It will be good to understand a use case where an operator needs a
specific appender.
IMO, an operator designer defines *what* should be logged and dev-ops
team defines *where* to log.
Thank you,
Vlad
On 4/10/17 16:27, Munagala Ramanath wrote:
Yes, I understand, I was just wondering if individual operators could
define the appenders
they potentially need at compile time and then the operator callbacks could
simply
check the desired runtime condition and add the appropriate appender.
Or are we saying there are scenarios where we absolutely cannot create the
appender beforehand ?
So broadly speaking, my question is whether the combination of providing
predefined appenders
and the PropertyConfigurator capabilities meets the need.
Ram
On Mon, Apr 10, 2017 at 2:18 PM, Sergey Golovko <ser...@datatorrent.com>
wrote:
Ram,
Really the new appender class must extend the abstract class
AppenderSkeleton. And in order to add a new appender programmatically in
Java, some code in Apex should call the following log4j method:
org.apache.log4j.Logger.getRootLogger().addAppender(Appender newAppender)
The general idea of my proposal is "*based on some runtime parameter(s) to
provide ability to create an appender instance via reflection and add it to
the list of active log4j appenders*".
Thanks,
Sergey
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
