/*
* 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.mapred;
import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.regex.Pattern;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.mapreduce.server.jobtracker.TaskTracker;
import org.apache.hadoop.metrics.MetricsContext;
import org.apache.hadoop.metrics.MetricsRecord;
import org.apache.hadoop.metrics.MetricsUtil;
import org.apache.hadoop.metrics.Updater;
import org.apache.hadoop.metrics.util.MetricsBase;
import org.apache.hadoop.metrics.util.MetricsRegistry;
import org.apache.hadoop.metrics.util.MetricsTimeVaryingLong;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;
import org.xml.sax.SAXException;
public class TaskErrorCollector implements Updater {
private static final String ERROR_XML = "error.xml";
public static final String NUM_WINDOWS_KEY = "mapred.taskerrorcollector.window.number";
public static final String WINDOW_LENGTH_KEY = "mapred.taskerrorcollector.window.milliseconds";
public static final String CONFIG_FILE_KEY = "mapred.taskerrorcollector.error.file";
public static final String COUNTER_GROUP_NAME = "TaskError";
public static final Log LOG = LogFactory.getLog(TaskErrorCollector.class);
private static final String METRICS_KEY_PREFIX = "task_error_";
private final MetricsRecord metricsRecord;
private final MetricsRegistry registry;
private final Map<String, TaskError> knownErrors;
private final TaskError UNKNOWN_ERROR = new TaskError("UNKNOWN", "",
"Task diagnostic info does not match any pattern defined in xml file");
// Used by UI
static final private int WINDOW_LENGTH = 10 * 60 * 1000; // 10 minute
static final private int NUM_WINDOWS = 3 * 86400 * 1000 / WINDOW_LENGTH; // 3 days
private long lastWindowIndex = 0;
private final int windowLength;
private final int numWindows;
private final LinkedList<Map<TaskError, Integer>> errorCountsQueue =
new LinkedList<Map<TaskError, Integer>>();
private final LinkedList<Long> startTimeQueue = new LinkedList<Long>();
private final Map<TaskError, Integer> sinceStartErrorCounts;
// Used by metrics
private final Map<TaskError, MetricsTimeVaryingLong> errorCountsMetrics =
new HashMap<TaskError, MetricsTimeVaryingLong>();
// Cumulative counters
private final Counters errorCounters = new Counters();
public TaskErrorCollector(Configuration conf) {
this(
conf,
conf.getInt(WINDOW_LENGTH_KEY, WINDOW_LENGTH),
conf.getInt(NUM_WINDOWS_KEY, NUM_WINDOWS));
}
public TaskErrorCollector(
Configuration conf, int windowLength, int numWindows) {
this.windowLength = windowLength;
this.numWindows = numWindows;
MetricsContext context = MetricsUtil.getContext("mapred");
metricsRecord = MetricsUtil.createRecord(context, "taskerror");
registry = new MetricsRegistry();
context.registerUpdater(this);
URL configURL = null;
String configFilePath = conf.get(CONFIG_FILE_KEY);
if (configFilePath == null) {
// Search the class path if it is not configured
configURL =
TaskErrorCollector.class.getClassLoader().getResource(ERROR_XML);
} else {
try {
configURL = new URL("file://" +
new File(configFilePath).getAbsolutePath());
} catch (MalformedURLException e) {
LOG.error("Error in creating config URL", e);
}
}
if (configURL == null) {
LOG.warn("Could not get error collector configuration. " +
TaskErrorCollector.class.getSimpleName() +
" will see every error as UNKNOWN_ERROR.");
knownErrors = Collections.emptyMap();
} else {
LOG.info("Parsing configuration from " + configURL);
knownErrors = parseConfigFile(configURL);
}
createMetrics();
sinceStartErrorCounts = createErrorCountsMap();
}
private void createMetrics() {
for (TaskError error : knownErrors.values()) {
LOG.info("metricsKey:" + error.metricsKey);
errorCountsMetrics.put(error, new MetricsTimeVaryingLong(
error.metricsKey, registry, error.description));
}
errorCountsMetrics.put(UNKNOWN_ERROR, new MetricsTimeVaryingLong(
UNKNOWN_ERROR.metricsKey, registry, UNKNOWN_ERROR.description));
}
private Map<TaskError, Integer> createErrorCountsMap() {
Map<TaskError, Integer> errorCountsMap =
new LinkedHashMap<TaskError, Integer>();
Counters.Group grp = errorCounters.getGroup(COUNTER_GROUP_NAME);
for (TaskError error : knownErrors.values()) {
errorCountsMap.put(error, 0);
// Make sure counter is present with value 0.
grp.getCounterForName(error.name).increment(0);
}
errorCountsMap.put(UNKNOWN_ERROR, 0);
return errorCountsMap;
}
public synchronized void collect(TaskInProgress tip, TaskAttemptID taskId,
long now) {
List<String> diagnostics = tip.getDiagnosticInfo(taskId);
if (diagnostics == null || diagnostics.isEmpty()) {
incErrorCounts(UNKNOWN_ERROR, now);
return;
}
String latestDiagnostic = diagnostics.get(diagnostics.size() - 1);
latestDiagnostic = latestDiagnostic.replace("\n", " ");
boolean found = false;
for (TaskError error : knownErrors.values()) {
String p = error.pattern.toString();
if (error.pattern.matcher(latestDiagnostic).matches()) {
incErrorCounts(error, now);
found = true;
break;
}
}
if (!found) {
LOG.info("Undefined diagnostic info:" + latestDiagnostic);
incErrorCounts(UNKNOWN_ERROR, now);
}
}
/**
*/
/**
* Get recent TaskError counts within the given window
* @param timeWindow Window size in milliseconds.
* Ex: 24 * 60 * 60 * 1000 gives you last day error counts
* @return Counts for each TaskError
*/
public synchronized Map<TaskError, Integer> getRecentErrorCounts(long timeWindow) {
long start = System.currentTimeMillis() - timeWindow;
Map<TaskError, Integer> errorCounts = createErrorCountsMap();
Iterator<Map<TaskError, Integer>> errorCountsIter = errorCountsQueue.iterator();
Iterator<Long> startTimeIter = startTimeQueue.iterator();
while (errorCountsIter.hasNext() && start < startTimeIter.next()) {
Map<TaskError, Integer> windowErrorCounts = errorCountsIter.next();
for (Map.Entry<TaskError, Integer> entry : windowErrorCounts.entrySet()) {
errorCounts.put(entry.getKey(),
errorCounts.get(entry.getKey()) + entry.getValue());
}
}
return errorCounts;
}
public synchronized Map<TaskError, Integer> getErrorCounts() {
return Collections.unmodifiableMap(sinceStartErrorCounts);
}
private void incErrorCounts(TaskError error, long now) {
Map<TaskError, Integer> current = getCurrentErrorCounts(now);
current.put(error, current.get(error) + 1);
errorCountsMetrics.get(error).inc();
Counters.Group grp = errorCounters.getGroup(COUNTER_GROUP_NAME);
Counters.Counter ctr = grp.getCounterForName(error.name);
ctr.increment(1);
sinceStartErrorCounts.put(error, sinceStartErrorCounts.get(error) + 1);
}
private Map<TaskError, Integer> getCurrentErrorCounts(long now) {
long windowIndex = now / windowLength;
if (windowIndex != lastWindowIndex || errorCountsQueue.isEmpty()) {
lastWindowIndex = windowIndex;
errorCountsQueue.addFirst(createErrorCountsMap());
startTimeQueue.addFirst(windowIndex * windowLength);
if (errorCountsQueue.size() > numWindows) {
errorCountsQueue.removeLast();
startTimeQueue.removeLast();
}
}
return errorCountsQueue.getFirst();
}
public Counters getErrorCountsCounters() {
return errorCounters;
}
public class TaskError {
final String name;
final Pattern pattern;
final String metricsKey;
final String description;
TaskError(String name, String patternString, String description) {
this.name = name;
this.metricsKey = toMetricName(name);
this.pattern = Pattern.compile(patternString);
this.description = description;
}
private String toMetricName(String name) {
return METRICS_KEY_PREFIX + name.toLowerCase().replaceAll("\\s+", "_");
}
@Override
public String toString() {
return "name:" + name + " pattern:" + pattern.toString() +
" metricsKey:" + metricsKey + " description:" + description;
}
}
@Override
public void doUpdates(MetricsContext context) {
synchronized (this) {
for (MetricsBase m : registry.getMetricsList()) {
m.pushMetric(metricsRecord);
}
}
metricsRecord.update();
}
/**
* Parse the error.xml file which contains the error
*
* The following is an example of the error.xml
*
* <?xml version="1.0"?>
* <configuration>
* <error name="Map output lost">
* <pattern>Map output lost</pattern>
* <description>TaskTracker cannot find requested map output</description>
* </error>
* <error name="Memory killing">
* <pattern>Killing the top memory-consuming tasks.*</pattern>
* <description>When TaskTracker has no enough memory, it kills the task with highest memory</description>
* </error>
* <error name="Memory failing">
* <pattern>Failing the top memory-consuming tasks.*</pattern>
* <description>When TaskTracker has no enough memory, it check the task with highest memory. If it used more than configured memory, the task fails.</description>
* </error>
* <error name="Preemption">
* <pattern>Killed for preemption.*</pattern>
* <description>Task killed because of preemption</description>
* </error>
* <error name="Killed from JSP">
* <pattern>Killed from JSP page.*</pattern>
* <description>Someone kill the task from Web UI</description>
* </error>
* <error name="No space">
* <pattern>No space left on device.*</pattern>
* <description>Cannot find disk space on the TaskTracker</description>
* </error>
* </configuration>
* @param configURL
* @throws IOException
*
*/
private Map<String, TaskError> parseConfigFile(URL configURL) {
Map<String, TaskError> knownErrors = new LinkedHashMap<String, TaskError>();
try {
Element root = getRootElement(configURL);
NodeList elements = root.getChildNodes();
for (int i = 0; i < elements.getLength(); ++i) {
Node node = elements.item(i);
if (!(node instanceof Element)) {
continue;
}
Element element = (Element)node;
if (matched(element, "error")) {
String name = element.getAttribute("name");
String pattern = "";
String description = "";
NodeList fields = element.getChildNodes();
for (int j = 0; j < fields.getLength(); ++j) {
Node fieldNode = fields.item(j);
if (!(fieldNode instanceof Element)) {
continue;
}
Element field = (Element)fieldNode;
if (matched(field, "pattern")) {
pattern = getText(field);
} else if (matched(field, "description")) {
description = getText(field);
}
}
TaskError taskError = new TaskError(name, pattern, description);
LOG.info("Adding TaskError " + taskError);
knownErrors.put(name, taskError);
}
}
} catch (IOException ie) {
LOG.error("Error parsing config file " + configURL, ie);
}
return knownErrors;
}
private Element getRootElement(URL configURL) throws IOException {
Element root = null;
try {
DocumentBuilderFactory docBuilderFactory =
DocumentBuilderFactory.newInstance();
docBuilderFactory.setIgnoringComments(true);
DocumentBuilder builder = docBuilderFactory.newDocumentBuilder();
Document doc = builder.parse(configURL.openStream());
root = doc.getDocumentElement();
if (!matched(root, "configuration")) {
throw new IOException("Bad task error config at " + configURL);
}
} catch (SAXException se) {
throw new IOException(se);
} catch (ParserConfigurationException pe) {
throw new IOException(pe);
}
return root;
}
private static boolean matched(Element element, String tagName) {
return tagName.equals(element.getTagName());
}
private static String getText(Element element) {
return ((Text)element.getFirstChild()).getData().trim();
}
}