[AMQ-6203] KahaDB: Allow rewrite of message acks in older logs which prevent cleanup

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 5.13.0, 5.13.1, 5.12.3, 5.13.2
• Fix Version/s: 5.13.3, 5.14.0
• Component/s: KahaDB
• Assignee: Timothy A. Bish
• Reporter: Timothy A. Bish
• Created: 09/Mar/16 15:02
• Updated: 09/Aug/16 22:22
• Resolved: 18/Mar/16 19:32

Description

There are cases where a chain of journal logs can grow due to acks for messages in older logs needing to be kept so that on recovery proper state can be restored and older messages not be resurrected.

In many cases just moving the acks from one log forward to a new log can free an entire chain during subsequent GC cycles. The 'compacted' ack log can be written during the time between GC cycles without the index lock being held meaning normal broker operations can continue.

Issue Links

• is related to: AMQ-6285 MessageDatabase doesn't properly cleanup the checkpoint scheduler on shutdown
• is related to: AMQ-6287 Message ack rewrite task doesn't properly release index lock
• is related to: AMQ-6288 Message ack compaction needs to acquire the checkpoint lock
• is related to: AMQ-6303 Message ack rewrite does not always set the right journal file type code
• is related to: AMQ-3978 Allow KahaDB to "compact" journal files to remove messages that are no longer needed