[BOOKKEEPER-664] Compaction increases latency on journal writes

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.2.1
• Fix Version/s: 4.2.2, 4.3.0
• Component/s: bookkeeper-server
• Assignee: Ivan Kelly
• Reporter: Ivan Kelly
• Created: 29/Jul/13 12:35
• Updated: 22/Oct/13 06:13
• Resolved: 22/Oct/13 05:44

Description

Compaction writes to the journal to avoid data loss (see BOOKKEEPER-530). BOOKKEEPER-530 correctly identified that this may affect latency on the journal but we have observed this since in production. It is possible to avoid the journal completely, as twitter do in their github branch. Basically, we need to write to the entrylogger first, flush the entry log and then add to the index.