asked on

Log4j - Implementation/Customization

I'm trying to implement Asynchronous logging in my app. My requirement is as mentioned below.

For Thread 1, Request Flow starts on Class A ---> Class B --> Class C ---> Class D ---> Classs E ........ -> Class M --> Flow ends

For Thread 2, Request Flow starts on Class A ---> Class B --> Class C ---> Class D ---> Classs E ........ -> Class M --> Flow ends

For Thread n, Request Flow starts on Class A ---> Class B --> Class C ---> Class D ---> Classs E ........ -> Class M --> Flow ends

This is my requirement: The log message needs to be persisted into DB as well as flat file through Asynchronous processing. I do not want to append the log message into my destination (destination would be JMSAppender ->DB) as soon as I invoke Logger methods (info, debug, warn..). I want to keep a separate buffer for each request thread and flush it into appender/destination at each mile stone (let's say for example, I would like to flush out the buffer in Class C and Class F, Class Class I ..)

I would like to know, what changes/design do we need to make in log4j to fit into my requirement Or Can I go without log4j?. Any suggestion please?

We want to make sure, this logging implementation should not lead to performance hit

ASKER CERTIFIED SOLUTION

Mick Barry

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MatrixStar

ASKER

Though, I use AsyncAppender, I may not able to keep a separate buffer for my each request (thread)..right?

Mick Barry

thats right, though the point of async appenders is that the logs are written from a seperate thread to the calling thread

Mick Barry

you can include the thread name in the log message format if you need to track which thread logged what

MatrixStar

ASKER

you are right, that's one way of doing that. I'm trying to find out a way collectively store message of one thread in a buffer and flush it out.

Anyway, Thanks

MatrixStar

ASKER

Though, I use AsyncAppender and buffer size 500, I see, the message is sent to target appender as soon as message is sent to AysyncAppender. any idea why is that?

Please look at my log4j configuration below:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd" >

<log4j:configuration threshold="all" debug="true" xmlns:log4j="http://jakarta.apache.org/log4j/">

<appender name="jmsQueueAppender" class="com.log.JMSQueueAppender">
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%-5p %t [%-40.40c] %x - %m%n"/>
</layout>
</appender>

<appender name="asyncAppender" class="org.apache.log4j.AsyncAppender">
<param name="BufferSize" value="500"/>
<appender-ref ref="jmsQueueAppender"/>
</appender>


<logger name="async" additivity="false">
<level value="DEBUG"/>
<appender-ref ref="asyncAppender"/>

</log4j:configuration>

JMSQueueAppender

package com.log;

import org.apache.log4j.AppenderSkeleton;
import org.apache.log4j.spi.LoggingEvent;

public class JMSQueueAppender extends AppenderSkeleton {

public JMSQueueAppender() {

System.out.println("JMSQueueAppender is instantiated...");
}

@Override
protected void append(LoggingEvent event) {
System.out.println("JMSQueueAppender Thread: " + Thread.currentThread().getName());
System.out.println("JMSQueueAppender Appender test:" + event.getMessage());

}

@Override
public void close() {
// TODO Auto-generated method stub

}

@Override
public boolean requiresLayout() {
// TODO Auto-generated method stub
return false;
}

}


Servlet

      public class SampleServlet extends HttpServlet {

private static final Logger async = Logger.getLogger("async."+CommandServlet.class);

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

//console.info("console:Console log test.");

System.out.println("CommandServlet Thread: " + Thread.currentThread().getName());
async.info("Async:ASYNC log test.");
}

}

MatrixStar

ASKER

Sorry for my earlier message got messed up. I couldn't re-edit it to corrrect,

My Question is, Doesn't Dispatcher thread wait until the buffer is getting filled up before send the message to destination?

Mick Barry

no it doesn't wait

MatrixStar

ASKER

I'm going with AsyncAppender as of now, will keep post if I find any other best solution. Thanks

mrcoffee365

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