[AMQ-3242] Change prefetch size limit for topics from 32766 to 32767

• Type: Improvement
• Status: Closed
• Priority: Trivial
• Resolution: Fixed
• Fix Version/s: 5.6.0
• Assignee: Unassigned
• Reporter: Robert Liguori
• Created: 27/Mar/11 02:02
• Updated: 23/Sep/11 19:31
• Resolved: 23/Sep/11 18:59

Description

The default prefetch size limit for topics is noted as 32766; http://activemq.apache.org/performance-tuning.html

The FUSE source documentation (http://fusesource.com/docs/broker/5.4/tuning/index.html) states, "Default prefetch limit is 32766. The default limit of 32766 is the largest value of a short and is the maximum possible value of the prefetch limit.".

The largest value for a short actually is 32767 (http://java.sun.com/docs/books/jls/second_edition/html/typesValues.doc.html).

This is really a trivial issue, but should the default prefetch limit for topics be changed from 32766 to 32767 to reflect the actual ceiling?

And of course, I would recommend changing the automatic setting to 32767, when the maximum has been exceeded. The following warning shows the applied default of 32766:
16:22:40 WARN maximum prefetch limit has been reset from 50000 to 32766