> 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
