I've managed to find a solution that works. The info I found has me using the "log4j-jul" bridge (and excluding spring-boot-starter-logging from spring-boot-starter-web), which redirects from jul to log4j, which effectively redirects to logback, which allows me to configure loggers in the same place as my other loggers, in the logback.xml file. I haven't yet verified this with the Tomcat startup error I was looking at (that was apparently resolved in some other way), but I've verified that I can see other log messages from StandardContext, so it's pretty likely this will work.
On Sat, Apr 19, 2025, 11:49 AM KARR, DAVID <dk0...@att.com> wrote: > This is an issue I've tried to pursue multiple times in the past, and each > time I've given up and used an awkward solution that won't work in the > current situation I'm seeing this. I thought perhaps I had asked it here > before, but I don't see it in the archives. > > We have a couple hundred Java SpringBoot services, most of them using > SpringBoot 3.2.5. Internally, it is using Tomcat through the > "tomcat-embed-core" artifact, version 10.1.30. > > Every once in a while, I run into a problem where the service startup > fails with some variation of this: > > WebServerException: Unable to start embedded Tomcat > > The stacktrace provided in this case has no stack entries in application > code. It provides no clue of what actually went wrong. Whenever I run into > this, if I can run the service on my desktop, I set breakpoints in the > StandardContext class wherever it sets "ok" to false. That always leads to > the solution. It almost always points to a conflict with dependencies, but > knowing that fact doesn't help me until I know what the conflict is. > > I really shouldn't have to do this. I can clearly see in the > StandardContext class that it tries to log the exception message (usually a > "MultiException" or something like that). Ideally, I should just be able to > configure the logging for tomcat-embed-core to make it print the exception > details. Several times I have struggled to make this work, and I've never > been able to get it working. Tomcat uses java.util.logging, but it seems to > have some variations that seemingly make it more difficult to configure. > I've tried variations with a "logging.properties" file, but it never seems > to make any difference. I've seen some posts that try to address this, but > I've never found a complete solution for getting this working in a > SpringBoot application. > > In the latest instance, I'm seeing this happen in an environment I can't > run the debugger in, so I have no way to diagnose this. > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > For additional commands, e-mail: users-h...@tomcat.apache.org > >
