[BOOKKEEPER-196] Define interface between bookie and ledger storage

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.1.0
• Assignee: Ivan Kelly
• Reporter: Ivan Kelly
• Created: 29/Mar/12 15:03
• Updated: 22/Oct/12 14:50
• Resolved: 17/Apr/12 10:30

Description

EntryLogger and LedgerCache are both part of a very interdependent storage mechanism where entries are interleaved in a single log(EntryLogger) and index files are maintained (LedgerCache). I'd like to experiment with some other schemes (Im not convinced the interleaving is required for high performance). ZOOKEEPER-507 brought in these changes, but it also brought in a lot of other stuff, and I think its the other stuff (specifically taking the writing to separate files out of the critical path) which gave us the performance boost. To do this cleanly, we need a well defined storage interface for this. This JIRA is to provide this. Future work can move the interleaved implementation into another package as org.apache.bookkeeper.bookie is getting a little crowded now.