[HBASE-12128] Cache configuration and RpcController selection for Table in Connection

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.0.0, 2.0.0
• Fix Version/s: 0.99.2
• Hadoop Flags: Reviewed
• Assignee: Stephen Yuan Jiang
• Reporter: Andrew Kyle Purtell
• Created: 30/Sep/14 23:00
• Updated: 06/Apr/18 17:55
• Resolved: 25/Nov/14 21:52

Description

Creating Table instances should be lightweight. Apps that manage their own Connections are expected to create Tables on demand for each interaction. However we look up values from Hadoop Configuration when constructing Table objects for storing to some of its fields. Configuration is a heavyweight registry that does a lot of string operations and regex matching. Method calls into Configuration account for 48.25% of CPU time when creating the HTable object in 0.98. Another ~48% of CPU is spent constructing the desired RpcController object via reflection in 0.98. Together this can account for ~20% of total on-CPU time of the client. See parent issue for more detail.

We are using Connection like a factory for Table. We should cache configuration for Table in Connection. We should also create by reflection once and cache the desired RpcController object, and clone it for new Tables.

Issue Links

• relates to: HBASE-12604 Backport HBASE-12128 (Cache configuration and RpcController selection for Table in Connection) to 0.98
• relates to: HBASE-13690 Client Scanner Initialization Reformats strings every time
• relates to: HBASE-13691 HTable and RPC Code Accessing Configuration each time (Blocking)