/**
* 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.
*/
package org.apache.hadoop.fs.azure.metrics;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.metrics2.MetricsSource;
import org.apache.hadoop.metrics2.impl.MetricsSystemImpl;
/**
* AzureFileSystemMetricsSystem
*/
@InterfaceAudience.Private
public final class AzureFileSystemMetricsSystem {
private static MetricsSystemImpl instance;
private static int numFileSystems;
//private ctor
private AzureFileSystemMetricsSystem(){
}
public static synchronized void fileSystemStarted() {
if (numFileSystems == 0) {
instance = new MetricsSystemImpl();
instance.init("azure-file-system");
}
numFileSystems++;
}
public static synchronized void fileSystemClosed() {
if (numFileSystems == 1) {
instance.publishMetricsNow();
instance.stop();
instance.shutdown();
instance = null;
}
numFileSystems--;
}
public static void registerSource(String name, String desc,
MetricsSource source) {
//caller has to use unique name to register source
instance.register(name, desc, source);
}
public static synchronized void unregisterSource(String name) {
if (instance != null) {
//publish metrics before unregister a metrics source
instance.publishMetricsNow();
instance.unregisterSource(name);
}
}
}