Re: Issue after moving to log4j 2.19

Hi Joan,

On Sun, 16 Oct 2022 at 00:45, Joan ventusproxy
<[email protected]> wrote:
> The " log4j.configurationFile " variable is set in this way:
> System.setProperty("log4j.configurationFile", "/opt/ventusproxy/app/proxy/ROOT/WEB-INF/log4j.xml");

For some unknown reason this is executed too late (after Log4j2
configuration). In the second file you posted you can see that Log4j2
is initialized twice: the first time the logger context associated
with your web app's classloader  picks up the default configuration,
because no `log4j2.configurationFile` setting is visible. Then
`log4j-web` configures what seems to be a second logger context with
your configuration (but `log4j-web` uses the `ServletContext` init
params to retrieve the configuration).

To find which component calls Log4j2 before `log4j-web` you can use
`-Dlog4j2.loggerContextStacktraceOnStart=true`. The web fragment
`log4j` contained in `log4j-web` requests to be executed before all
others, but you can change it with `<absolute-ordering>` in your
`web.xml`.

> And tomcat starts with:
> -DLog4jContextSelector=org.apache.logging.log4j.core.async.AsyncLoggerContextSelector

This setting basically breaks `log4j-web` ("WARN StatusLogger
Potential problem: Selector is not an instance of
NamedContextSelector."). Look into your web application descriptor and
remove the `isLog4jContextSelectorNamed` parameter. You can also use
the `BasicAsyncLoggerContextSelector` which always selects a thread
bound logger context (`log4j-web` manages the thread binding).

Piotr