When the number of messages to be delivered to local CommuniGate Pro accounts is expected to be higher than 1 message/second, you should allocate more "processors" in the Local Delivery Module. This is especially important for environments that process heavy inbound SMTP traffic (often used as a performance test environment). Insufficient number of Local Delivery module processors (threads) may result in excessive Queue growth and large latency in message delivery. You should watch the Local Delivery module Monitor and allocate more processors (threads) to that module if you see that the module Queue size grows to more than 200-300 messages. Do not allocate additional threads if, for example, you have 10 Local Delivery processors and see the waiting Local Delivery queue of 200 messages: this Queue size introduces only 1-2 seconds delivery latency. Increase the number of Local Delivery threads only if you see that Queue growing.
Some types of storage arrays benefit from a significant number of parallel delivery threads. For example, there are some NFS arrays which can deliver messages more efficiently with 100 Local Delivery processors than with 10, given the same number of messages. The storage vendor should be requested to provide information about the optimal number of parallel write operations for each system accessing the array, and the number of CommuniGate Pro Local Delivery processors can be adjusted to hit this target number. As Local Delivery processors are static (the configured number of processors remain in existence consistently throughout the life of the process), it is important to configure enough processors but wasteful of system resources to configure vastly too many.
Administrators of heavily loaded servers may want to disable the Use Conservative Info Updates option (located in the Local Account Manager panel on the Others page in the WebAdmin Settings realm). Disabling this option decreases the load on the file I/O subsystem.