[HBASE-16275] Change ServerManager#onlineServers from ConcurrentHashMap to ConcurrentSkipListMap

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 1.4.0, 0.98.21, 2.0.0
• Assignee: Hua Xiang
• Reporter: Hua Xiang
• Created: 22/Jul/16 20:58
• Updated: 02/Aug/16 17:52
• Resolved: 28/Jul/16 18:20

Description

In Class ServerManager, onlineServers is declared as ConcurrentHashMap. In findServerWithSameHostnamePortWithLock(), it has to do a loop to find if there is a ServerName with same host:port pair. If replaced with ConcurrentSkipListMap, findServerWithSameHostnamePortWithLock() can be replaced with a O(logN) implementation.

I run some performance comparison(test the function only), it seems that there is no difference if there are 1000 servers. With more servers, ConcurrentSkipListMap implementation is going to win big.

Issue Links

• depends upon: HBASE-16272 Overflow in ServerName's compareTo method