For each connection, OpenEdge allocates the memory for the send and response queues with a default size. If asynchronous requests are such that they exceed the send and response queue size, OpenEdge stores additional queued requests in a temp-table associated with the client session. Thus, performance can vary based on whether requests are stored in memory or in the temp-table.

To help you maximize the performance of asynchronous requests, OpenEdge provides the Async Queue Size (-asyncqueuesize) client startup parameter. This parameter allows you to specify the number of bytes that you want OpenEdge to allocate for the send and response queues for a PAS for OpenEdge connection.

The Async Queue Size parameter only applies when you create the PAS for OpenEdge connection on the client, and it applies equally to each such connection. Also, although OpenEdge creates the send and response queues for each connection, they are not used unless you make asynchronous requests to the PAS for OpenEdge instance. Thus, you can maximize the PAS for OpenEdge performance by choosing a value based on the amount of data that you expect to flow between the client and the PAS for OpenEdge instance for these asynchronous requests. Similarly, if you are making no asynchronous requests, you can choose a low value to reduce the space allocated to queues that you are not planning to use.

For more information on this startup parameter, see the Async Queue Size (-asyncqueuesize) entry in OpenEdge Deployment: Startup Command and Parameter Reference.