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 static final long serialVersionUID = 1L;
072
073    private AsyncLoggerConfigDelegate delegate;
074
075    protected AsyncLoggerConfig(final String name,
076            final List<AppenderRef> appenders, final Filter filter,
077            final Level level, final boolean additive,
078            final Property[] properties, final Configuration config,
079            final boolean includeLocation) {
080        super(name, appenders, filter, level, additive, properties, config,
081                includeLocation);
082        delegate = config.getAsyncLoggerConfigDelegate();
083    }
084
085    /**
086     * Passes on the event to a separate thread that will call
087     * {@link #asyncCallAppenders(LogEvent)}.
088     */
089    @Override
090    protected void callAppenders(final LogEvent event) {
091        // populate lazily initialized fields
092        event.getSource();
093        event.getThreadName();
094
095        // pass on the event to a separate thread
096        if (!delegate.tryCallAppendersInBackground(event, this)) {
097            super.callAppenders(event);
098        }
099    }
100
101    /** Called by AsyncLoggerConfigHelper.RingBufferLog4jEventHandler. */
102    void asyncCallAppenders(final LogEvent event) {
103        super.callAppenders(event);
104    }
105
106    private String displayName() {
107        return LogManager.ROOT_LOGGER_NAME.equals(getName()) ? LoggerConfig.ROOT : getName();
108    }
109
110    @Override
111    public void start() {
112        LOGGER.trace("AsyncLoggerConfig[{}] starting...", displayName());
113        super.start();
114    }
115
116    @Override
117    public void stop() {
118        LOGGER.trace("AsyncLoggerConfig[{}] stopping...", displayName());
119        super.stop();
120    }
121
122    /**
123     * Creates and returns a new {@code RingBufferAdmin} that instruments the
124     * ringbuffer of this {@code AsyncLoggerConfig}.
125     *
126     * @param contextName name of the {@code LoggerContext}
127     * @return a new {@code RingBufferAdmin} that instruments the ringbuffer
128     */
129    public RingBufferAdmin createRingBufferAdmin(final String contextName) {
130        return delegate.createRingBufferAdmin(contextName, getName());
131    }
132
133    /**
134     * Factory method to create a LoggerConfig.
135     *
136     * @param additivity True if additive, false otherwise.
137     * @param levelName The Level to be associated with the Logger.
138     * @param loggerName The name of the Logger.
139     * @param includeLocation "true" if location should be passed downstream
140     * @param refs An array of Appender names.
141     * @param properties Properties to pass to the Logger.
142     * @param config The Configuration.
143     * @param filter A Filter.
144     * @return A new LoggerConfig.
145     */
146    @PluginFactory
147    public static LoggerConfig createLogger(
148            @PluginAttribute("additivity") final String additivity,
149            @PluginAttribute("level") final String levelName,
150            @PluginAttribute("name") final String loggerName,
151            @PluginAttribute("includeLocation") final String includeLocation,
152            @PluginElement("AppenderRef") final AppenderRef[] refs,
153            @PluginElement("Properties") final Property[] properties,
154            @PluginConfiguration final Configuration config,
155            @PluginElement("Filter") final Filter filter) {
156        if (loggerName == null) {
157            LOGGER.error("Loggers cannot be configured without a name");
158            return null;
159        }
160
161        final List<AppenderRef> appenderRefs = Arrays.asList(refs);
162        Level level;
163        try {
164            level = Level.toLevel(levelName, Level.ERROR);
165        } catch (final Exception ex) {
166            LOGGER.error(
167                    "Invalid Log level specified: {}. Defaulting to Error",
168                    levelName);
169            level = Level.ERROR;
170        }
171        final String name = loggerName.equals(LoggerConfig.ROOT) ? Strings.EMPTY : loggerName;
172        final boolean additive = Booleans.parseBoolean(additivity, true);
173
174        return new AsyncLoggerConfig(name, appenderRefs, filter, level,
175                additive, properties, config, includeLocation(includeLocation));
176    }
177
178    // Note: for asynchronous loggers, includeLocation default is FALSE
179    protected static boolean includeLocation(final String includeLocationConfigValue) {
180        return Boolean.parseBoolean(includeLocationConfigValue);
181    }
182
183    /**
184     * An asynchronous root Logger.
185     */
186    @Plugin(name = "asyncRoot", category = "Core", printObject = true)
187    public static class RootLogger extends LoggerConfig {
188
189        private static final long serialVersionUID = 1L;
190
191        @PluginFactory
192        public static LoggerConfig createLogger(
193                @PluginAttribute("additivity") final String additivity,
194                @PluginAttribute("level") final String levelName,
195                @PluginAttribute("includeLocation") final String includeLocation,
196                @PluginElement("AppenderRef") final AppenderRef[] refs,
197                @PluginElement("Properties") final Property[] properties,
198                @PluginConfiguration final Configuration config,
199                @PluginElement("Filter") final Filter filter) {
200            final List<AppenderRef> appenderRefs = Arrays.asList(refs);
201            Level level;
202            try {
203                level = Level.toLevel(levelName, Level.ERROR);
204            } catch (final Exception ex) {
205                LOGGER.error(
206                        "Invalid Log level specified: {}. Defaulting to Error",
207                        levelName);
208                level = Level.ERROR;
209            }
210            final boolean additive = Booleans.parseBoolean(additivity, true);
211
212            return new AsyncLoggerConfig(LogManager.ROOT_LOGGER_NAME,
213                    appenderRefs, filter, level, additive, properties, config,
214                    AsyncLoggerConfig.includeLocation(includeLocation));
215        }
216    }
217}