[AMQ-855] Add support for prefetchSize = 0

• Type: New Feature
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 4.0, 4.0.1, 4.0.2
• Fix Version/s: 4.1.0
• Component/s: Broker

Environment

any

• Patch Info: Patch Available
• Assignee: Hiram R. Chirino
• Reporter: Vadim Pesochinskiy
• Created: 01/Aug/06 17:28
• Updated: 16/Oct/06 19:50
• Resolved: 16/Oct/06 19:50

Description

This feature would enable to support following test case:

2 servers are processing 3 submitted jobs with following processing times 10 min, 1 min, 1 min. This sequence should finish in 10 minutes as one service will pick up the 10 minutes job, meanwhile the other one should manage the two 1 minute jobs. Since I cannot set prefetchSize=0, one of the 1 minute jobs is sitting in prefetch buffer and the jobs are processed in 11 minutes instead of 10.

This is simplification of the real scenario where I have about 30 consumers submitting jobs to 20 consumers through AMQ 4.0.1. I have following problems:

• Messages are sitting in prefetch buffer are not available to processors, which results in a lot of idle time.
• Order of processing is random. For some reason Job # 20 is processed after Job # 1500. Since senders are synchronously blocked this can result in time-outs.
• Some requests are real-time, i.e. there is a user waiting, so the system cannot wait, so AMQ-850 does not fix this issue.

Issue Links

• is superceded by: AMQ-122 add support for priority message ordering
• is superceded by: AMQ-850 add the ability to timeout a consumer to prevent a bad, hung or unused consumer consumer from grabbing messages