JmxMetricPoller.java
/**
* Copyright 2013 Netflix, Inc.
* <p/>
* Licensed 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
* <p/>
* http://www.apache.org/licenses/LICENSE-2.0
* <p/>
* 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 com.netflix.servo.publish;
import com.netflix.servo.Metric;
import com.netflix.servo.annotations.DataSourceType;
import com.netflix.servo.monitor.MonitorConfig;
import com.netflix.servo.tag.BasicTagList;
import com.netflix.servo.tag.SmallTagMap;
import com.netflix.servo.tag.StandardTagKeys;
import com.netflix.servo.tag.Tag;
import com.netflix.servo.tag.TagList;
import com.netflix.servo.tag.Tags;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.management.Attribute;
import javax.management.InstanceNotFoundException;
import javax.management.JMException;
import javax.management.MBeanAttributeInfo;
import javax.management.MBeanInfo;
import javax.management.MBeanServerConnection;
import javax.management.ObjectName;
import javax.management.ReflectionException;
import javax.management.openmbean.CompositeData;
import javax.management.openmbean.TabularData;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* Generic poller for fetching simple data from JMX.
*/
public final class JmxMetricPoller implements MetricPoller {
private static final Logger LOGGER =
LoggerFactory.getLogger(JmxMetricPoller.class);
private static final Tag CLASS_TAG = Tags.newTag(
StandardTagKeys.CLASS_NAME.getKeyName(),
JmxMetricPoller.class.getCanonicalName());
private static final String DOMAIN_KEY = "JmxDomain";
private static final String COMPOSITE_PATH_KEY = "JmxCompositePath";
private static final String PROP_KEY_PREFIX = "Jmx";
private final JmxConnector connector;
private final List<ObjectName> queries;
private final MetricFilter counters;
private final boolean onlyNumericMetrics;
private final List<Tag> defaultTags;
/**
* Creates a new instance that polls mbeans matching the provided object
* name pattern.
*
* @param connector used to get a connection to an MBeanServer
* @param query object name pattern for selecting mbeans
* @param counters metrics matching this filter will be treated as
* counters, all others will be gauges
*/
public JmxMetricPoller(
JmxConnector connector, ObjectName query, MetricFilter counters) {
this(connector, Collections.singletonList(query), counters, true, null);
}
/**
* Creates a new instance that polls mbeans matching the provided object
* name patterns.
*
* @param connector used to get a connection to an MBeanServer
* @param queries object name patterns for selecting mbeans
* @param counters metrics matching this filter will be treated as
* counters, all others will be gauges
*/
public JmxMetricPoller(
JmxConnector connector, List<ObjectName> queries, MetricFilter counters) {
this(connector, queries, counters, true, null);
}
/**
* Creates a new instance that polls mbeans matching the provided object
* name pattern.
*
* @param connector used to get a connection to an MBeanServer
* @param queries object name patterns for selecting mbeans
* @param counters metrics matching this filter will be treated as
* counters, all others will be gauges
* @param onlyNumericMetrics only produce metrics that can be converted to a Number
* (filter out all strings, etc)
* @param defaultTags a list of tags to attach to all metrics, usually
* useful to identify all metrics from a given application or hostname
*/
public JmxMetricPoller(
JmxConnector connector, List<ObjectName> queries, MetricFilter counters,
boolean onlyNumericMetrics, List<Tag> defaultTags) {
this.connector = connector;
this.queries = queries;
this.counters = counters;
this.onlyNumericMetrics = onlyNumericMetrics;
this.defaultTags = defaultTags;
}
/**
* Creates a tag list from an object name.
*/
private TagList createTagList(ObjectName name) {
Map<String, String> props = name.getKeyPropertyList();
SmallTagMap.Builder tagsBuilder = SmallTagMap.builder();
for (Map.Entry<String, String> e : props.entrySet()) {
String key = PROP_KEY_PREFIX + "." + e.getKey();
tagsBuilder.add(Tags.newTag(key, e.getValue()));
}
tagsBuilder.add(Tags.newTag(DOMAIN_KEY, name.getDomain()));
tagsBuilder.add(CLASS_TAG);
if (defaultTags != null) {
defaultTags.forEach(tagsBuilder::add);
}
return new BasicTagList(tagsBuilder.result());
}
private static TagList getTagListWithAdditionalTag(TagList tags, Tag extra) {
return new BasicTagList(SmallTagMap.builder().addAll(tags).add(extra).result());
}
/**
* Create a new metric object and add it to the list.
*/
private void addMetric(
List<Metric> metrics,
String name,
TagList tags,
Object value) {
long now = System.currentTimeMillis();
if (onlyNumericMetrics) {
value = asNumber(value);
}
if (value != null) {
TagList newTags = counters.matches(MonitorConfig.builder(name).withTags(tags).build())
? getTagListWithAdditionalTag(tags, DataSourceType.COUNTER)
: getTagListWithAdditionalTag(tags, DataSourceType.GAUGE);
Metric m = new Metric(name, newTags, now, value);
metrics.add(m);
}
}
/**
* Recursively extracts simple numeric values from composite data objects.
* The map {@code values} will be populated with a path to the value as
* the key and the simple object as the value.
*/
private void extractValues(String path, Map<String, Object> values, CompositeData obj) {
for (String key : obj.getCompositeType().keySet()) {
String newPath = (path == null) ? key : path + "." + key;
Object value = obj.get(key);
if (value instanceof CompositeData) {
extractValues(newPath, values, (CompositeData) value);
} else if (value != null) {
values.put(newPath, value);
}
}
}
/**
* Query the mbean connection and add all metrics that satisfy the filter
* to the list {@code metrics}.
*/
private void getMetrics(
MBeanServerConnection con,
MetricFilter filter,
List<Metric> metrics,
ObjectName name)
throws JMException, IOException {
// Create tags from the object name
TagList tags = createTagList(name);
MBeanInfo info = con.getMBeanInfo(name);
MBeanAttributeInfo[] attrInfos = info.getAttributes();
// Restrict to attributes that match the filter
List<String> matchingNames = new ArrayList<>();
for (MBeanAttributeInfo attrInfo : attrInfos) {
String attrName = attrInfo.getName();
if (filter.matches(new MonitorConfig.Builder(attrName).withTags(tags).build())) {
matchingNames.add(attrName);
}
}
List<Attribute> attributeList = safelyLoadAttributes(con, name, matchingNames);
for (Attribute attr : attributeList) {
String attrName = attr.getName();
Object obj = attr.getValue();
if (obj instanceof TabularData) {
((TabularData) obj).values().stream()
.filter(key -> key instanceof CompositeData)
.forEach(key -> addTabularMetrics(filter, metrics, tags, attrName,
(CompositeData) key));
} else if (obj instanceof CompositeData) {
addCompositeMetrics(filter, metrics, tags, attrName, (CompositeData) obj);
} else {
addMetric(metrics, attrName, tags, obj);
}
}
}
private void addCompositeMetrics(MetricFilter filter, List<Metric> metrics, TagList tags,
String attrName, CompositeData obj) {
Map<String, Object> values = new HashMap<>();
extractValues(null, values, obj);
for (Map.Entry<String, Object> e : values.entrySet()) {
final Tag compositeTag = Tags.newTag(COMPOSITE_PATH_KEY, e.getKey());
final TagList newTags = getTagListWithAdditionalTag(tags, compositeTag);
if (filter.matches(MonitorConfig.builder(attrName).withTags(newTags).build())) {
addMetric(metrics, attrName, newTags, e.getValue());
}
}
}
private void addTabularMetrics(MetricFilter filter, List<Metric> metrics, TagList tags,
String attrName, CompositeData obj) {
Map<String, Object> values = new HashMap<>();
// tabular composite data has a value called key and one called value
values.put(obj.get("key").toString(), obj.get("value"));
for (Map.Entry<String, Object> e : values.entrySet()) {
final Tag compositeTag = Tags.newTag(COMPOSITE_PATH_KEY, e.getKey());
final TagList newTags = getTagListWithAdditionalTag(tags, compositeTag);
if (filter.matches(MonitorConfig.builder(attrName).withTags(newTags).build())) {
addMetric(metrics, attrName, newTags, e.getValue());
}
}
}
/**
* Try to convert an object into a number. Boolean values will return 1 if
* true and 0 if false. If the value is null or an unknown data type null
* will be returned.
*/
private static Number asNumber(Object value) {
Number num = null;
if (value == null) {
num = null;
} else if (value instanceof Number) {
num = (Number) value;
} else if (value instanceof Boolean) {
num = ((Boolean) value) ? 1 : 0;
}
return num;
}
/**
* {@inheritDoc}
*/
public List<Metric> poll(MetricFilter filter) {
return poll(filter, false);
}
/**
* {@inheritDoc}
*/
public List<Metric> poll(MetricFilter filter, boolean reset) {
List<Metric> metrics = new ArrayList<>();
try {
MBeanServerConnection con = connector.getConnection();
for (ObjectName query : queries) {
Set<ObjectName> names = con.queryNames(query, null);
if (names.isEmpty()) {
LOGGER.warn("no mbeans matched query: {}", query);
} else {
for (ObjectName name : names) {
try {
getMetrics(con, filter, metrics, name);
} catch (Exception e) {
LOGGER.warn("failed to get metrics for: {}", name, e);
}
}
}
}
} catch (Exception e) {
LOGGER.warn("failed to collect jmx metrics.", e);
}
return metrics;
}
/**
* There are issues loading some JMX attributes on some systems. This protects us from a
* single bad attribute stopping us reading any metrics (or just a random sampling) out of
* the system.
*/
private static List<Attribute> safelyLoadAttributes(
MBeanServerConnection server, ObjectName objectName, List<String> matchingNames) {
try {
// first try batch loading all attributes as this is faster
return batchLoadAttributes(server, objectName, matchingNames);
} catch (Exception e) {
// JBOSS ticket: https://issues.jboss.org/browse/AS7-4404
LOGGER.info("Error batch loading attributes for {} : {}", objectName, e.getMessage());
// some containers (jboss I am looking at you) fail the entire getAttributes request
// if one is broken we can get the working attributes if we ask for them individually
return individuallyLoadAttributes(server, objectName, matchingNames);
}
}
private static List<Attribute> batchLoadAttributes(
MBeanServerConnection server, ObjectName objectName, List<String> matchingNames)
throws InstanceNotFoundException, ReflectionException, IOException {
final String[] namesArray = matchingNames.toArray(new String[matchingNames.size()]);
return server.getAttributes(objectName, namesArray).asList();
}
private static List<Attribute> individuallyLoadAttributes(
MBeanServerConnection server, ObjectName objectName, List<String> matchingNames) {
List<Attribute> attributes = new ArrayList<>();
for (String attrName : matchingNames) {
try {
Object value = server.getAttribute(objectName, attrName);
attributes.add(new Attribute(attrName, value));
} catch (Exception e) {
LOGGER.info("Couldn't load attribute {} for {} : {}",
new Object[]{attrName, objectName, e.getMessage()}, e);
}
}
return attributes;
}
}