[jboss-jira] [JBoss JIRA] (WFCORE-3210) Wildfly module isolation not working consistently

[Nuno Godinho de Matos (JIRA)]

    [ https://issues.jboss.org/browse/WFCORE-3210?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13459079#comment-13459079 ] 

Nuno Godinho de Matos commented on WFCORE-3210:
-----------------------------------------------

Hi James,

You are right that I have tried to explain what the issue that is taking place is.
- I have tried to convey multiple times that:
There must be an issue with module system or with my module configuration. Because if modules can conceptually be isolated from one another; and since the custom appenders are searched within "custom" modules; then these custom modules, like my own module, should be able to 100% isolated from the jboss log4j, 100% of the time.
- which seems not to be the case whenever i start widlfly for the first time, or switch around my way of starting wildfly. 
This i have tried to explain many many times as you point out.

But then, I have also tried to convey the business use case for this.
- We have our own log4j 1 appenders - that we normally use at application server level not at deployment level. 
- We do not want to be configuring logging per deployment. 
- In fact, we want more than the logging of an invididual application, we want all logging events.  Such as Warnings loged by background monitoring threads of ActiveMq, or any such stuff we do not demploy but that logs important relevant information . 
- But because our appenders are not JDK appenders   (obviously)
-- To note be politically correct here:
-- Java util logging API is simply the worst logging API on the planet. And if it is not it is close to it. It is broken from the day it was created. Everything that could go wrong there went wrong. The lack of thread name, the thread id as an integer, no MDC concept, everything is missing there, and what is in is bad. So we would never have chosen JUL as the base for our appenders at the point when they were written.
- We want to use these appenders.

NOTE:
- Conceptually, I could rewrite every single one of my appenders as Java Util appender because on Wildfly offers a LogRecord extension class that has all the good proper information in there that you do not have on pure JUL. But agaub that is not JDK standard that is wildfly specific goodies. To rewrite all of these appenders would be quite a bit of effort. And if conceptually I do not need to this because the module subsystem allows me to escape this effort, why would I do it?

What I am trying to do, I believe, is conceptually trivial. - It is just trying to make JUL appender that routes to Log4j work 100% of the time. And if module isolation is working 100% stable - this should be possible.


As always.
Many thanks.

> Wildfly module isolation not working consistently
> -------------------------------------------------
>
>                 Key: WFCORE-3210
>                 URL: https://issues.jboss.org/browse/WFCORE-3210
>             Project: WildFly Core
>          Issue Type: Bug
>          Components: Logging, Modules
>    Affects Versions: 2.2.0.Final
>            Reporter: Nuno Godinho de Matos
>
> There is an underministic bug on the module layer of wildfly, whereby the boot logic of the application server is not ensured to give the appropriate module isolation - which can lead to unexpected boot classpath problems.
> An example of this phenomena is given on the wildfly forum thread:
> https://developer.jboss.org/thread/275839
> In this example, we have the logging subsystem setup to use a custome handler.
> The custom handler wishes to have acces to the JUL extension classes on the org.jboss.logmanger module, but wishes to do have no relationship with the org.apache.log4j packages associated to the wildfly org.jboss.log4j module.
> What we see in this example is that an application gets from wildfly mixed behavior.
> Most of the time, during boot, the processes works without problem, where the custom handler runs isolated from the undersired log4j libraries within wildfly.
> But other times the application boot procedure will not go smoothly with the custom handler having processes routing JUL LogRecords events into the bundled log4j because the application server has loaded some of the classes that exist the org.jboss.log4j module.
> And as we know when the same class is loaded by different class loaders, then that class that orinates from class loader A cannot be assigned to the corresponding class of class loader B, even if the classes are exactly the same.
> This is not an isolated issue.
> There are also open issues on the wildfly forum reporting on startup problems on the logging subsystme where sometimes the LogManager class had not yet been loaded, and sometimes this issue goes away.
> This is an indication of some deep issue engrained into the module loading, where the module isolation behavior is not ensured to work all the time and that the boot procedure is not deterministically reliable. 
> It should not be that the application server some time starts successfully and others not.
> Booting wildfly should always result in the same outcode.
> Problems of this nature with class loading problems should either always happen if the configuration is not done properly or never happen if the configuration is proper.
> In the case of thread:
> https://developer.jboss.org/thread/275839
> Our belief is that the configuration is doing all it possible can to request the necessary module isolation from base packages and the outcome where log4j class load problems take place should never be allowed to happen.
> Many thanks.



--
This message was sent by Atlassian JIRA
(v7.2.3#72005)