TibrvTransport.requestReliability()
Method
Declaration
voidrequestReliability(double reliability)throws TibrvException
Purpose
Request reliability interval (message retention time) for a service.
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Parameter |
Description |
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Request this reliability interval (in seconds). This value must be greater than zero. |
Remarks
This call lets application programs shorten the reliability interval of the specific service associated with a transport object. Successful calls change the daemon’s reliability interval for all transports within the application process that use the same service.
Programs can request reliability only from daemons of release 8.2 or later.
An application can request a shorter retention time than the value that governs the daemon as a whole (either the factory default or the daemons -reliability parameter). The daemon’s governing value silently overrides calls that request a longer retention time.
Maximum Value Rule
Client transport objects that connect to the same daemon could specify different reliability intervals on the same service—whether by requesting a reliability value, or by using the daemon’s effective value. In this situation, the daemon selects the largest potential value from among all the transports on that service, and uses that maximum value as the effective reliability interval for the service (that is, for all the transports on the service). This method of resolution favors the more stringent reliability requirements. (Contrast this rule with the Lower Value Rule that applies between two daemons.)
Whenever a transport connects, requests reliability, or disconnects from the daemon, the daemon recalculates the reliability interval for the corresponding service, by selecting the largest value of all transports communicating on that service.
When recomputing the reliability interval would result in a shorter retention time, the daemon delays using the new value until after an interval equivalent to the older (longer) retention time. This delay ensures that the daemon retains message data at least as long as the effective reliability interval at the time the message is sent.
See Also
Reliability and Message Retention Time on page 29 in
Lower Value Rule on page 30 in
Changing the Reliability Interval within an Application Program on page 31 in
Reliable Message Delivery on page 34 in