[AMQ-5603] Consider preallocation of journal files in batch increments

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 5.14.0
• Component/s: Message Store
• Labels: kahaDB perfomance
• Assignee: Gary Tully
• Reporter: Christian Posta
• Created: 20/Feb/15 16:29
• Updated: 16/Dec/16 18:40
• Resolved: 03/May/16 11:37

Description

Right now (as of ActiveMQ 5.12 release) we preallocate journal files, but the only scope is for entire journal file. The [potential] issue with that is if user configures large journal file sizes, we can end up stalling writes during log rotation because of the allocation process. There are two ways to do the allocation, configurable to do it in userspace, or defer to kernel space, but nevertheless it would be good to avoid this issue altogether by preallocating in small batch sizes regardless of the journal max file size.

Issue Links

• is related to: AMQ-6545 Deadlock can occur during journal file rotation
• is related to: AMQ-4947 Reduce the reliance on fsync when writing to disk
• is related to: AMQ-5578 preallocate journal files