[PHOENIX-3611] ConnectionQueryService cache should expire LRU entries

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.8.0, 4.9.0
• Fix Version/s: 4.10.0
• Assignee: Geoffrey Jacoby
• Reporter: Geoffrey Jacoby
• Created: 19/Jan/17 18:06
• Updated: 26/Jan/17 03:10
• Resolved: 26/Jan/17 03:10

Description

Currently the cache of ConnectionInfo/ConnectionQueryServicesImpl can hold its entries forever. This can potentially lead to orphan cache entries, and since each ConnectionQueryServicesImpl object has an HConnection, it can also lead to leaked connections.

Due to the way that ConnectionInfo hashing works (see PHOENIX-3126 and PHOENIX-3607), this is particularly likely on a secure cluster.

The cache should be changed into an LRU-style cache with a fixed size and gradual expiration.