http://logging.apache.org/log4j/1.2/faq.html#3.6
Log4j has the ability to dynamically reload changes to the properties file via the *configureAndWatch()* method of *PropertyConfigurator*. If this is already baked in, could devops simply change the properties file if we provide an enhanced set of appenders for the desired use cases ? Ram On Mon, Apr 10, 2017 at 2:04 PM, Vlad Rozov <v.ro...@datatorrent.com> wrote: > It will require application recompilation and repackaging. The proposed > functionality is for dev-ops to be able to route application logging to a > preferred destination without recompiling applications. It is run-time > configuration vs compile time hardcoded appender. > > Thank you, > > Vlad > On 4/10/17 11:23, Munagala Ramanath wrote: > >> You can do it in a trivial derived class without changing the base class. >> >> Ram >> >> On Mon, Apr 10, 2017 at 11:19 AM, Vlad Rozov <v.ro...@datatorrent.com> >> wrote: >> >> Does not the proposal to use Logger.addAppender() requires modifications >>> to used operators code? >>> >>> Thank you, >>> >>> Vlad >>> >>> On 4/10/17 10:58, Munagala Ramanath wrote: >>> >>> People can currently do this by simply implementing the Appender >>>> interface >>>> and adding it >>>> with Logger.addAppender() in the setup method. Why do we need something >>>> more elaborate ? >>>> >>>> Ram >>>> >>>> On Mon, Apr 10, 2017 at 10:30 AM, Sergey Golovko < >>>> ser...@datatorrent.com> >>>> wrote: >>>> >>>> The configuration of a log4j appender via log4j configuration file is a >>>> >>>>> static configuration that cannot be disabled/enabled and managed >>>>> dynamically by an application designer. The programmatic approach will >>>>> allow an application designer to specify which of the available log4j >>>>> appenders should be used for the specific application. >>>>> >>>>> It is not necessary Apex should use the predefined log4j appenders >>>>> only. >>>>> The log4j events contain useful but the very limited number of >>>>> properties >>>>> which values can be printed into output log4j sources. But based on the >>>>> knowledge of the software product workflow, the custom defined log4j >>>>> appender can extend a list of predefined output log events properties >>>>> and, >>>>> for instance for Apex, return: node, user name, application name, >>>>> application id, container id, operator name, etc. >>>>> >>>>> Also the output log events that are generated by a custom defined log4j >>>>> appender can be stored and indexed by any type of a full text search >>>>> database. It will allow the customers and developers to simplify >>>>> collection >>>>> of log events statistics and searching/filtering of specific events for >>>>> debugging and investigation. >>>>> >>>>> Thanks, >>>>> Sergey >>>>> >>>>> >>>>> On Mon, Apr 10, 2017 at 6:34 AM, Vlad Rozov <v.ro...@datatorrent.com> >>>>> wrote: >>>>> >>>>> +1 Apex engine does not own log4j config file - it is provided either >>>>> by >>>>> >>>>>> Hadoop or an application. Hadoop log4j config does not necessarily >>>>>> meet >>>>>> application logging requirements, but if log4j is provided by an >>>>>> application designer, who can only specify what to log, it may not >>>>>> meet >>>>>> operations requirements. Dev-ops should have an ability to specify >>>>>> where >>>>>> >>>>>> to >>>>> >>>>> log depending on the available infrastructure at run-time. >>>>>> >>>>>> It will be good to have an ability not only specify extra log4j >>>>>> appenders >>>>>> at lunch time, but also at run-time, the same way how log4j logger >>>>>> levels >>>>>> may be changed. >>>>>> >>>>>> Thank you, >>>>>> >>>>>> Vlad >>>>>> >>>>>> On 4/9/17 23:14, Priyanka Gugale wrote: >>>>>> >>>>>> We can always write a custom appender and add it by changing root >>>>>> appender >>>>>> in log4j config file. Can you explain how adding appender >>>>>> grammatically >>>>>> >>>>>>> would help? >>>>>>> >>>>>>> -Priyanka >>>>>>> >>>>>>> On Sun, Apr 9, 2017 at 11:50 AM, Sanjay Pujare < >>>>>>> san...@datatorrent.com >>>>>>> wrote: >>>>>>> >>>>>>> Please give some examples and/or use cases of this programmatic log4j >>>>>>> >>>>>>> appender. >>>>>>>> >>>>>>>> On Fri, Apr 7, 2017 at 8:40 PM, Sergey Golovko < >>>>>>>> ser...@datatorrent.com >>>>>>>> wrote: >>>>>>>> >>>>>>>> Hi All, >>>>>>>> >>>>>>>> I'd like to add supporting of a custom defined log4j appender that >>>>>>>>> can >>>>>>>>> be >>>>>>>>> added to Apex Application Master and Containers and be configurable >>>>>>>>> programmatically. >>>>>>>>> >>>>>>>>> Sometimes it is not trivial to control log4j configuration via >>>>>>>>> log4j >>>>>>>>> properties. And I think the having of the approach to add a log4j >>>>>>>>> >>>>>>>>> appender >>>>>>>>> >>>>>>>> programmatically will allow the customers and developers to plugin >>>>>>>> their >>>>>>>> >>>>>>> own custom defined log4j appenders and be much flexible for streaming >>>>>> >>>>>>> and >>>>>>>>> collection of Apex log events. >>>>>>>>> >>>>>>>>> I assume to provide generic approach for definition of the >>>>>>>>> >>>>>>>>> programmatic >>>>>>>> >>>>>>> log4j appender and to pass all configuration parameters including a >>>>>> >>>>>>> name >>>>>>>> >>>>>>> of >>>>>> >>>>>>> the Java class with implementation of the log4j appender via system >>>>>>>> >>>>>>>>> and/or >>>>>>>>> >>>>>>>> command line properties. >>>>>>>> >>>>>>>>> Thanks, >>>>>>>>> Sergey >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>> >> > -- _______________________________________________________ Munagala V. Ramanath Software Engineer E: r...@datatorrent.com | M: (408) 331-5034 | Twitter: @UnknownRam www.datatorrent.com | apex.apache.org
