[AMQ-3206] Unsubscribed durable sub can leave dangling message reference in kahaDB, visible after a restart

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 5.4.2
• Fix Version/s: 5.5.0
• Component/s: Message Store
• Labels: durable kahaDB topic
• Assignee: Gary Tully
• Reporter: Gary Tully
• Created: 07/Mar/11 14:55
• Updated: 23/Apr/12 10:10
• Resolved: 07/Mar/11 14:59

Description

Unsubscribing a durable sub with kahaDB cleans up the expected ack locations but does not update the change to the persistent index. After a restart, the old state is recovered which can lead to invalid references to messages. These references can block journal file deletion when the message is ultimately consumed by all interested subs, Leading to data file build up. The necessary conditions are multiple durable subs with some unsubscribing with a remaining backlog along with broker restarts.