Suppose you have a very small polling interval, and a message system that does not preserve the order in which messages arrive. It may be common for out-of-sequence messages to arrive after two or three polls have been completed. In this example, it is recommended that you use the -rp option to increase the SQL Remote Message Agent (dbremote) patience so that a large number of unnecessary resend requests are not sent. The -rp option is often used in conjunction with the -rd option that sets the polling interval. See Adjusting the polling interval to check for new messages.

There are two remote users, named user1 and user2, both of which run the SQL Remote Message Agent (dbremote) with a polling interval of 30 seconds and a patience of 3 polls. For example, they use the following command to run their SQL Remote Message Agents (dbremote):

dbremote -c "DSN=SQL Anywhere 12 Demo"  -rd 30s -rp 3

In the following sequence of operations, messages are marked as userX.n where X is the user name and n is the message number. For example, user1.5 is the fifth message from user1. The SQL Remote Message Agent (dbremote) expects messages to start at number 1 for both users.

At time 0 seconds:

At time 30 seconds:

At time 60 seconds:

At time 90 seconds:

When a user receives a new message, it resets the SQL Remote Message Agent (dbremote) patience even if that message is not the one expected.

At time 120 seconds:

• Improving performance when receiving messages
• Adjusting the polling interval to check for new messages
• Adjusting throughput by caching received messages
• Adjusting the number of worker threads
• Improving performance when sending messages