HBASE-29033 Add a shell command for inspecting the state of enable/di…

hbase-shell/src/main/ruby/hbase/quotas.rb

@@ -366,6 +366,10 @@ def switch_rpc_throttle(enabled)
       @admin.switchRpcThrottle(java.lang.Boolean.valueOf(enabled))
     end
 
+    def is_rpc_throttle_enabled()
+      @admin.isRpcThrottleEnabled()
+    end
+
     def switch_exceed_throttle_quota(enabled)
       @admin.exceedThrottleQuotaSwitch(java.lang.Boolean.valueOf(enabled))
     end

hbase-shell/src/main/ruby/shell.rb

@@ -576,6 +576,7 @@ def self.exception_handler(hide_traceback)
     list_snapshot_sizes
     enable_rpc_throttle
     disable_rpc_throttle
+    rpc_throttle_enabled
     enable_exceed_throttle_quota
     disable_exceed_throttle_quota
   ]

hbase-shell/src/main/ruby/shell/commands/rpc_throttle_enabled.rb

@@ -0,0 +1,41 @@
+#
+#
+# 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.
+#
+
+
+module Shell
+  module Commands
+    class RpcThrottleEnabled < Command
+      def help
+        <<-EOF
+Query the current rpc throttle state.
+Returns true if rpc throttle is enabled, false otherwise.
+
+Examples:
+  hbase> rpc_throttle_enabled
+EOF
+      end
+
+      def command
+        state = !!quotas_admin.is_rpc_throttle_enabled
+        formatter.row(["Rpc throttle enabled : #{state}"])
+        state
+      end
+    end
+  end
+end

hbase-shell/src/test/ruby/hbase/quotas_test.rb

@@ -245,15 +245,30 @@ def teardown
     end
 
     define_test 'switch rpc throttle' do
+      result = nil
+      output = capture_stdout { result = command(:rpc_throttle_enabled) }
+      assert(output.include?('Rpc throttle enabled : true'))
+      assert(result == true)
+
       result = nil
       output = capture_stdout { result = command(:disable_rpc_throttle) }
       assert(output.include?('Previous rpc throttle state : true'))
       assert(result == true)
 
+      result = nil
+      output = capture_stdout { result = command(:rpc_throttle_enabled) }
+      assert(output.include?('Rpc throttle enabled : false'))
+      assert(result == false)
+
       result = nil
       output = capture_stdout { result = command(:enable_rpc_throttle) }
       assert(output.include?('Previous rpc throttle state : false'))
       assert(result == false)
+
+      result = nil
+      output = capture_stdout { result = command(:rpc_throttle_enabled) }
+      assert(output.include?('Rpc throttle enabled : true'))
+      assert(result == true)
     end
 
     define_test 'can set and remove region server quota' do