TP: message bundling based on count per dest rather than global count --------------------------------------------------------------------- Key: JGRP-1601 URL: https://issues.jboss.org/browse/JGRP-1601 Project: JGroups Issue Type: Enhancement Reporter: Bela Ban Assignee: Bela Ban Fix For: 3.3 Currently, the message bundlers in TP count accumulated message sizes based on a global 'count' variable. So both multicast messages, and messages to A, B and C increment count. If we only sent a message bundle to destination T if (1) there are no more messages in the queue or (2) the accumulated bytes for T would exceed max_bundle_size, then we might send more batches and fewer individual messages. Example: * We're sending 10K messages and max_bundle_size=55K * Different threads concurrently send ** T1: 6 multicast messages ** T2: 6 messages to A ** T3: 6 messages to B ** T4: 6 messages to C ** T5: 6 messages to D ** T6: 6 messages to E * If each of the threads gets 1 message in, we've reached the max_bundle_size and will send a message bundle for the multicast, 1 bundle for the unicast message to A, 1 for the message to B and so on, for a total of 5 bundles with *one* message only ! * If we counted bytes per destination, we'd be able to send a bundle of 5 messages to the multicast dest, 5 to A, 5 to B and so on. ** This might lead to better performance, as message batches on the receivers tend to be filled better, especially if we have many messages being sent concurrently. With a counter per dest we'd ideally send 6 message batches (containing 6 messages each); whereas with 1 count variable we'd send 36 batches each containing only 1 message ! Investigate whether it would make sense (perf-wise) to have count being associated with individual destinations rather than having a global count variable.