server and enable a secure communication channel.

    By default, the truststore file should be placed in:<EG_INSTALL_DIR>/jre/lib/security/mytruststore.jks

    Here, mytruststore.jks is the Truststore file name. You may change this to any valid file name. By default, none is specified against this text box.

    Trust Store Password

    This parameter is applicable only if the target DB2 UDB database is SSL-enabled, if not, set this parameter to none. If a Truststore File name is provided, then, in this text box, provide the password that is used to obtain the associated certificate details from the Truststore File. By default, this parameter is set to none.

    Confirm Password

    Confirm the Password by retyping it in the Confirm Password text box.
    Measures made by the test:
    Measurement Description Measurement Unit Interpretation

    Maximum log used

    Indicates the amount of maximum log space that is currently being used.

    GB

    If the value of this measure keeps growing, it indicates that the log is growing rapidly and may soon run out of space! In such cases, you should clear the transaction log to ensure that there is adequate space to log subsequent transactions.

    Currently used space

    Indicates the amount of transaction log space that is currently in use.

    GB

    Ideally, this value should be low. A high value for this measure requires immediate attention, as it indicates that the transaction log is suffering from severe space constraints. There is hence the danger of subsequent database modifications going unrecorded. Typically, excessive space usage can be attributed to too many changes been written to the log, but very little/none to the database. Further diagnosis can alone reveal the root-cause of this deviant behavior.

    Total free space

    Indicates the amount of log space that is currently available for use in this database.

    GB

    Ideally, the value of this measure should be high.

    Used percentage

    Indicates the percentage of transaction log space that is currently in use.

    Percent

    The value of this measure is calculated using the following formula:

    Used Percentage = Currently used space/ Maximum log used.