/*
* 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.solr.metrics;
import javax.management.Attribute;
import javax.management.AttributeList;
import javax.management.AttributeNotFoundException;
import javax.management.DynamicMBean;
import javax.management.InvalidAttributeValueException;
import javax.management.MBeanAttributeInfo;
import javax.management.MBeanException;
import javax.management.MBeanInfo;
import javax.management.ReflectionException;
import javax.management.openmbean.OpenMBeanAttributeInfoSupport;
import javax.management.openmbean.OpenType;
import javax.management.openmbean.SimpleType;
import java.lang.invoke.MethodHandles;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.function.BiConsumer;
import com.codahale.metrics.Gauge;
import com.codahale.metrics.Metric;
import org.apache.lucene.store.AlreadyClosedException;
import org.apache.solr.common.SolrException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Dynamically constructed map of metrics, intentionally different from {@link com.codahale.metrics.MetricSet}
* where each metric had to be known in advance and registered separately in {@link com.codahale.metrics.MetricRegistry}.
* <p>Note: this awkwardly extends {@link Gauge} and not {@link Metric} because awkwardly {@link Metric} instances
* are not supported by {@link com.codahale.metrics.MetricRegistryListener} :(</p>
* <p>Note 2: values added to this metric map should belong to the list of types supported by JMX:
* {@link javax.management.openmbean.OpenType#ALLOWED_CLASSNAMES_LIST}, otherwise only their toString()
* representation will be shown in JConsole.</p>
*/
public class MetricsMap implements Gauge<Map<String,Object>>, DynamicMBean {
private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
// set to true to use cached statistics between getMBeanInfo calls to work
// around over calling getStatistics on MBeanInfos when iterating over all attributes (SOLR-6586)
private final boolean useCachedStatsBetweenGetMBeanInfoCalls = Boolean.getBoolean("useCachedStatsBetweenGetMBeanInfoCalls");
private BiConsumer<Boolean, Map<String, Object>> initializer;
private volatile Map<String,Object> cachedValue;
public MetricsMap(BiConsumer<Boolean, Map<String,Object>> initializer) {
this.initializer = initializer;
}
@Override
public Map<String,Object> getValue() {
return getValue(true);
}
public Map<String,Object> getValue(boolean detailed) {
Map<String,Object> map = new HashMap<>();
initializer.accept(detailed, map);
return map;
}
public String toString() {
return getValue().toString();
}
@Override
public Object getAttribute(String attribute) throws AttributeNotFoundException, MBeanException, ReflectionException {
Object val;
Map<String,Object> stats = null;
if (useCachedStatsBetweenGetMBeanInfoCalls) {
Map<String,Object> cachedStats = this.cachedValue;
if (cachedStats != null) {
stats = cachedStats;
}
}
if (stats == null) {
stats = getValue(true);
}
val = stats.get(attribute);
if (val != null) {
// It's String or one of the simple types, just return it as JMX suggests direct support for such types
for (String simpleTypeName : SimpleType.ALLOWED_CLASSNAMES_LIST) {
if (val.getClass().getName().equals(simpleTypeName)) {
return val;
}
}
// It's an arbitrary object which could be something complex and odd, return its toString, assuming that is
// a workable representation of the object
return val.toString();
}
return null;
}
@Override
public void setAttribute(Attribute attribute) throws AttributeNotFoundException, InvalidAttributeValueException, MBeanException, ReflectionException {
throw new UnsupportedOperationException("Operation not Supported");
}
@Override
public AttributeList getAttributes(String[] attributes) {
AttributeList list = new AttributeList();
for (String attribute : attributes) {
try {
list.add(new Attribute(attribute, getAttribute(attribute)));
} catch (Exception e) {
log.warn("Could not get attribute " + attribute);
}
}
return list;
}
@Override
public AttributeList setAttributes(AttributeList attributes) {
throw new UnsupportedOperationException("Operation not Supported");
}
@Override
public Object invoke(String actionName, Object[] params, String[] signature) throws MBeanException, ReflectionException {
throw new UnsupportedOperationException("Operation not Supported");
}
@Override
public MBeanInfo getMBeanInfo() {
ArrayList<MBeanAttributeInfo> attrInfoList = new ArrayList<>();
Map<String,Object> stats = getValue(true);
if (useCachedStatsBetweenGetMBeanInfoCalls) {
cachedValue = stats;
}
try {
stats.forEach((k, v) -> {
Class type = v.getClass();
OpenType typeBox = determineType(type);
if (type.equals(String.class) || typeBox == null) {
attrInfoList.add(new MBeanAttributeInfo(k, String.class.getName(),
null, true, false, false));
} else {
attrInfoList.add(new OpenMBeanAttributeInfoSupport(
k, k, typeBox, true, false, false));
}
});
} catch (Exception e) {
// don't log issue if the core is closing
if (!(SolrException.getRootCause(e) instanceof AlreadyClosedException))
log.warn("Could not get attributes of MetricsMap: {}", this, e);
}
MBeanAttributeInfo[] attrInfoArr = attrInfoList
.toArray(new MBeanAttributeInfo[attrInfoList.size()]);
return new MBeanInfo(getClass().getName(), "MetricsMap", attrInfoArr, null, null, null);
}
private OpenType determineType(Class type) {
try {
for (Field field : SimpleType.class.getFields()) {
if (field.getType().equals(SimpleType.class)) {
SimpleType candidate = (SimpleType) field.get(SimpleType.class);
if (candidate.getTypeName().equals(type.getName())) {
return candidate;
}
}
}
} catch (Exception e) {
throw new RuntimeException(e);
}
return null;
}
}