2.0.1 DB2 Query Workload Test

Nothing can degrade the performance of the server like a resource-hungry or a long-running query! When such queries execute on the server, they either hog almost all the available CPU, memory, and disk resources or keep the resources locked for long time periods, thus leaving little to no resources for carrying out other critical database operations. This can significantly slowdown the database server and adversely impact user experience with the server. To ensure peak performance of the DB2 UDB server at all times, such queries should be rapidly identified and quickly optimized to minimize resource usage. This is where the DB2 Query Workload test helps.

At configured intervals, this test compares the usage levels and execution times of all queries that started running on the server in the last measurement period and identifies a ‘top query’ in each of the following categories - CPU usage, memory usage, disk activity, and execution time. The test then reports the resource usage and execution time of the top queries and promptly alerts administrators if any query consumes more resources or takes more time to execute than it should. In such a scenario, administrators can use the detailed diagnosis of this test to view the inefficient queries and proceed to optimize them to enhance server performance.

Target of the test : A DB2 UDB server

Agent deploying the test : An internal agent

Outputs of the test : One set of results for each database instance on the DB2 UDB server monitored

Configurable parameters for the test
Parameter Description

Test Period

How often should the test be executed.

Host

Specify the IP address of the DB2 server in this text box.

Port

Specify the port at which the target host is listening. The default port is 50000.

Username, Password and Confirm Password

For the eG agent to collect the required metrics from the target database server, the eG agent should be configured with the credentials of a user who has SELECT privilege on the MON_CURRENT_SQL administrative view. The MON_CURRENT_SQL administrative view returns key metrics that can be used to identify long running activities (activities that were submitted on all members of the database and have not yet been completed). To create such a user issue the following command at the DB2 prompt:

CONNECT TO <dbname> USER <username> USING <password> grant select on SYSIBMADM.mon_current_sql to <username>;

For example:

CONNECT TO ProdDB USER eGMonitoring USING p@ssword123 grant select on SYSIBMADM.mon_current_sql to eGMonitoring;

Here,

ProdDB indicates the database name;

eGMonitor indicates the username;

p@ssword123 indicates the password of mentioned user;

Specify the name of such a user in User tex t box.

In the Password text box, specify the password of the user.

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

Database

The test uses a database on the monitored Db2 UDB server. Specify the name of the database in the Database 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.

DDCount

By default, the detailed diagnosis of this test, if enabled, will report only the top-5 records. This is why, the DDCount parameter is set to 5 by default. If you want to include more or less records in detailed diagnosis, then change the value of this parameter accordingly.

Detailed Diagnosis

To make diagnosis more efficient and accurate, the eG Enterprise embeds an optional detailed diagnostic capability. With this capability, the eG agents can be configured to run detailed, more elaborate tests as and when specific problems are detected. To enable the detailed diagnosis capability of this test for a particular server, choose the On option. To disable the capability, click on the Off option.

The option to selectively enable/disable the detailed diagnosis capability will be available only if the following conditions are fulfilled:

  • The eG manager license should allow the detailed diagnosis capability
  • Both the normal and abnormal frequencies configured for the detailed diagnosis measures should not be 0.
Measurements made by the test
Measurement Description Measurement Unit Interpretation

Maximum physical reads

Indicates the number of physical disk reads performed by the top query per execution.

Number

If the value of this measure is abnormally high, you can use the detailed diagnosis of this measure to view the top-5 (by default) queries generating maximum physical disk activity. From this, you can identify the top query in terms of number of physical disk reads. You may then want to optimize the query to reduce the disk reads.

Maximum physical writes

Indicates the number of memory buffers used by the top query per execution.

Number

If the value of this measure is abnormally high, you can use the detailed diagnosis of this measure to view the top-5 (by default) queries consuming memory excessively. From this, you can easily pick that query which is consuming the maximum memory. You may then want to optimize the query to minimize memory usage.

Maximum CPU time

Indicates the CPU time used for processing upon execution of the top query.

Seconds

If the value of this measure is abnormally high, you can use the detailed diagnosis of this measure to the top-5 (by default) queries hogging the CPU resources. From this, you can easily pick that query which is consuming the maximum CPU. You may then want to optimize the query to minimize CPU usage.

Maximum elapsed time

Indicates the running time of each execution of the top query.

Seconds

Use the detailed diagnosis of this measure to view the top-5 (by default) queries that are taking too long to execute. From this, you can easily pick that query with the maximum execution time. You may then want to optimize the query to minimize execution time.