HBASE-4704 Differential Revision: #117 A JRuby script for identifying active master

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1201828 13f79535-47bb-0310-9956-ffa450edef68

bin/get-active-master.rb

@@ -0,0 +1,45 @@
+#!/usr/bin/env hbase-jruby
+# Copyright 2011 The Apache Software Foundation
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements. See the NOTICE file distributed with this
+# work for additional information regarding copyright ownership. The ASF
+# licenses this file to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+# Prints the hostname of the machine running the active master.
+
+include Java 
+import org.apache.hadoop.hbase.HBaseConfiguration
+import org.apache.hadoop.hbase.ServerName
+import org.apache.hadoop.hbase.zookeeper.ZKUtil
+import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher
+
+# disable debug/info logging on this script for clarity
+log_level = org.apache.log4j.Level::ERROR
+org.apache.log4j.Logger.getLogger('org.apache.hadoop.hbase').setLevel(log_level)
+org.apache.log4j.Logger.getLogger('org.apache.zookeeper').setLevel(log_level)
+
+config = HBaseConfiguration.create
+
+zk = ZooKeeperWatcher.new(config, 'get-active-master', nil)
+begin
+  master_address = ZKUtil.getData(zk, zk.masterAddressZNode)
+  if master_address
+    puts ServerName.parseVersionedServerName(master_address).getHostname()
+  else
+    puts 'Master not running'
+  end
+ensure
+  zk.close()
+end
+

bin/hbase-jruby

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+#!/bin/bash
+
+`dirname $0`/hbase org.jruby.Main $*
+