详解log4j2(下) - Async/MongoDB/Flume Appender 按日志级别区分文件输出

1. 按日志级别区分文件输出

有些人习惯按日志信息级别输出到不同名称的文件中，如info.log，error.log，warn.log等，在log4j2中可通过配置Filters来实现。

假定需求是把INFO及以下级别的信息输出到info.log，WARN和ERROR级别的信息输出到error.log，FATAL级别输出到fatal.log，配置文件如下：

<Configuration status="WARN" monitorInterval="300">
	<properties>
        <property name="LOG_HOME">D:/logs</property>
    </properties>
	<Appenders>
		<Console name="Console" target="SYSTEM_OUT">
			<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n" />
		</Console>

		<RollingRandomAccessFile name="InfoFile"
			fileName="${LOG_HOME}/info.log"
			filePattern="${LOG_HOME}/$${date:yyyy-MM}/info-%d{yyyy-MM-dd}-%i.log">
			<Filters>
				<ThresholdFilter level="warn" onMatch="DENY" onMismatch="NEUTRAL" />
				<ThresholdFilter level="trace" onMatch="ACCEPT" onMismatch="DENY" />
			</Filters>
			<PatternLayout pattern="%date{yyyy-MM-dd HH:mm:ss.SSS} %level [%thread][%file:%line] - %msg%n" />
			<Policies>
				<TimeBasedTriggeringPolicy />
				<SizeBasedTriggeringPolicy size="10 MB" />
			</Policies>
			<DefaultRolloverStrategy max="20" />
		</RollingRandomAccessFile>

		<RollingRandomAccessFile name="ErrorFile"
			fileName="${LOG_HOME}/error.log"
			filePattern="${LOG_HOME}/$${date:yyyy-MM}/error-%d{yyyy-MM-dd}-%i.log">
			<Filters>
				<ThresholdFilter level="fatal" onMatch="DENY" onMismatch="NEUTRAL" />
				<ThresholdFilter level="warn" onMatch="ACCEPT" onMismatch="DENY" />
			</Filters>
			<PatternLayout pattern="%date{yyyy-MM-dd HH:mm:ss.SSS} %level [%thread][%file:%line] - %msg%n" />
			<Policies>
				<TimeBasedTriggeringPolicy />
				<SizeBasedTriggeringPolicy size="10 MB" />
			</Policies>
			<DefaultRolloverStrategy max="20" />
		</RollingRandomAccessFile>

		<RollingRandomAccessFile name="FatalFile"
			fileName="${LOG_HOME}/fatal.log"
			filePattern="${LOG_HOME}/$${date:yyyy-MM}/fatal-%d{yyyy-MM-dd}-%i.log">
			<Filters>
				<ThresholdFilter level="fatal" onMatch="ACCEPT" onMismatch="DENY" />
			</Filters>
			<PatternLayout pattern="%date{yyyy-MM-dd HH:mm:ss.SSS} %level [%thread][%file:%line] - %msg%n" />
			<Policies>
				<TimeBasedTriggeringPolicy />
				<SizeBasedTriggeringPolicy size="10 MB" />
			</Policies>
			<DefaultRolloverStrategy max="20" />
		</RollingRandomAccessFile>
	</Appenders>

	<Loggers>
		<Root level="trace">
			<AppenderRef ref="Console" />
			<AppenderRef ref="InfoFile" />
			<AppenderRef ref="ErrorFile" />
			<AppenderRef ref="FatalFile" />
		</Root>
	</Loggers>
</Configuration>

测试代码：

	public static void main(String[] args) {
		Logger logger = LogManager.getLogger(Client.class);
		logger.trace("trace level");
		logger.debug("debug level");
		logger.info("info level");
		logger.warn("warn level");
		logger.error("error level");
		logger.fatal("fatal level");
	}

2 异步写日志

配置文件：

<Configuration status="WARN" monitorInterval="300">
	<properties>
		<property name="LOG_HOME">D:/logs</property>
		<property name="FILE_NAME">mylog</property>
	</properties>

	<Appenders>
		<Console name="Console" target="SYSTEM_OUT">
			<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n" />
		</Console>
		<RollingRandomAccessFile name="MyFile"
			fileName="${LOG_HOME}/${FILE_NAME}.log"
			filePattern="${LOG_HOME}/$${date:yyyy-MM}/${FILE_NAME}-%d{yyyy-MM-dd HH-mm}-%i.log">
			<PatternLayout
				pattern="%date{yyyy-MM-dd HH:mm:ss.SSS} %level [%thread][%file:%line] - %msg%n" />
			<Policies>
				<TimeBasedTriggeringPolicy interval="1" />
				<SizeBasedTriggeringPolicy size="10 MB" />
			</Policies>
			<DefaultRolloverStrategy max="20" />
		</RollingRandomAccessFile>
		<Async name="Async">
			<AppenderRef ref="MyFile" />
		</Async>
	</Appenders>

	<Loggers>
		<Logger name="asynclog" level="trace" additivity="false" >
			<AppenderRef ref="Async" />
		</Logger>
		<Root level="error">
			<AppenderRef ref="Console" />
		</Root>
	</Loggers>
</Configuration>

测试代码：

	public static void main(String[] args) {
		Logger logger = LogManager.getLogger("asynclog");
		logger.trace("trace level");
		logger.debug("debug level");
		logger.info("info level");
		logger.warn("warn level");
		logger.error("error level");
		logger.fatal("fatal level");
	}

3 输出到MongoDB

添加依赖：

		<dependency>
			<groupId>org.apache.logging.log4j</groupId>
			<artifactId>log4j-nosql</artifactId>
			<version>2.5</version>
		</dependency>
		<dependency>
			<groupId>org.mongodb</groupId>
			<artifactId>mongo-java-driver</artifactId>
			<version>3.2.2</version>
		</dependency>

配置文件：

<Configuration status="WARN" monitorInterval="300">
	<Appenders>
		<Console name="Console" target="SYSTEM_OUT">
			<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n" />
		</Console>

		<NoSql name="databaseAppender">
			<MongoDb databaseName="test" collectionName="errorlog"
				server="localhost" port="27017" />
		</NoSql>
	</Appenders>

	<Loggers>
		<Logger name="mongolog" level="trace" additivity="false">
			<AppenderRef ref="databaseAppender" />
		</Logger>
		<Root level="error">
			<AppenderRef ref="Console" />
		</Root>
	</Loggers>
</Configuration>

4 输出到Flume

Flume配置(flume-conf.properties)

agent1.sources=source1
agent1.sinks=sink1
agent1.channels=channel1 

agent1.sources.source1.type=avro
agent1.sources.source1.channels=channel1
agent1.sources.source1.bind=0.0.0.0
agent1.sources.source1.port=41414

agent1.sinks.sink1.type=file_roll
agent1.sinks.sink1.sink.directory=D:/log
agent1.sinks.sink1.channel=channel1
agent1.sinks.sink1.sink.rollInterval=86400
agent1.sinks.sink1.sink.batchSize=100
agent1.sinks.sink1.sink.serializer=text
agent1.sinks.sink1.sink.serializer.appendNewline = false

agent1.channels.channel1.type=file
agent1.channels.channel1.checkpointDir=D:/log/checkpoint
agent1.channels.channel1.dataDirs=D:/log/data

启动Flume（注：测试环境为windows）

flume-ng.cmd agent --conf ../conf/ --conf-file ../conf/flume-conf.properties -name agent1

添加依赖：

		<dependency>
			<groupId>org.apache.logging.log4j</groupId>
			<artifactId>log4j-flume-ng</artifactId>
			<version>2.5</version>
		</dependency>

配置文件：

<Configuration status="WARN" monitorInterval="300">
	<Appenders>
		<Flume name="eventLogger" compress="false">
			<Agent host="127.0.0.1" port="41414" />
			<RFC5424Layout enterpriseNumber="18060" includeMDC="true" appName="MyApp" />
		</Flume>
	</Appenders>
	<Loggers>
		<Root level="trace">
			<AppenderRef ref="eventLogger" />
		</Root>
	</Loggers>
</Configuration>