[BOOKKEEPER-550] Reduce unnecessary acquire operation in AbstractSubscriptionManager and BookkeeperPersistenceManager

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Not A Problem
• Component/s: hedwig-server
• Assignee: Jiannan Wang
• Reporter: Jiannan Wang
• Created: 19/Jan/13 16:51
• Updated: 20/Jan/13 06:42
• Resolved: 20/Jan/13 06:42

Description

After topic ownership is figured out by topic manager, AbstractSubscriptionManager and BookkeeperPersistenceManage will be notified to acquire topic. Then both AbstractSubscriptionManager and BookkeeperPersistenceManage have a first check on whether the topic is successfully acquired before, if yes the acquire op response right away, or else they will read metadata and do further jobs.

The problem is that acquire operation may take very long time to finish (especially for BookkeeperPersistenceManage), so if many requests of a same topic come to Hub, all of these request will issue a new acquire operation. The situation may go very very bad if there are many sub/closesub and metadata storage get small throughput.