Replace Log4j by SLF4J

[lpellegr]

SLF4J is an abstraction that allows to plug the desired logging framework at deployment time.

I suggest to replace Log4j by SLF4J so that the desired backend implementation can easily be changed. Especially, it would be interesting to use Logback as the logging framework. The reasons to choose Logback over Log4j are explained in the link provided below:

http://logback.qos.ch/reasonsToSwitch.html

[lpellegr]

Logback has built-in support for log rotation with compression:

http://logback.qos.ch/manual/appenders.html#TimeBasedRollingPolicy

[fviale]

:+1:

Log4j seems to be frozen and not evolving any more.

But won't this change be a bit painful ?

[lpellegr]

I haven't checked yet the work that is required for this task but if it is done for scheduling only I think it should not be too complex. If I remember, only ProActive Programming is using custom appender implementations for collecting distributed logs.