Thanks for the feedback. I will look into Markers and MDC.
With respect to using a separate logger, it would seem I would lose the
information about what application code, eg. the class logger, is sourcing the
event. We would like to have this information. On top of that, it seems odd,
maybe to me only, that for this new level we have our own logger. It seemed
reasonable to me that this new event we want to capture is just a new level.
Just like a DEBUG event is different from an INFO event. If I define a
BUSINESS level why would that not follow the same design as the current levels?
You wouldn't suggest having different loggers for TRACE DEBUG INFO WARN ERROR
FATAL, would you? I think one of the reasons someone on our side is suggesting
I have separate loggers is that they think the overhead of filtering at the
appender is going to have a noticeable impact. Our plan, at least the one I
have now in my head, is that we'll have some number of appenders in the root.
We'll then filter x < INFO events to a tracing appender, INFO <= x <= FATAL to
a logging appender, and our custom level will go to another appender. Thoughts?
Thanks,
Nick
> Subject: Re: approach for defining loggers
> From: ralph.go...@dslextreme.com
> Date: Sat, 29 Aug 2015 20:59:36 -0700
> To: log4j-user@logging.apache.org
>
>
> > On Aug 29, 2015, at 7:44 PM, Nicholas Duane <nic...@msn.com> wrote:
> >
> > I'm curious if there is a prescribed approach to defining loggers. Let me
> > state what my assumption is. I assume that normally if some piece of code
> > wants to log events/messages that it should create a logger for itself. I
> > guess a reasonable name to use is the class name itself. In terms of
> > logger configuration I would expect that no loggers are specified in the
> > log4j configuration UNLESS is needs settings other than the default. The
> > root logger would specify the default settings, eg. level and appenders.
> > If some piece of code tied to a logger needs to enable tracing in order to
> > debug an issue then you would add that logger to the configuration and set
> > the level less specific for that logger. Is this a typical and reasonable
> > approach?
>
> What you describe here is the common convention. It is a reasonable approach.
>
> >
> > I asked because we have the need for a new type of event. To have this
> > event flow to where we want it to flow the plan is to have a custom level
> > and have all events at that level captured by a specific appender. My
> > assumption was that for existing applications we'd just need to add our
> > appender to the root and add our custom level. The app would need to be
> > modified to log our new event at the custom level. However, someone
> > suggested that we could also create a separate logger for this event. My
> > thinking is that while we don't ever want to turn off logging of this
> > event, loggers represent "event sources", e.g the code raising the events
> > and thus having multiple different pieces of code use the same logger
> > wouldn't allow you to turn on/off logging from those different sections of
> > code independently. I think the current configuration includes all the
> > loggers. Normally I would expect there to be many, on the order of 10's or
> > 100's, loggers within an application. However, in the case I was given
> > there were only a handful because I think this handful is shared. So as I
> > mentioned, this doesn't sound like an ideal design as you have less
> > granularity on what you can turn on/off.
>
> You have a few options. Using a CustomLevel would not be the option I would
> choose. Creating a custom Logger will certainly work and makes routing the
> message to the appropriate appender rather easy. Another approach is to use
> Markers. Markers are somewhat hierarchical so you can use them for a variety
> of purposes. If you look at how Log4j handles event logging it actually does
> both - it specifies EventLogger as the name of the logger to use and it uses
> Markers to identify the kind of event.
>
> A third option is to use the MDC or Logger properties. If you do that then
> you can have information included in the actual logging event that can affect
> how it is routed. I also built a system that uses the RFC5424 format so that
> the event could have lots of key/value pairs to identify the events.
>
> Unfortunately, without knowing more details I don’t know that I can give you
> a better idea on how I would implement it.
>
> Ralph
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: log4j-user-unsubscr...@logging.apache.org
> For additional commands, e-mail: log4j-user-h...@logging.apache.org
>
