18.1 Optimizing Client/Server Processing

18.1.1 Adjusting the Number of Client/Server Threads

When the POA is configured with client/server processing enabled, it starts client/server handler threads to respond to current client/server requests, up to the number of threads specified by the Client/Server Handler Threads option. To respond to occasional heavy loads, the POA can increase the number of client/server handler threads above the specified amount if CPU utilization is below the threshold established by the CPU Utilization setting. When the POA rereads its configuration information, the number of client/server handler threads drops back within the configured limit. You can determine how often this happens by checking the Client/Server Pending Requests History page in the POA console.

If the POA is frequently not keeping up with the client/server requests from GroupWise client users, you can increase the maximum number of client/server handler threads so the POA can create additional threads as needed. The default is 10 client/server handler threads; valid values range from 1 to 99.

If GroupWise client users cannot connect to the POA immediately or if response is sluggish, you can increase the number of threads.

  1. In the GroupWise Admin console, browse to and click the POA.

  2. Click the Agent Settings tab, and locate the Client/Server section.

  3. Increase the number in the Client/Server Handler Threads field to increase the maximum number of threads the POA can create for client/server processing.

    The optimum number of threads for a POA is affected by many factors, including available system resources, number of users in Caching mode, number of users priming Caching mailboxes, and so on.

    Plan on at least one client/server handler thread per 20-30 client/server users. Or, you can increase the number of client/server handler threads in increments of three to five threads until acceptable throughput is reached. Another approach is to set the value high initially and then monitor thread usage with the C/S Handler Threads link on the Status page of the POA console. If some of the threads always have a count of 0 (zero), meaning they are never used, you can decrease the number of client/server handler threads accordingly.

  4. Click Save, then click Close to return to the main Admin console window.

Corresponding Startup Switches: You can also use the ‑‑tcpthreads switch in the POA startup file to adjust the number of POA client/server handler threads.

POA Console: The Status page helps you assess whether the POA is currently meeting the client/server needs of the post office. Under the Thread Status heading, click C/S Handler Threads to display the workload and status of the client/server handler threads.

If the POA console is password protected as described in Section 16.1, Configuring the POA Console, you can change the number of client/server handler threads on the Configuration page. Under Performance Settings, click C/S Handler Threads.

18.1.2 Adjusting the Number of Client/Server Connections

Connections are the number of “sockets” through which client/server requests are communicated from the GroupWise client to the POA.

  • Application connections: Each GroupWise user uses one application connection when he or she starts GroupWise. Depending on what activities the user is doing in the GroupWise client, additional application connections are used. For example, the GroupWise Address Book and GroupWise Notify use individual application connections. The default maximum number of application connections is 2048. You should plan about 3 to 4 application connections per user, so the default is appropriate for a post office of about 500 users.

  • Physical connections: Each GroupWise user could have zero or multiple active physical connections. One physical connection can accommodate multiple application connections. Inactive physical connections periodically time out and are then closed by the clients and the POA. The default maximum number of physical connections is 2048. You should plan about 1 to 2 physical connections per user, so the default is appropriate for a post office of about 500 users.

If the POA is configured with too few connections to accommodate the number of users in the post office, the POA can encounter an error condition such as GWPOA: Application connection table full.

  1. In the GroupWise Admin console, browse to and click the POA.

  2. Click the Agent Settings tab, and locate the Client/Server section.

  3. Increase the number in the Max Physical Connections field to increase the amount of TCP/IP traffic the POA can accommodate.

  4. Increase the number in the Max App Connections field to increase the number of activities the attached users can perform concurrently.

  5. Click Save, then click Close to return to the main Admin console window.

Corresponding Startup Switches: You can also use the ‑‑maxappconns and ‑‑maxphysconns switches in the POA startup file to adjust the POA client/server processing.

POA Console: The Status page helps you assess whether the POA is currently meeting the client/server needs of the post office. Under the Statistics heading, click C/S Requests Pending. You can also manually select multiple log files to search in order to display a history of times during the last 24 hours when the POA was unable to respond immediately to client/server requests.

18.1.3 Optimizing Thread Management

The availability of client/server threads affects a GroupWise user’s experience in the GroupWise client. When the POA is working under a heavy load, users can experience degraded performance when sufficient client/server threads are not available. To maintain the best possible performance for GroupWise users, the POA automatically favors client/server processing over message handling. By default, under a heavy load, the POA automatically decreases the number of message handler threads and increases the number of client/server threads to favor client connections while keeping the total number of threads constant. This behavior benefits users because they are more aware of client performance than they are of messages that they have not yet received.

However, one result of this default behavior is that the message queues can back up during times of heavy client activity. If necessary, you can manually adjust the POA’s ratio of client/server threads and message handler threads to help the POA clear out its message queues.

  1. Ensure that the POA console is password protected.

    For instructions, see Section 16.1, Configuring the POA Console.

  2. In the POA console, click Configuration > Message Worker Threads.

  3. Increase the number in the Worker Yields to C/S Level field to increase the amount of time that the POA waits before reallocating message worker threads as client/server threads.

    Increasing this setting configures the POA to continue processing message queues rather than focusing on client/server processing. Valid values range from 0 (zero) to five. Select 0 to turn off the automatic thread adjustments. The settings of 1 through 5 represent increasing amounts of time, but not a specific number of seconds or minutes.

  4. Click Submit after changing the setting.

    The POA automatically restarts to put the new setting into effect.

  5. Experiment with the setting until you achieve a proper balance between client/server processing and message processing.