/**
* Copyright 2010 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.
*/
package org.apache.hadoop.hbase.metrics;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.management.AttributeNotFoundException;
import javax.management.MBeanAttributeInfo;
import javax.management.MBeanException;
import javax.management.MBeanInfo;
import javax.management.ReflectionException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.metrics.util.MetricsBase;
import org.apache.hadoop.metrics.util.MetricsDynamicMBeanBase;
import org.apache.hadoop.metrics.util.MetricsRegistry;
/**
* Extends the Hadoop MetricsDynamicMBeanBase class to provide JMX support for
* custom HBase MetricsBase implementations. MetricsDynamicMBeanBase ignores
* registered MetricsBase instance that are not instances of one of the
* org.apache.hadoop.metrics.util implementations.
*
*/
public class MetricsMBeanBase extends MetricsDynamicMBeanBase {
private static final Log LOG = LogFactory.getLog("org.apache.hadoop.hbase.metrics");
protected final MetricsRegistry registry;
protected final String description;
protected int registryLength;
/** HBase MetricsBase implementations that MetricsDynamicMBeanBase does
* not understand
*/
protected Map<String,MetricsBase> extendedAttributes =
new HashMap<String,MetricsBase>();
protected MBeanInfo extendedInfo;
protected MetricsMBeanBase( MetricsRegistry mr, String description ) {
super(copyMinusHBaseMetrics(mr), description);
this.registry = mr;
this.description = description;
this.init();
}
/*
* @param mr MetricsRegistry.
* @return A copy of the passed MetricsRegistry minus the hbase metrics
*/
private static MetricsRegistry copyMinusHBaseMetrics(final MetricsRegistry mr) {
MetricsRegistry copy = new MetricsRegistry();
for (MetricsBase metric : mr.getMetricsList()) {
if (metric instanceof MetricsRate || metric instanceof MetricsString) {
continue;
}
copy.add(metric.getName(), metric);
}
return copy;
}
protected void init() {
List<MBeanAttributeInfo> attributes = new ArrayList<MBeanAttributeInfo>();
MBeanInfo parentInfo = super.getMBeanInfo();
List<String> parentAttributes = new ArrayList<String>();
for (MBeanAttributeInfo attr : parentInfo.getAttributes()) {
attributes.add(attr);
parentAttributes.add(attr.getName());
}
this.registryLength = this.registry.getMetricsList().size();
for (MetricsBase metric : this.registry.getMetricsList()) {
if (metric.getName() == null || parentAttributes.contains(metric.getName()))
continue;
// add on custom HBase metric types
if (metric instanceof MetricsRate) {
attributes.add( new MBeanAttributeInfo(metric.getName(),
"java.lang.Float", metric.getDescription(), true, false, false) );
extendedAttributes.put(metric.getName(), metric);
} else if (metric instanceof MetricsString) {
attributes.add( new MBeanAttributeInfo(metric.getName(),
"java.lang.String", metric.getDescription(), true, false, false) );
extendedAttributes.put(metric.getName(), metric);
LOG.info("MetricsString added: " + metric.getName());
}
// else, its probably a hadoop metric already registered. Skip it.
}
LOG.info("new MBeanInfo");
this.extendedInfo = new MBeanInfo( this.getClass().getName(),
this.description, attributes.toArray( new MBeanAttributeInfo[0] ),
parentInfo.getConstructors(), parentInfo.getOperations(),
parentInfo.getNotifications() );
}
private void checkAndUpdateAttributes() {
if (this.registryLength != this.registry.getMetricsList().size())
this.init();
}
@Override
public Object getAttribute( String name )
throws AttributeNotFoundException, MBeanException,
ReflectionException {
if (name == null) {
throw new IllegalArgumentException("Attribute name is NULL");
}
/*
* Ugly. Since MetricsDynamicMBeanBase implementation is private,
* we need to first check the parent class for the attribute.
* In case that the MetricsRegistry contents have changed, this will
* allow the parent to update it's internal structures (which we rely on
* to update our own.
*/
try {
return super.getAttribute(name);
} catch (AttributeNotFoundException ex) {
checkAndUpdateAttributes();
MetricsBase metric = this.extendedAttributes.get(name);
if (metric != null) {
if (metric instanceof MetricsRate) {
return ((MetricsRate) metric).getPreviousIntervalValue();
} else if (metric instanceof MetricsString) {
return ((MetricsString)metric).getValue();
} else {
LOG.warn( String.format("unknown metrics type %s for attribute %s",
metric.getClass().getName(), name) );
}
}
}
throw new AttributeNotFoundException();
}
@Override
public MBeanInfo getMBeanInfo() {
return this.extendedInfo;
}
}