Comments on: Asynchronous logging with log4j

By: Nickle

Nickle — Wed, 08 Feb 2012 15:58:05 +0000

It’s really cool article. I learned a lot from this. thank you very much.

By: ricardoz

ricardoz — Fri, 25 Nov 2011 17:42:21 +0000

@Praveen

The info logged and the format of the log file itself are part of the log4j configuration. You can read about it on log4j official website (http://logging.apache.org/log4j/1.2/).

Additionally you might want to check that your code is being compiled with the debbuging flag on, otherwise line numbers won’t be printed on stack traces.

By: Praveen

Praveen — Mon, 14 Nov 2011 20:48:43 +0000

Thanks for this simple explanation. I implemented this and worked fine, except that the filename/line number in the invoking method is not being displayed. Is there any other configuration involved?

By: Vishak

Vishak — Tue, 01 Feb 2011 11:06:47 +0000

AsyncAppender uses FIFO (First in First Out) logic. It uses BoundedFIFO utility for this. Pls refer this documentation for more http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/helpers/BoundedFIFO.html

So the sequence inwhich logging happens will be correct

By: ricardoz

ricardoz — Tue, 12 Oct 2010 11:53:50 +0000

Ramesh, hi.

1. It should be maintained, at least within the same thread in your application. Are you logging from a single thread environment?

2. No, that’s exactly the purpose of the buffer, if it fills up it will cause en IO wait on your application until the logger can catch up. If you find this happening a lot, you should increase the buffer.

By: Ramesh

Ramesh — Mon, 11 Oct 2010 08:48:38 +0000

Thanks for sharing the great article, can you clarify my questions

1) when we use this async mode, whether the sequence of the log messages maintained? for me it is not. If the sequence is not maintained it does not make any sense rite?

2) When the buffer fills us it will use sync mode, but is this part of user thread or separate thread by log4j? because the main point here is not to slowdown the user’s thread.

By: ricardoz

ricardoz — Tue, 14 Sep 2010 04:23:37 +0000

No, it will try to flush it as soon as possible. The buffer is used in case the number of incoming events overcome the IO capability of the output file.

By: Matrixstar

Matrixstar — Tue, 14 Sep 2010 03:46:20 +0000

Thank you for your nice article.

Got a question about the below statement.

“The BufferSize parameter of the AsyncAppender defines the number of entries that will be stored in memory to let the actual appender catch up flushing them to their final destination.”

I tried AsyncAppender, but what I noticed is, the log message is sent to the destination appender (for example FileAppender) from AsyncAppender as soon the message is sent to AsyncAppender. Doesn’t AsyncAppender dispatcher thread wait until the buffer fills up? Your advise will be much appreciated.

By: Neeraj Jaiswal

Neeraj Jaiswal — Tue, 07 Sep 2010 14:04:30 +0000

Hey,

I really like your article. Infact I was also working on improving the use of log4j.

Check out this article of mine on version based login. Its just a basic code.

http://www.technimi.com/index.php?do=/blog/version-based-logging-using-log4j/