I've been trying to track down some HTTP 500s being sent by my application. They appear as so in the localhost_access_log.txt:
127.0.0.1 - - [30/Aug/2017:16:27:46 +0000] "POST /user/174 HTTP/1.1" 500 1
So I added logging to my application, to catch all exceptions and responses of type 5xx. These logs are never populated. Plus, as you can see, the length of the response is one byte, which should never be the case. The web framework I am using, Lift, will return larger responses than that with a 5xx.
I am trying to catch all issues as so:
LiftRules.onEndServicing.append {
case (req, Full(resp)) => {
resp.toResponse.code.toString match {
case internalServerError if(internalServerError.startsWith("5")) => requestLogError(req, resp.toString)
case _ =>
}
}
case _ =>
}
LiftRules.exceptionHandler.prepend {
case (runMode, req, exception) =>
requestLogError(req, Throwables.getStackTraceAsString(exception))
XhtmlResponse((<html> <body>Something unexpected happened while serving the page at {req.uri}</body> </html>), S.htmlProperties.docType, List("Content-Type" -> "text/html; charset=utf-8"), Nil, 500, S.legacyIeCompatibilityMode)
}
So as there's nothing being logged in the requestLog I wonder if it's even hitting my code.
How can I enable better logging in Tomcat to see the underlying cause?
There's nothing in catalina.out either.
errors of type 5xx are indications of unexpected errors on the server. Ideally, developer should put all possible try-catch blocks within the code so that these 5xx error don't happen. On the same note, try to catch all types of errors rather than looking out for specific 5xx errors within the code, else these logs would never get logged.