Re: internal server error

["Craig R. McClanahan" <cr...@apache.org>]

On Tue, 28 Aug 2001, Scott Knight wrote:

> Date: Tue, 28 Aug 2001 08:23:05 -0400
> From: Scott Knight <sc...@loanprotector.com>
> Reply-To: tomcat-user@jakarta.apache.org
> To: tomcat-user@jakarta.apache.org
> Subject: internal server error
>
> 	I have a question that hopefully someone on this list can help with. I use
> the startup.sh and shutdown.sh scripts to start and stop tomcat. If i stop
> tomcat and then bring it back up and go and try to view a servlet I get an
> internal server error from apache, like tomcat really isnt up yet or
> something. But if i then hit refresh on my brower like 7 or 8 times tomcat
> will start responding like normal. I saw a message on the same topic of
> this in the mail archives but I didnt see a definite answer. Anyone know
> why this is? And is there any way to stop this?
>

Without details of the server components you are running (Apache version?
Tomcat version?) and the actual servlet being tested, and the *actual*
error messages and/or stack traces you are receiving, it is impossible for
*anyone* to give you any substantive help on this.

> Second question is about auto reloading. I use ant to create my war files
> so they are of the standard directory layout. After tomcat starts and
> unpacks the war I should be able to copy recompiled classes into the
> MyProject/WEB-INF/classes directory and have tomcat auto reload (server.xml
> says that auto reload is default to true ) This works most of the time. But
> sometimes i swear it wont reload my servlet until i stop tomcat, remove the
> unpacked war directory and restart tomcat. This doesn't make any sense to me?
>

What Tomcat are you running?  Tomcat 3.2.x has lots of problems
recognizing updated classes that are not themselves servlets -- Tomcat 4.0
fixes this particular issue.

> Also one last semi related question. Can someone tell me how tomcat decides
> what servlets to cache in memory?

*All* Java classes that are your servlets (or are referenced by your
servlets) are loaded once by the appropriate class loader.  This is a Java
thing, not a Tomcat thing.

> If it is really auto reloaded servlets,
> if i delete all my class files i shouldnt be able to get to any servlets
> correct?

No.  If you have referenced a particular class *once*, it will have
already been loaded into the JVM.  The existence or non-existence of the
".class" file where this class was loaded from is not relevant.

> But i have deleted all my class files and still can get to certain
> servlets in my web app. So how does tomcat choose what servlets to cache or
> not?
>
> Any and all information that can help with these three questions would be
> greatly apprecaited. Thanks in advance.
>
> 	Scott Knight
>
>
Craig