messagesare flushed in a least-recently-used fashion.
Thisoption is provided primarily for customers considering a single
consolidateddatabase for thousands of remote databases.
Tuningincoming message pollingWhenrunning a Message Agent in continuous mode, typically at a
consolidateddatabase site, you can control how often it polls for incoming
messages,and how “patient” it is in waiting for messages that arrive out of
orderbefore requesting that the message be resent. Tuningthese aspects of
thebehavior can have a significant effect on performance in some
circumstances.
Issuesto consider Theissues to consider when tuning the message-receiving process are
similarto those when tuning the message-sending process.
♦Regularmessages Yourchoices dictate how often the Message Agent
pollsfor incoming messages from remote databases.
♦Resendrequests Youcan control how many polls to wait until an
out-of-ordermessage arrives, before requesting that it be resent.
♦Processingincoming messages Ifyour polling period for incoming
messagesis too long, compared to the frequency with which messages
arearriving, you could end up with messages sitting in the queue, waiting
tobe processed. Ifyour polling period is too short, you will waste
resourcespolling when no messages are in the queue.
☞Formore information on the message sending process, see “Tuning the
messagesending process” on page 232.
Pollinginterval
Bydefault, a Message Agent running in continuous mode polls one minute
afterfinishing the previous poll, to see whether new messages have arrived.
Youcan configure the polling interval using the -rd option.
Thedefault polling interval from the end of one poll to the start of another is
oneminute. Youcan poll more frequently using a value in seconds, as in the
followingcommand line:
dbremote -rd 30s
Alternatively,you can poll less frequently, as in the following command line,
whichpolls everyfive minutes:
dbremote -rd 5
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