Novell Doc: GroupWise 7 Administration Guide - Optimizing Mapped/UNC Links

43.2 Optimizing Mapped/UNC Links

If you must use mapped or UNC links, you can fine-tune how the MTA polls its input queues.

NOTE:The Linux MTA does not use mapped or UNC links.

43.2.1 Using TCP/IP Links between Locations

TCP/IP links between domains or between a domain and its post offices are faster than mapped or UNC links because the MTA is immediately notified whenever a new message arrives. This eliminates the latency involved in scanning input directories for messages to process. To change from mapped or UNC links to TCP/IP links, see Using TCP/IP Links between Domains and Using TCP/IP Links between a Domain and its Post Offices

43.2.2 Adjusting MTA Polling of Input Queues in the Domain, Post Offices, and Gateways

When using mapped or UNC links between the local domain and its post offices and other domains, the MTA can create a lot of network traffic just scanning its input queues, especially if the message load is light. This can be minimized by setting the scan cycle to a higher number. On the other hand, if the scan cycle is set too high, important messages might have to wait in the input queues to be picked up by the MTA. The MTA’s scan cycle settings also control how often it communicates with gateways installed in the domain.

By default, when using mapped or UNC links, the MTA scans its high priority queues every 5 seconds and its regular and low priority queues every 15 seconds. You can adjust the scan cycle settings to meet the needs of your GroupWise® system.

In ConsoleOne®, browse to and right-click the MTA object, then click Properties.
Click GroupWise > Agent Settings to display the Agent Settings page.
Decrease the number of seconds in the Scan Cycle field if you want the MTA to scan the regular and low priority queues (2-7) more often.

or

Increase the number of seconds in Scan Cycle field if you want the MTA to scan the regular and low priority queues (2-7) less often.
Decrease the number of seconds in the Scan High field if you want the MTA to scan the high priority queues (0-1) more often.

or

Increase the number of seconds in the Scan High field if you want the MTA to scan high priority queues (0-1) less often.

For the locations and specific uses of the MTA input queues, see Message Transfer/Storage Directories in GroupWise 7 Troubleshooting 3: Message Flow and Directory Structure.
Click OK to save the new scan cycle settings.

ConsoleOne then notifies the MTA to restart so the new settings can be put into effect.

Corresponding Startup Switches You can also use the /cylo and /cyhi switches in the MTA startup file to adjust the MTA scan cycle.

MTA Web Console You can check the current MTA scan cycle on the Configuration page under the Performance Settings heading.

43.2.3 Adjusting the Number of MTA Scanner Threads for the Domain and Post Offices

When using mapped or UNC links, the MTA automatically starts one high priority scanner thread for the priority 0 and 1 subdirectories of its input queues. It also starts a second scanner thread for the priority 2-7 subdirectories. This default configuration can create a bottleneck under some circumstances:

The priority 0 subdirectory is used for Busy Search requests from GroupWise client users. The priority 1 subdirectory is used by GroupWise Remote users. If your GroupWise system serves a large number of very active GroupWise Remote users, the MTA can stay busy processing requests from Remote users, causing other users to experience a delay in response to a Busy Search request.
The priority 2 subdirectory is used for administrative messages and high priority user messages. Priority 3-7 subdirectories are used for regular and low priority messages and status messages. Certain administrative activities, such as moving a large number of users or purging trash, can create numerous administrative messages in the priority 2 subdirectory, causing users to experience a delay in receiving high priority as well as regular messages.

For the locations of the MTA input queues, see Message Transfer/Storage Directories in GroupWise 7 Troubleshooting 3: Message Flow and Directory Structure.

You can configure the MTA so that it starts separate scanner threads to service the priority 0 and 1 subdirectories and/or separate scanner threads for the 2-3 and 4-7 subdirectories.

IMPORTANT:Do not try to run more than one MTA for the same domain.

In ConsoleOne, browse to and right-click the MTA object, then click Properties.
Click GroupWise > Agent Settings to display the Agent Settings page.
Select Use 2nd High Priority Scanner to provide separate MTA scanner threads for Busy Searches and GroupWise Remote users.

Select Use 2nd Mail Priority Scanner to provide separate MTA scanner threads for administrative messages and high priority user messages vs. regular and low priority messages.

These settings can be used separately (creating three MTA scanner threads) or together (creating four MTA scanner threads).

Primary Use	Priority Directory	Default Operation	2nd High Priority Scanner	2nd Mail Priority Scanner	Both Second Priority Scanners
Busy searches	wpcsin\0	High priority scanner thread	High priority scanner thread one	High priority scanner thread	High priority scanner thread one
GroupWise Remote user requests	wpcsin\1	High priority scanner thread	High priority scanner thread two	High priority scanner thread	High priority scanner thread two
Administrative requests and high priority messages	wpcsin\2	Mail priority scanner thread	Mail priority scanner thread	Mail priority scanner thread one	Mail priority scanner thread one
High priority statuses	wpcsin\3			Mail priority scanner thread one	Mail priority scanner thread one
Normal priority messages	wpcsin\4			Mail priority scanner thread two	Mail priority scanner thread two
Normal priority statuses	wpcsin\5
Low priority messages	wpcsin\6
Low priority statuses	wpcsin\7
Total Scanner Threads in Use:		2	3	3	4

Click OK to save the new scanner thread settings.

ConsoleOne then notifies the MTA to restart so the new setting can be put into effect.

Corresponding Startup Switches You can also use the /fast0 and /fast4 switches in the MTA startup file to adjust the allocation of MTA scanner threads.

MTA Web Console You can check the current MTA scan cycle on the Configuration page under the Performance Settings heading.