Thanks Ralph. I'll start with
LOG4J2-1577 Add a Builder to the RoutingAppender and deprecate factory
method
and create another Jira after that.
Gary
On Mon, Sep 12, 2016 at 8:05 PM, Ralph Goers <ralph.go...@dslextreme.com>
wrote:
> After reviewing what I wrote below and looking at the Routing Appender I
> think the best thing to do is just to add script support to it. It already
> has support for a default Route. The init script, if present, could
> override which Route to use as I described below. Then we could add a
> script attribute to the Routes plugin which could be used to select the
> Route instead of only matching on the ThreadContext key.
>
> With that I think you would have everything you want, plus it could be
> used as a more intelligent way to route to existing appenders.
>
> The configuration would then look like:
>
> <Appenders>
> <Console name="STDOUT" target="SYSTEM_OUT">
> <PatternLayout pattern="%m%n"/>
> </Console>
> <Flume name="AuditLogger" compress="true">
> <Agent host="192.168.10.101" port="8800"/>
> <Agent host="192.168.10.102" port="8800"/>
> <RFC5424Layout enterpriseNumber="18060" includeMDC="true"
> appName="MyApp"/>
> </Flume>
> <Routing name=?Routing?>
> <InitScript name=?RoutingInit" language="groovy"><![CDATA[ if
> (System.getProperty(?os.name?).contains(?OS/390") { return
> “OS390"; } return null;]]>
> </InitScript>
> <Routes>
> <Script name="Router" language="groovy"><![CDATA[ if
> (logEvent.getMarker() != null && logEvent.getMarker().isInstanceOf("AUDIT"))
> { return "AUDIT"; } else if
> (logEvent.getContextMap().containsKey("UserId")) { return
> logEvent.getContextMap().get("UserId"); } return
> "STDOUT"; ]]>
> </Script>
> <Route>
>
> <OS390Appender name=“OS390-${mdc:UserId”/>
> <RollingFile name="Rolling-${mdc:UserId}"
> fileName="${mdc:UserId}.log"
> filePattern="${mdc:UserId}.%i.log.gz">
> <PatternLayout>
> <pattern>%d %p %c{1.} [%t] %m%n</pattern>
> </PatternLayout>
> <SizeBasedTriggeringPolicy size="500" />
> </RollingFile>
> </Route>
> <Route ref="AuditLogger" key="Audit"/>
> <Route ref="STDOUT" key="STDOUT"/>
> </Routes>
> <IdlePurgePolicy timeToLive="15" timeUnit="minutes"/>
> </Routing>
> </Appenders>
>
> First, the init script changes the default route based on the OS.
> Second, notice that “Routes” has a new Script element and does not have a
> pattern specified, so the script is determining the key instead of the
> pattern.
> Third, the real default route is now “STDOUT” since the actual default
> Route is only referenced when a UserId is present in the thread context map.
>
> What would also be nice is if there was a way to have the returned value
> be usable as a Lookup value in the default Appender definition, instead of
> relying on the MDC as the code above does. I should be able to pick
> something out of the message itself and use that as the key. That should be
> doable but I am still pondering how I would implement that.
>
> Ralph
>
>
>
> On Sep 12, 2016, at 6:06 PM, Ralph Goers <ralph.go...@dslextreme.com>
> wrote:
>
> I’ll try to describe it better but I’m not sure how good a job I’ll do if
> the dots aren’t clicking yet. Also, even though I might say to do it one
> way if I was coding I could very well change my mind as I implement it.
> That said:
>
> 1. Create an Appender plugin named ScriptSelector or
> ScriptAppenderSelector. It needs the following parameters
> - name, a String PluginAttribute
> - default, a String PluginAttribute
> - initScript or startupScript, an AbstractScript PluginElement
> - script, an AbstractScript PluginElement
> - appenderList, an AppenderList PluginElement.
> 2. As always, the builder (or factory) creates an instance of the
> ScriptAppenderSelector.
> - If there is an init script then the builder (or factory) executes
> it.
> - If the returned value is not null then instantiate the Appender
> with that name using the configuration in the AppenderList.
> - Whatever Appender the init script names should become the default
> Appender.
> - If no init script is present or the init script returns null use
> the value of the default setting as the name of the default Appender to
> use.
> - Create the default Appender and save it in the Map of created
> appenders wrapped by an AppenderControl.
> 3. When the append method is called check for a script setting.
> - If a script is found, run it.
> - If it returns a value see if that appender is saved in the
> AppenderMap.
> - If it is, call the appender and return.
> - If it is not, locate the configuration for the appender,
> create it and add it to the AppenderMap. Then call it and return.
> - If it returns null or no script is defined then call the default
> Appender and return.
> 4. When the stop method is called call the stop method on each of the
> Appenders in the AppenderMap.
>
>
> Note that signatures for scripts are defined by the components that use
> them. In this case both the init script and script return the name of the
> appender to execute.
>
> Ralph
>
>
> On Sep 12, 2016, at 12:54 PM, Gary Gregory <garydgreg...@gmail.com> wrote:
>
> On Sun, Sep 11, 2016 at 12:47 PM, Ralph Goers <ralph.go...@dslextreme.com>
> wrote:
>
>> Yes. The Appenders tag inside the ScriptSelector are the Appenders that
>> are to be created. But now that I think about it, we can’t use “Appenders”
>> for this. If you look at the RoutingAppender you will notice that Appenders
>> there are declared under a Route element. The Route plugin is defined with
>> deferChildren=true. This means that whatever is configured under the Route
>> will not be created during initial configuration. Instead the Route keeps a
>> reference to the Node and then configures the Appender when it is required.
>> So we would need a new plugin to wrap the Appenders that are to be created.
>>
>
> Can you please describe in more detail how this new plug fits in and what
> it does? I can't quite connect the dots with the parallel of the routing
> appender. I'm willing to implement this as I need the feature ASAP.
>
> Gary
>
>
>> Ralph
>>
>> On Sep 11, 2016, at 11:10 AM, Gary Gregory <garydgreg...@gmail.com>
>> wrote:
>>
>> Are the <Appenders> tags really meant to be nested?
>>
>> Gary
>>
>> On Sat, Sep 10, 2016 at 11:48 AM, Ralph Goers <ralph.go...@dslextreme.com
>> > wrote:
>>
>>> Oops. I forgot the closing CDATA tag in the script.
>>>
>>> Ralph
>>>
>>> On Sep 10, 2016, at 11:43 AM, Ralph Goers <ralph.go...@dslextreme.com>
>>> wrote:
>>>
>>> Interesting. OS/390. I worked on MVS, OS/370, z/OS, etc many moons ago
>>> but haven’t worked on a mainframe since 2001.
>>>
>>> This sort of sounds like you want an Appender Selector, which would be
>>> an Appender that uses a Selector to figure out which Appender to delegate
>>> to. This is a bit like the PatternSelector. I would imagine it would make
>>> sense to implement AppenderSelectors and LayoutSelectors. You probably
>>> would want to dynamically initialize the Appenders much like the
>>> RoutingAppender does.
>>>
>>> Maybe it would look like:
>>>
>>> <Appenders>
>>> <ScriptSelector name=“" default=“”>
>>> <Script language=“groovy”><