Monitoring the USERS Startup Parameter

This section applies to all file pool servers.

When server processing starts in multiple user mode, it uses the USERS value to configure itself to handle the work that the specified number of users might cause. When the USERS startup parameter is set, the number of agents created should be sufficient such that a user making a server request never has to wait for an agent. If there is an insufficient number of agents, users are queued until one is available—this may result in poor server response time. If there are too many, virtual storage in the server machine is wasted.

To monitor this limit, enter a QUERY FILEPOOL AGENT command and look at the Active Agents Highest Value in the Agent Information. It is best to check this limit late in the day after peak work loads have occurred. If you check the Active Agents Highest Value and it is close to or equal to the Total Number of Agents the server has created, you should consider increasing the USERS value in the DMSPARMS file. (For more information, see USERS parameter.)

Suppose, for example, your USERS value is set to 129. At the end of the day you enter QUERY FILEPOOL AGENT and find the Active Agents Highest Value is 19 and Total Number of Agents is 20. This indicates the server is operating near peak capacity for its configuration. If the Active Agents Highest Value is equal to the Total Number of Agents, you know that at some time during server operation the server was operating at peak capacity and may have, in fact, been overloaded. Because the Active Agents Highest Value never exceeds the Total Number of Agents, an equality of the two values indicates an overload. Further support for this conclusion would be complaints from users that their applications are failing with reason codes of 97400 (or they are receiving message DMS1151E), even though the server is available and can process other commands.

The amount by which you should increase USERS is subjective. If file pool use has in the past had relatively slow growth, a nominal increase might be sufficient. If your file pool has had rapid growth, a proportionally higher increase is warranted.