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From Dominik Psenner <dpsen...@gmail.com>
Subject Re: Injecting properties into LoggingEvent
Date Sun, 23 Oct 2016 19:13:43 GMT
Responding inline..

On 23 Oct 2016 4:04 p.m., "Nicholas Duane" <nickdu@msn.com> wrote:
>
> Is there a way for me to add properties to a LoggingEvent without the
user doing anything out of the ordinary.  Maybe it's even best to assume an
existing application which is using log4net. I would like to take this
existing log4net application and without them changing any code,
configuration changes are ok, I would like to add properties to each
LoggingEvent which is created from their log statements like:
>
>
> logger.Error();
>
> logger.Info();
>
> logger.Debug();
>
> etc.
>
>

That requirement sounds like you would like to:

// thread properties...
log4net.LogicalThreadContext.Properties["CustomColumn"] = "Custom value";
log.Info("Message");

// ...or global properties log4net.GlobalContext.Properties["CustomColumn"]
= "Custom value";

These automatically set these properties on the logging events and you can
then filter those with a propertyfilter as you write here:

> such that I could use the PropertyFilter filter to filter out events?  I
want to set a property based on the level of the event.  I could of course
use the LevelRangeFilter but in other cases I'm using the PropertyFilter
and was figuring it might be nice to do it the same for all events.
>
>
> This other case where I'm using the PropertyFilter is for new events
we've introduced.  These are what we call "compliance" and "business"
events.  We originally introduced a "compliance" event and at that time I
introduced a custom level for that.  However, I'm trying to move away from
defining custom levels and instead use a property on the event to
distinguish its "category".  For these new events which don't fit nicely
into the level gradient I've introduced a method for developers to use to
log them called LogEvent().  They will pass in their logger, the category
of the event, and the event.  In this scenario it's easy for me to set
properties on the LoggingEvent.

To me this sounds like you are trying to force the logging framework to do
something different than the rest of the application logs do. If thats the
case, then let me warn you that it might not be a good idea. Logs could be
only a byproduct of the feature you would like to implement. If you are
implementing application features through the logging framework, logging is
too smart and does too much. Try to design your applocation so that it
could do its job even if logging was not there.

However it sounds like this works for you, therefore I do not try to work
out anything.

>  However, for what we call the diagnostic events, those that are logged
using the methods exposed by log4net, we don't want them to have to do
anything different than they were doing.  If they want to log an error they
would still use:
>
>
> logger.Error("this is my error");
>
>
> or a warning:
>
>
> logger.Warn("this is my warning");
>
>
> etc.
>
>
> Ideally I would like to set the "category" on those events also so that
by the time they make it to the appender it has this "category" property.
Is there a way to do that?

This sounds like this:

http://stackoverflow.com/questions/9015432/how-can-i-inject-a-property-for-only-one-call-in-log4net

Best regards,
Dominik

>
>
> Thanks,
>
> Nick
>
>
> ________________________________
> From: Dominik Psenner <dpsenner@gmail.com>
> Sent: Sunday, October 23, 2016 9:18 AM
>
> To: Log4NET User
> Subject: Re: Injecting properties into LoggingEvent
>
>
> Sorry, I cannot grasp your requirements. Please try to explain your
usecase better in a way that gives the document some kind of structure.
>
>
> On 23 Oct 2016 12:02 a.m., "Nicholas Duane" <nickdu@msn.com> wrote:
>>
>> Thank you for the suggestions.
>>
>>
>> We are already logging complex objects in many cases.  We have the
notion of a compliance event.  That's basically a map (IDictionary<string,
object>).  We're now adding business events.  However, even with these
"complex" events I don't want the map to contain the category, at least not
at event creation time.  I see an event as just a collection of
properties.  The act of logging it at a certain level or category is what
assigns the severity or category.  For example:
>>
>>
>> logger.Warn("this is my warning message");
>>
>>
>> logger.Error("this is my error message");
>>
>>
>> logger.Info("this is my info message");
>>
>>
>> In each of those cases if we assume the event is the message itself,
there is no criticality associated with that event.  It's the act of
logging that defines the event's criticality.  I want the same to be true
for the category.  I believe I have this working fine for our "complex"
events which don't fit into the Level gradient.  I expose a LogEvent()
method which logs at the Emergency level as I showed in the code I included
in the previous thread.  However, we also need to capture diagnostic
events, ones that are logged via the logging framework's methods:
>>
>>
>> logger.Error(...);
>>
>> logger.Warn(...);
>>
>>
>> What I am hoping to do is hook in some of my code and generate one of
our complex events each time the logging framework logs an event and will
map the level to one of our categories.  I can imagine that this might be
possible if I somehow wrap a logger, but as I mentioned I don't want the
user to have to call anything special at startup to hook up that wrapping.
I was hoping there would be a way for me to hook myself in via
configuration.  I'm ok with giving them a configuration file they need to
use but I don't want them to have to change any existing code them may have.
>>
>>
>> By the way, we did generate a custom log level for our compliance
event.  However I'm trying to move away from that as it was point out that
our events don't fit well within the level gradient.  So the new code for
logging a compliance event does not use that level.  Both the compliance
and business event would be logged at the Emergency level.  I would use the
category property to differentiate them.  Similar, I guess, to log4j2's
Markers.
>>
>>
>> Thanks,
>>
>> Nick
>>
>>
>> ________________________________
>> From: Dominik Psenner <dpsenner@gmail.com>
>> Sent: Saturday, October 22, 2016 1:29 PM
>> To: Log4NET User
>> Subject: Re: Injecting properties into LoggingEvent
>>
>>
>> What I am proposing here are a mere ideas that will need further
investigation. I have not tried any of these ideas. You will have to
prioritize these ideas based on your requirements.
>>
>> A. Implement an extension class for the ILog interface
>> B. Implement a custom ILog interface implementation and a LoggerFactory.
>> C. Define custom loglevels
>> D. Use thread context properties altogether with custom format layouts
>> E. Log "complex" classes that hold your category information and find a
way to format them
>>
>> There might be more things that you could do..
>>
>>
>> On 22 Oct 2016 5:31 p.m., "Nicholas Duane" <nickdu@msn.com> wrote:
>>>
>>> Is there a way for me to inject properties into a LoggingEvent?  I'm
trying to accomplish this without the user (of log4net) doing anything
special.  The only thing I could think of was wrapping loggers, and while
I'm not against doing that it would have to be done via configuration as I
don't want the user to have to do it programmatically.  Is there any way
for me to inject a logger wrapper via configuration?
>>>
>>>
>>> The reason I'm looking to do this is that I would like to set a
property on the LoggingEvent to use for filtering.  This property would be
determined based on the level property.  I could simply use the level
property for filtering, but I have other events which I generate which are
all logged at the Emergency level but have a different value for this
property so for them I'm using this property for filtering.  I don't have
the same issue with these other events because they are logged via an
extension method I provided on the ILog interface:
>>>
>>>
>>> public static class Logging
>>>
>>> {
>>>
>>>     public static void LogEvent(this ILog logger, Category category,
IEvent evnt)
>>>
>>>     {
>>>
>>>         if ((category != null) && (evnt != null))
>>>
>>>             {
>>>
>>>             evnt.SetCategory(category.Name);
>>>
>>>             LoggingEvent le = new LoggingEvent(null,
logger.Logger.Respository,
>>>
>>>                     logger.Logger.Name, Level.Emergency, evnt, null);
>>>
>>>             le.Properties["category"] = category.Name;
>>>
>>>             logger.Logger.Log(le);
>>>
>>>             }
>>>
>>>     }
>>>
>>> }
>>>
>>>
>>> So for instance when a user does the following:
>>>
>>>
>>> logger.Error("this is my error message");
>>>
>>> or
>>>
>>> logger.Warn("this is my warning message");
>>>
>>> or
>>>
>>> logger.Info("this is my info message");
>>>
>>>
>>> I would like to set the property "category" on the LoggingEvent to
"criticalDiagnostic".  When they do:
>>>
>>>
>>> logger.Debug("this is my debug message");
>>>
>>> or
>>>
>>> logger.Trace("this is my trace message");
>>>
>>>
>>> I would like to set the property "category" on the LoggingEvent to
"noncriticalDiagnostic".  Any way for me to do that automagically?
>>>
>>>
>>> I also posted this at:
>>>
>>>
>>>
http://stackoverflow.com/questions/40187597/injecting-properties-into-log4nets-loggingevent
>>>
>>>
>>> Thanks,
>>>
>>> Nick

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