Message queueing in middleware by a message broker

A computer program product comprising a computer readable storage medium, wherein the computer readable storage medium is not a transitory signal per se, the computer readable storage medium having program instructions embodied therewith, the program instructions configured, when executed by at least one computer, to cause the at least one computer to:

• receive, at a first message queue of a plurality of message queues, a first synchronous message from a first client application of a plurality of client applications;
• determine that at a time the first synchronous message is received there is an earlier-received message waiting in the first message queue, wherein the earlier-received message is from a different client application;
• and
• coalesce, in response to the determination, the first synchronous message with the earlier-received message such that a task associated with the first message queue is executed only once for both messages and a notice of the execution is returned to the first client application;
• wherein the earlier-received message is also synchronous such that the notice of the execution is also returned to the different client application.

A system comprising:

• a memory;
• and
• a processor in communication with the memory, the processor configured to obtain instructions from the memory that cause the processor to perform a method comprising:
• receiving, at a first message queue of a plurality of message queues, a first synchronous message from a first client application of a plurality of client applications;
• determining that at a time the first synchronous message is received there is an earlier-received message waiting in the first message queue, wherein the earlier-received message is from a different client application;
• coalescing, in response to the determination, the first synchronous message with the earlier-received message such that a task associated with the first message queue is executed only once for both messages and a notice of the execution is returned to the first client application;
• receiving, at the first message queue and while the earlier-received message is waiting in the first message queue, a second message;
• determining, based on an indicator in the second message, that the second message is not to be coalesced with the earlier-received message;
• and
• placing, in response to the determination based on the indicator, the second message behind with the earlier-received message in the first message queue.