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Reliable Delivery & Latency

TIBCO Rendezvous software features reliable delivery, which compensates for brief network failures. When low-latency is a priority, it might be advantageous to reconfigure—or even disable—this feature.

Reliability Overview

The receiving TIBCO Rendezvous daemon detects missing packets and requests that the sending daemon retransmit them. The sending daemon stores outbound messages for a limited period of time, so it can retransmit the information upon request. It discards old messages after the time period elapses, and cannot retransmit after that time.

Reduced Reliability

For ordinary daemon processes, the default reliability time period is 60 seconds. However, for extremely time-sensitive data, a fraction of a second can make the difference between a message that arrives in time to be useful, and a message that is no longer relevant. In such situations, a reliability window of 60 seconds could be counterproductive. Instead, IPM lowers this default reliability window to 5 seconds. This lower reliability window could reduce memory usage.

TIBCO Rendezvous software attempts to recover a missed packet until the reliability period expires for that packet. From this perspective, the reliability period also specifies the maximum acceptable delay for message data. In some applications, even 5 seconds (or even 1 second) might far exceed the threshold of message usefulness.

Disabling Reliability

If the potential delay inherent in any retransmission exceeds the threshold of message usefulness, you might experiment with disabling the reliable delivery feature entirely. Disabling reliability eliminates any possibility that senders could retransmit missed data packets. The resulting data loss might be an acceptable trade-off when low latency is a higher priority.

To disable reliable delivery, reduce the reliability window to zero.

Configuring Reliability

The -reliability parameter specifies the message retention time (in seconds).

To change the reliability window of a sender, supply a value for the -reliability parameter. Values must be non-negative integers.

See Also

For a complete discussion the concept of reliability, see Reliability and Message Retention Time in TIBCO Rendezvous Administration.

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