Db2 Agents Test

An agent is a process or thread that carries out the requests made by a client application. Each connected application is served by exactly 1 coordinator agent and possibly, a set of subordinator agents or subagents. Subagents are used for parallel SQL processing in partitioned databases and on SMP machines.

For partitioned database environments and environments with intra-partition parallelism enabled, each partition (that is, each database server or node) has its own pool of agents from which subagents are drawn. Because of this pool, subagents do not have to be created and destroyed each time one is needed or has finished its work. The subagents can remain as associated agents in the pool and be used by the database manager for new requests from the application they are associated with.

The Db2 Agents test monitors how effectively the agent pool has been utilized.

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 DB2 database server being monitored

Configurable parameters for the test
  1. TEST PERIOD – How often should the test be executed
  2. HostThe IP address of the DB2 server
  3. PortThe port number through which the DB2 server communicates. The default port is 50000.
  4. user - Specify the name of the user who has any of the following privileges to the specified DATABASE: SYSADM or SYSCTRL or SYSMAINT or SYSMON. You can create a separate user on the OS hosting the DB2 server for this purpose, and assign any of the aforesaid privileges to that user. The steps for the same are detailed in the Creating a Special User for Monitoring DB2.
  5. password - Enter the password of the specified USER in the PASSWORD text box.
  6. confirm password – Confirm the password by retyping it here.
  7. database - Specify the name of the database on the monitored DB2 server to be used by this test
Measurements made by the test
Measurement Description Measurement Unit Interpretation

Total agents:

Indicates the total number of agents currently registered in the database manager instance that is being monitored (Sum of coordinator agents and subagents).

Number

This measure can be used to evaluate the setting for MAXAGENTS configuration parameter.

Idle agents :

Indicates the number of agents in the agent pool that are currently unassigned to an application and are, therefore, “idle”.

Number

Having idle agents available to service requests for agents can improve performance. So you can use this measure to help set the NUM_POOLAGENTS configuration parameter.

Agents waiting on token:

Indicates the percentage of agents waiting for a token so they can execute a transaction in the database manager.

Percent

You can use this element to help evaluate your setting for the MAXCAGENTS configuration parameter. Each application has a dedicated coordinator agent to process database requests within the database manager. Each agent has to get a token before it can execute a transaction. The maximum number of agents that can execute database manager transactions is limited by the configuration parameter MAXCAGENTS.

Agents creation ratio:

Indicates the ratio of number of agents assigned directly from agent pool to the total number of agents used to service requests.

Percent

A high percentage indicates the effectiveness of the agent pool. A consistent low value indicates that the number of agents in the agent pool are not adequate to service requests. You might want to consider increasing the NUM_POOLAGENTS setting in this case.

Stolen Agents:

Indicates the number of times that agents are stolen from an application. Agents are stolen when an idle agent associated with an application is reassigned to work on a different application.

Number

If this value is high, consider increasing the NUM_POOLAGENTS configuration parameter.