[logback-user] Configuring properties via XML

[Adam Gordon]

Gah!  Bitten by RTFM again...thanks for the assistance.

--adam

http://gordonizer.com



On Fri, Nov 9, 2012 at 12:02 AM, ceki <ceki at qos.ch> wrote:

> Regarding race conditions, note that the MDC manages contextual
> information on a per thread basis [1].
>
> [1] http://logback.qos.ch/manual/**mdc.html<http://logback.qos.ch/manual/mdc.html>
>
>
> On 09.11.2012 01:42, Adam Gordon wrote:
>
>> I was able to get this working using the SiftingAppender.  Thanks!  My
>> request filter pulls the child app name from the URI and sets the MDC
>> variable which yields the appropriate behavior of Spring logging to the
>> correct log files.
>>
>> One final question:  is this going to be subject to race conditions?  If
>> user A is using child app A at the same time as user B is using child
>> app B, they're going to go through the same request filter so it's
>> feasible that A's value gets set and that thread goes to do some
>> intensive business logic (which let's say has a bunch of logging), B's
>> thread comes in and changes the value, will A's thread suddenly switch
>> log files?
>>
>> I guess the real question is when does the SiftingAppender query MDC for
>> the value and when does it update it for the nested <appender>?
>>
>> --adam
>>
>> http://gordonizer.com
>>
>>
>>
>> On Thu, Nov 8, 2012 at 2:27 PM, ceki <ceki at qos.ch <mailto:ceki at qos.ch>>
>>
>> wrote:
>>
>>
>>     Have you looked at SiftingAppender [1]? If you can set an MDC
>>     variable at the beginning of a request served by each child app, the
>>     results should be rather close to what you are aiming. Give it a try.
>>
>>     [1] http://logback.qos.ch/manual/_**_appenders.html#**SiftingAppender<http://logback.qos.ch/manual/__appenders.html#SiftingAppender>
>>
>>     <http://logback.qos.ch/manual/**appenders.html#SiftingAppender<http://logback.qos.ch/manual/appenders.html#SiftingAppender>
>> **>
>>
>>
>>     On 08.11.2012 19:54, Adam Gordon wrote:
>>
>>         Ok, I really should have thought about what I really needed
>>         before posting.
>>
>>         We have a "parent" GWT web application and we have children
>>         applications
>>         that are plugged into it.  The children can run as standalone web
>>         applications but this is really only for development.  Since
>>         each child
>>         can run independently, each has its own logback.xml file.
>>
>>         Unfortunately, when the parent is built, the children are just
>>         JAR file
>>         dependencies and the parent also has it's own logback.xml file.
>>
>>         Using only the parent's logback.xml file, we can configure
>> different
>>         appenders (and thus different log files) for each of the
>>         children, but
>>         this only works because of the child namespacing (the Java package
>>         name).  The parent's logback.xml defines the root logger to use
>> the
>>         parent's appender.  What this means is that if the children are
>>         using a
>>         common framework, say Spring, all the Spring logging doesn't go
>>         into the
>>         correct child's logfile, but rather the parent's.
>>
>>         What we need is a way to either allow each child it's own,
>>         completely
>>         separate logging configuration or we need to "tag" the logging
>>         statement
>>         in the parent's log file with some name that indicates which
>>         child the
>>         message came from.
>>
>>         I was looking at the concept of a context selector, but it
>>         wasn't clear
>>         how I'd be able to configure this to return the correct
>>         LoggingContext
>>         depending on which child issued the logging statement.
>>
>>         Alternatively, I suppose I could add a filter which "sets" the
>>         current
>>         logging context based on the request URI - the children's
>>         request URIs
>>         are also namespaced so that each child's request URI always
>>         starts with
>>         /child_name/...
>>
>>         Was this clear?  Do anyone have any thoughts on how best to
>> approach
>>         this problem?
>>
>>         Thanks,
>>
>>         --adam
>>
>>         http://gordonizer.com
>>
>>
>>
>>         On Thu, Nov 8, 2012 at 11:01 AM, ceki <ceki at qos.ch
>>         <mailto:ceki at qos.ch> <mailto:ceki at qos.ch <mailto:ceki at qos.ch>>>
>>
>>
>>         wrote:
>>
>>
>>              Please see [1] in the docs. For your use case, you need to
>>         define
>>              the property in the context scope [2].
>>
>>              [1]
>>         http://logback.qos.ch/manual/_**___configuration.html#____**
>> variableSubstitution<http://logback.qos.ch/manual/____configuration.html#____variableSubstitution>
>>         <http://logback.qos.ch/manual/**__configuration.html#__**
>> variableSubstitution<http://logback.qos.ch/manual/__configuration.html#__variableSubstitution>
>> >
>>
>>
>>         <http://logback.qos.ch/manual/**__configuration.html#__**
>> variableSubstitution<http://logback.qos.ch/manual/__configuration.html#__variableSubstitution>
>>         <http://logback.qos.ch/manual/**configuration.html#**
>> variableSubstitution<http://logback.qos.ch/manual/configuration.html#variableSubstitution>
>> >>
>>              [2]
>>         http://logback.qos.ch/manual/_**___configuration.html#scopes<http://logback.qos.ch/manual/____configuration.html#scopes>
>>         <http://logback.qos.ch/manual/**__configuration.html#scopes<http://logback.qos.ch/manual/__configuration.html#scopes>
>> >
>>
>>
>>              <http://logback.qos.ch/manual/**__configuration.html#scopes<http://logback.qos.ch/manual/__configuration.html#scopes>
>>         <http://logback.qos.ch/manual/**configuration.html#scopes<http://logback.qos.ch/manual/configuration.html#scopes>
>> >>
>>
>>
>>              On 08.11.2012 18:54, Adam Gordon wrote:
>>
>>                  The Layout chapter indicates it supports property value
>>                  retrieval via
>>                  %property{key} and states that the logging context is
>>         where one
>>                  might
>>                  put a property (along w/ System properties).  I believe
>>         log4j
>>                  did this
>>                  w/ the <param name="key_name" value="some_value">
>>         element in the
>>                  <appender> and referenced it via %properties{key_name}.
>>
>>                  I'm not seeing how to do this in Logback in XML. Would
>>         it go in the
>>                  <logger> element?  What's the syntax?  Could someone
>> please
>>                  point me to
>>                  the relevant section in the appropriate chapter of the
>>         manual?
>>
>>                  Thanks,
>>
>>                  --adam
>>
>>
>>
>>     --
>>     Ceki
>>     65% of statistics are made up on the spot
>>
>
>
>
> --
> Ceki
> 65% of statistics are made up on the spot
> ______________________________**_________________
> Logback-user mailing list
> Logback-user at qos.ch
> http://mailman.qos.ch/mailman/**listinfo/logback-user<http://mailman.qos.ch/mailman/listinfo/logback-user>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qos.ch/pipermail/logback-user/attachments/20121109/7c0999ef/attachment.html>