All sounds reasonable to me. I'm not sure any of the statements you made go
against anything I have stated. Please let me know if you think otherwise.
In your authentication module, you log all levels through its logger, right?
You don't use separate loggers to log different levels do you?
Thanks,
Nick
> Date: Mon, 31 Aug 2015 15:02:09 -0700
> Subject: Re: approach for defining loggers
> From: garydgreg...@gmail.com
> To: log4j-user@logging.apache.org
>
> I think of levels as "how important is this" and "who needs to know this".
> Some of the art of logging is deciding who you audience is. To help your
> development team chase down a bug, you want to make sure that the app logs
> interesting events at the DEBUG and TRACE level. This is different that
> "what it is I am telling this audience", which is where I use loggers. To
> tell who comes in and out of the system, I have logging in the
> authentication module. To tell what kind of SQL goes to the database, I
> have DEBUG logging in my DB interface code.
>
> I think that once you start chasing down issues and bugs, and writing code
> to help you do that, then it might become more obvious, as to what to do.
>
> Gary
>
> On Mon, Aug 31, 2015 at 2:51 PM, Nicholas Duane <nic...@msn.com> wrote:
>
> > I did look through a bit of documentation on markers:
> >
> > https://logging.apache.org/log4j/2.0/manual/markers.html
> >
> > http://stackoverflow.com/questions/16813032/what-is-markers-in-java-logging-frameworks-and-that-is-a-reason-to-use-them
> >
> > My initial impression is that I don't want to use markers. What I'd like
> > to be able to say is:
> >
> > "log the way you have been logging in the past. You don't need to know
> > about any special loggers. Use your own. Here is a new level for our new
> > type of "event". Use that to log this new event."
> >
> > I guess I'm not understanding your vernacular in terms of levels. In my
> > mind the different levels also define different "types" of events. For
> > instance, DEBUG and less specific I would see as tracing type events which
> > are non-functional in nature. They are purely for understanding the call
> > flow, or for performance gathering, or detailed diagnosis. Those could be
> > turned off totally without having much impact on system management. The
> > same can't be said for FATAL to INFO. These levels should always be on so
> > that you can properly manage the system.
> >
> > Thanks,
> > Nick
> >
> > > Date: Mon, 31 Aug 2015 08:37:25 -0700
> > > Subject: Re: approach for defining loggers
> > > From: garydgreg...@gmail.com
> > > To: log4j-user@logging.apache.org
> > >
> > > Hi Nick,
> > >
> > > Creating a single new level is seldom the right solution IMO. It's not
> > like
> > > you are missing a level of granularity (we have custom level examples
> > that
> > > demonstrate that, like a VERBOSE level that sits between INFO and DEBUG).
> > > It sounds like you need to use _hierarchical_ loggers and/or markers.
> > >
> > > The fact that the level is called BUSINESS is also a hint that a level is
> > > not quite right because it does not fit in the Level vernacular (INFO,
> > > WARN, and so on).
> > >
> > > If you needed a different set of levels, that would be another story
> > (like
> > > the DEFCON levels example).
> > >
> > > Gary
> > >
> > > On Mon, Aug 31, 2015 at 8:10 AM, Nicholas Duane <nic...@msn.com> wrote:
> > >
> > > > 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
> > > > >
> > > > > ---------------------------------------------------------------------
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> > > > >
> > > >
> > > >
> > >
> > >
> > >
> > > --
> > > E-Mail: garydgreg...@gmail.com | ggreg...@apache.org
> > > Java Persistence with Hibernate, Second Edition
> > > <http://www.manning.com/bauer3/>
> > > JUnit in Action, Second Edition <http://www.manning.com/tahchiev/>
> > > Spring Batch in Action <http://www.manning.com/templier/>
> > > Blog: http://garygregory.wordpress.com
> > > Home: http://garygregory.com/
> > > Tweet! http://twitter.com/GaryGregory
> >
> >
>
>
>
> --
> E-Mail: garydgreg...@gmail.com | ggreg...@apache.org
> Java Persistence with Hibernate, Second Edition
> <http://www.manning.com/bauer3/>
> JUnit in Action, Second Edition <http://www.manning.com/tahchiev/>
> Spring Batch in Action <http://www.manning.com/templier/>
> Blog: http://garygregory.wordpress.com
> Home: http://garygregory.com/
> Tweet! http://twitter.com/GaryGregory
