User's Manual

Chapter 14. Utilities and Options Reference
than n operations together with transactions that follow. The default is
twenty operations. Increasing the value of n can speed up processing of
incoming messages, by doing less commits. However, it can also cause
deadlock and blocking by increasing the size of transactions.
–I Scan transactions from the transaction log into the stable queue. This
option is available for Adaptive Server Enterprise only. It is used when you
wish to run a separate copy of the Message Agent for scanning the
transaction log and for sending and receiving messages.
If none of -r, -I, or -s is specified, the Message Agent executes all three
phases. Otherwise, only the indicated phases are executed.
☞ For more information, see “Running multiple Message Agents” on
page 269.
–k Close window on completion when used together with the -o parameter.
–l length Specifies the maximum length of each message to be sent, in
bytes. Longer transactions are split into more than one message. The default
is 50000 bytes and the minimum length is 10000.
Caution
The maximum message length must be the same at all sites in an installa-
tion.
For platforms with restricted memory allocation, the value must be less than
the maximum memory allocation of the operating system.
–m size Specifies a maximum amount of memory to be used by the
Message Agent for building messages and caching incoming messages. The
allowed size can be specified as n (in bytes), n K, or n M. The default is
2048K (2M).
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 are
receiving the same operations. When the memory being used exceeds the -m
value, messages are sent before reaching their maximum size (as specified
by the -l option).
When messages arrive, they are stored in memory by the Message Agent
until they are applied. This caching of messages prevents rereading of
messages that are out of order from the message system, which may lower
performance on large installations. When the memory usage specified using
the -m option is exceeded, messages are flushed in a least-recently used
fashion.
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