001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache license, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the license for the specific language governing permissions and
015 * limitations under the license.
016 */
017package org.apache.logging.log4j.core.async;
018
019import java.util.Arrays;
020import java.util.List;
021
022import org.apache.logging.log4j.Level;
023import org.apache.logging.log4j.LogManager;
024import org.apache.logging.log4j.core.Filter;
025import org.apache.logging.log4j.core.LogEvent;
026import org.apache.logging.log4j.core.config.AppenderRef;
027import org.apache.logging.log4j.core.config.Configuration;
028import org.apache.logging.log4j.core.config.LoggerConfig;
029import org.apache.logging.log4j.core.config.Node;
030import org.apache.logging.log4j.core.config.Property;
031import org.apache.logging.log4j.core.config.plugins.Plugin;
032import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
033import org.apache.logging.log4j.core.config.plugins.PluginConfiguration;
034import org.apache.logging.log4j.core.config.plugins.PluginElement;
035import org.apache.logging.log4j.core.config.plugins.PluginFactory;
036import org.apache.logging.log4j.core.jmx.RingBufferAdmin;
037import org.apache.logging.log4j.core.util.Booleans;
038import org.apache.logging.log4j.util.Strings;
039
040/**
041 * Asynchronous Logger object that is created via configuration and can be
042 * combined with synchronous loggers.
043 * <p>
044 * AsyncLoggerConfig is a logger designed for high throughput and low latency
045 * logging. It does not perform any I/O in the calling (application) thread, but
046 * instead hands off the work to another thread as soon as possible. The actual
047 * logging is performed in the background thread. It uses the LMAX Disruptor
048 * library for inter-thread communication. (<a
049 * href="http://lmax-exchange.github.com/disruptor/"
050 * >http://lmax-exchange.github.com/disruptor/</a>)
051 * <p>
052 * To use AsyncLoggerConfig, specify {@code <asyncLogger>} or
053 * {@code <asyncRoot>} in configuration.
054 * <p>
055 * Note that for performance reasons, this logger does not include source
056 * location by default. You need to specify {@code includeLocation="true"} in
057 * the configuration or any %class, %location or %line conversion patterns in
058 * your log4j.xml configuration will produce either a "?" character or no output
059 * at all.
060 * <p>
061 * For best performance, use AsyncLoggerConfig with the RandomAccessFileAppender or
062 * RollingRandomAccessFileAppender, with immediateFlush=false. These appenders have
063 * built-in support for the batching mechanism used by the Disruptor library,
064 * and they will flush to disk at the end of each batch. This means that even
065 * with immediateFlush=false, there will never be any items left in the buffer;
066 * all log events will all be written to disk in a very efficient manner.
067 */
068@Plugin(name = "asyncLogger", category = Node.CATEGORY, printObject = true)
069public class AsyncLoggerConfig extends LoggerConfig {
070
071    private final AsyncLoggerConfigDelegate delegate;
072
073    protected AsyncLoggerConfig(final String name,
074            final List<AppenderRef> appenders, final Filter filter,
075            final Level level, final boolean additive,
076            final Property[] properties, final Configuration config,
077            final boolean includeLocation) {
078        super(name, appenders, filter, level, additive, properties, config,
079                includeLocation);
080        delegate = config.getAsyncLoggerConfigDelegate();
081        delegate.setLogEventFactory(getLogEventFactory());
082    }
083
084    /**
085     * Passes on the event to a separate thread that will call
086     * {@link #asyncCallAppenders(LogEvent)}.
087     */
088    @Override
089    protected void callAppenders(final LogEvent event) {
090        populateLazilyInitializedFields(event);
091
092        if (!delegate.tryEnqueue(event, this)) {
093            final EventRoute eventRoute = delegate.getEventRoute(event.getLevel());
094            eventRoute.logMessage(this, event);
095        }
096    }
097
098    private void populateLazilyInitializedFields(final LogEvent event) {
099        event.getSource();
100        event.getThreadName();
101    }
102
103    void callAppendersInCurrentThread(final LogEvent event) {
104        super.callAppenders(event);
105    }
106
107    void callAppendersInBackgroundThread(final LogEvent event) {
108        delegate.enqueueEvent(event, this);
109    }
110
111    /** Called by AsyncLoggerConfigHelper.RingBufferLog4jEventHandler. */
112    void asyncCallAppenders(final LogEvent event) {
113        super.callAppenders(event);
114    }
115
116    private String displayName() {
117        return LogManager.ROOT_LOGGER_NAME.equals(getName()) ? LoggerConfig.ROOT : getName();
118    }
119
120    @Override
121    public void start() {
122        LOGGER.trace("AsyncLoggerConfig[{}] starting...", displayName());
123        super.start();
124    }
125
126    @Override
127    public void stop() {
128        LOGGER.trace("AsyncLoggerConfig[{}] stopping...", displayName());
129        super.stop();
130    }
131
132    /**
133     * Creates and returns a new {@code RingBufferAdmin} that instruments the
134     * ringbuffer of this {@code AsyncLoggerConfig}.
135     *
136     * @param contextName name of the {@code LoggerContext}
137     * @return a new {@code RingBufferAdmin} that instruments the ringbuffer
138     */
139    public RingBufferAdmin createRingBufferAdmin(final String contextName) {
140        return delegate.createRingBufferAdmin(contextName, getName());
141    }
142
143    /**
144     * Factory method to create a LoggerConfig.
145     *
146     * @param additivity True if additive, false otherwise.
147     * @param levelName The Level to be associated with the Logger.
148     * @param loggerName The name of the Logger.
149     * @param includeLocation "true" if location should be passed downstream
150     * @param refs An array of Appender names.
151     * @param properties Properties to pass to the Logger.
152     * @param config The Configuration.
153     * @param filter A Filter.
154     * @return A new LoggerConfig.
155     */
156    @PluginFactory
157    public static LoggerConfig createLogger(
158            @PluginAttribute("additivity") final String additivity,
159            @PluginAttribute("level") final String levelName,
160            @PluginAttribute("name") final String loggerName,
161            @PluginAttribute("includeLocation") final String includeLocation,
162            @PluginElement("AppenderRef") final AppenderRef[] refs,
163            @PluginElement("Properties") final Property[] properties,
164            @PluginConfiguration final Configuration config,
165            @PluginElement("Filter") final Filter filter) {
166        if (loggerName == null) {
167            LOGGER.error("Loggers cannot be configured without a name");
168            return null;
169        }
170
171        final List<AppenderRef> appenderRefs = Arrays.asList(refs);
172        Level level;
173        try {
174            level = Level.toLevel(levelName, Level.ERROR);
175        } catch (final Exception ex) {
176            LOGGER.error(
177                    "Invalid Log level specified: {}. Defaulting to Error",
178                    levelName);
179            level = Level.ERROR;
180        }
181        final String name = loggerName.equals(LoggerConfig.ROOT) ? Strings.EMPTY : loggerName;
182        final boolean additive = Booleans.parseBoolean(additivity, true);
183
184        return new AsyncLoggerConfig(name, appenderRefs, filter, level,
185                additive, properties, config, includeLocation(includeLocation));
186    }
187
188    // Note: for asynchronous loggers, includeLocation default is FALSE
189    protected static boolean includeLocation(final String includeLocationConfigValue) {
190        return Boolean.parseBoolean(includeLocationConfigValue);
191    }
192
193    /**
194     * An asynchronous root Logger.
195     */
196    @Plugin(name = "asyncRoot", category = "Core", printObject = true)
197    public static class RootLogger extends LoggerConfig {
198
199        @PluginFactory
200        public static LoggerConfig createLogger(
201                @PluginAttribute("additivity") final String additivity,
202                @PluginAttribute("level") final String levelName,
203                @PluginAttribute("includeLocation") final String includeLocation,
204                @PluginElement("AppenderRef") final AppenderRef[] refs,
205                @PluginElement("Properties") final Property[] properties,
206                @PluginConfiguration final Configuration config,
207                @PluginElement("Filter") final Filter filter) {
208            final List<AppenderRef> appenderRefs = Arrays.asList(refs);
209            Level level;
210            try {
211                level = Level.toLevel(levelName, Level.ERROR);
212            } catch (final Exception ex) {
213                LOGGER.error(
214                        "Invalid Log level specified: {}. Defaulting to Error",
215                        levelName);
216                level = Level.ERROR;
217            }
218            final boolean additive = Booleans.parseBoolean(additivity, true);
219
220            return new AsyncLoggerConfig(LogManager.ROOT_LOGGER_NAME,
221                    appenderRefs, filter, level, additive, properties, config,
222                    AsyncLoggerConfig.includeLocation(includeLocation));
223        }
224    }
225}