[HBASE-16010] Put draining function through Admin API

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 2.0.0
• Hadoop Flags: Reviewed
• Assignee: Matt Warhaftig
• Reporter: Jerry He
• Created: 10/Jun/16 23:14
• Updated: 17/Jun/22 05:00
• Resolved: 11/Oct/17 23:17

Description

Currently, there is no Amdin API for draining function. Client has to interact directly with Zookeeper draining node to add and remove draining servers.
For example, in draining_servers.rb:

  zkw = org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher.new(config, "draining_servers", nil)
  parentZnode = zkw.drainingZNode

  begin
    for server in servers
      node = ZKUtil.joinZNode(parentZnode, server)
      ZKUtil.createAndFailSilent(zkw, node)
    end
  ensure
    zkw.close()
  end

This is not good in cases like secure clusters with protected Zookeeper nodes.
Let's put draining function through Admin API.

Issue Links

• duplicates: HBASE-17322 New API to get the list of draining region servers
• is related to: HBASE-17304 Avoid draining region servers in draining mode while moving the regions at client side i.e. in region_mover.rb
• is related to: HBASE-10367 RegionServer graceful stop / decommissioning

Sub-Tasks

• Add ACL to the new region server drain related API: Closed
• Fix or provide shell scripts to drain and decommission region server: Resolved