Setting the send frequency

To run the Message Agent (dbremote) in continuous mode, for example on the consolidated database, you must ensure that every REMOTE user either has a send frequency specified. In continuous mode, the Message Agent (dbremote) sends messages at the times specified with the SEND AT or SEND EVERY property.

The Message Agent (dbremote) supports the following send frequency values:

  • SEND EVERY   Specifies a length of time to wait between sending messages.

    When any user with SEND EVERY set is sent messages, all users with the same frequency are sent messages at the same time. For example, all remote users who receive updates every twelve hours are sent updates at the same time, rather than being staggered. This reduces the number of times the SQL Anywhere transaction log has to be processed. You should use as few unique frequencies as possible.

    A send frequency can be specified in hours, minutes, and seconds in the format HH:MM:SS.

  • SEND AT   Specifies a time of day at which messages are sent.

    Updates are sent daily at the specified time. You should use as few distinct times as possible rather than staggering the send times. You should choose times when the database is not busy.

  • Default setting (no SEND clause)   If any user has no SEND AT or SEND EVERY clause specified, the Message Agent (dbremote) runs in batch mode, sending messages every time it is run, and then stopping. See Run the Message Agent (dbremote) in batch mode.

Sending messages too frequently

If you send messages frequently, there is a greater chance of small messages being sent. Sending messages less frequently allows more instructions to be grouped in a single message. If a large number of small messages is a concern for your message system, then you should avoid using very small send frequency periods.

To set the send frequency (Sybase Central)

  1. Connect to the database as a user with DBA authority.

  2. In the left pane, select the SQL Remote Users directory.

  3. Right-click a user and choose Properties.

  4. Click the SQL Remote tab.

  5. Select either Send Every or Send Daily At and specify a time.

See also
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