Adjusting throughput by caching messages

The Message Agent (dbremote) caches messages to be sent in a configurable area of memory.

When all remote databases are receiving unique subsets of the operations being replicated, a separate message for each remote database is built up concurrently. Only one message is built for a group of remote users that is receiving the same operations. Messages are sent when:

  • The send frequency is reached.

  • When the cache memory being used exceeds the -m value.

  • When the size of the message reaches its maximum size (as specified by the -l option).

Specifying the message cache size

The size of the message cache is specified on the Message Agent (dbremote) command, using the -m option.

The -m option specifies the maximum amount of memory to be used by the Message Agent (dbremote) for building messages. The allowed size can be specified as n (in bytes), nK, or nM. The default is 2048K (2M).

The -m option is useful when you have a single consolidated database and a large number of remote databases. See the -m option Message Agent (dbremote).

Example

The following command starts a Message Agent (dbremote) using 12 MB of memory as a message cache:

dbremote -c "DSN=SQL Anywhere 11 Demo" -m 12M
See also