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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements. See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache license, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License. You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the license for the specific language governing permissions and
15   * limitations under the license.
16   */
17  package org.apache.logging.log4j.core.async;
18  
19  import java.util.Arrays;
20  import java.util.List;
21  
22  import org.apache.logging.log4j.Level;
23  import org.apache.logging.log4j.LogManager;
24  import org.apache.logging.log4j.core.Filter;
25  import org.apache.logging.log4j.core.LogEvent;
26  import org.apache.logging.log4j.core.config.AppenderRef;
27  import org.apache.logging.log4j.core.config.Configuration;
28  import org.apache.logging.log4j.core.config.LoggerConfig;
29  import org.apache.logging.log4j.core.config.Node;
30  import org.apache.logging.log4j.core.config.Property;
31  import org.apache.logging.log4j.core.config.plugins.Plugin;
32  import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
33  import org.apache.logging.log4j.core.config.plugins.PluginConfiguration;
34  import org.apache.logging.log4j.core.config.plugins.PluginElement;
35  import org.apache.logging.log4j.core.config.plugins.PluginFactory;
36  import org.apache.logging.log4j.core.jmx.RingBufferAdmin;
37  import org.apache.logging.log4j.core.util.Booleans;
38  import org.apache.logging.log4j.util.Strings;
39  
40  /**
41   * Asynchronous Logger object that is created via configuration and can be
42   * combined with synchronous loggers.
43   * <p>
44   * AsyncLoggerConfig is a logger designed for high throughput and low latency
45   * logging. It does not perform any I/O in the calling (application) thread, but
46   * instead hands off the work to another thread as soon as possible. The actual
47   * logging is performed in the background thread. It uses the LMAX Disruptor
48   * library for inter-thread communication. (<a
49   * href="http://lmax-exchange.github.com/disruptor/"
50   * >http://lmax-exchange.github.com/disruptor/</a>)
51   * <p>
52   * To use AsyncLoggerConfig, specify {@code <asyncLogger>} or
53   * {@code <asyncRoot>} in configuration.
54   * <p>
55   * Note that for performance reasons, this logger does not include source
56   * location by default. You need to specify {@code includeLocation="true"} in
57   * the configuration or any %class, %location or %line conversion patterns in
58   * your log4j.xml configuration will produce either a "?" character or no output
59   * at all.
60   * <p>
61   * For best performance, use AsyncLoggerConfig with the RandomAccessFileAppender or
62   * RollingRandomAccessFileAppender, with immediateFlush=false. These appenders have
63   * built-in support for the batching mechanism used by the Disruptor library,
64   * and they will flush to disk at the end of each batch. This means that even
65   * with immediateFlush=false, there will never be any items left in the buffer;
66   * all log events will all be written to disk in a very efficient manner.
67   */
68  @Plugin(name = "asyncLogger", category = Node.CATEGORY, printObject = true)
69  public class AsyncLoggerConfig extends LoggerConfig {
70  
71      private final AsyncLoggerConfigDelegate delegate;
72  
73      protected AsyncLoggerConfig(final String name,
74              final List<AppenderRef> appenders, final Filter filter,
75              final Level level, final boolean additive,
76              final Property[] properties, final Configuration config,
77              final boolean includeLocation) {
78          super(name, appenders, filter, level, additive, properties, config,
79                  includeLocation);
80          delegate = config.getAsyncLoggerConfigDelegate();
81          delegate.setLogEventFactory(getLogEventFactory());
82      }
83  
84      /**
85       * Passes on the event to a separate thread that will call
86       * {@link #asyncCallAppenders(LogEvent)}.
87       */
88      @Override
89      protected void callAppenders(final LogEvent event) {
90          populateLazilyInitializedFields(event);
91  
92          if (!delegate.tryEnqueue(event, this)) {
93              final EventRoute eventRoute = delegate.getEventRoute(event.getLevel());
94              eventRoute.logMessage(this, event);
95          }
96      }
97  
98      private void populateLazilyInitializedFields(final LogEvent event) {
99          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 }