Ok,
Didn't test it (it is started with suspend='n').
Just didn't know what the option was exactly doing, hence the question.
J.P.
-----Original Message-----
From: Mark Thomas <ma...@apache.org>
Sent: maandag 13 juni 2022 14:58
To: users@tomcat.apache.org
Subject: Re: Debugging Tomcat during shutdown
On 10/06/2022 07:19, Jean Pierre URKENS wrote:
> Could it depend on whether 'suspend=n' or 'suspend=y' is set on the
> jdwp options?
I haven't tested that. Have you?
My expectation is that it wouldn't have an impact since that option just
suspends the VM on start until the debugger attaches. I don't see any reason
why that would impact behaviour during JVM shutdown.
Mark
>
> JP
> -----Original Message-----
> From: Mark Thomas <ma...@apache.org>
> Sent: woensdag 8 juni 2022 14:50
> To: users@tomcat.apache.org
> Subject: Re: Debugging Tomcat during shutdown
>
> On 08/06/2022 13:39, Jean Pierre URKENS wrote:
>> Indeed the servlet#destroy() method is called.
>>
>> That is however not the issue I was troubleshooting, I just mentioned
>> it as an example of a method I can't debug since the debug session is
>> killed before hitting the servlet#destroy() method.
>
> I can't recreate that problem. I have tested with 10.1.x, 8.5.x and
> 8.5.43 and in all cases, as long as I make sure a servlet has been
> loaded, execution stops at the breakpoint I have set.
>
>> What I am actually was trying to troubleshoot is spring context
>> cleanup which seems to happen after the servlet cleanups. Here e.g.
>> the stacktrace I was tackling:
>>
>> java.lang.NullPointerException
>>
>> at
>> java.util.concurrent.ConcurrentHashMap.replaceNode(ConcurrentHashMap.
>> j
>> ava:1106)
>
> <snip/>
>
>> In the meantime I know why the NPE occurs, but it bothered me that I
>> couldn’t debug through it (debug session got killed before hitting
>> any breakpoint I activated, e.g. in Serverimpl#stop()).
>
> That is odd. I'd expect the debug session to be active as long as the
> JVM was running.
>
> One thing you could try is adding an additional breakpoint to the
> finally block in StandardServer.await(). That should allow you to
> control the shutdown process.
>
> A final thought. Are you sure you have the right source code in your IDE?
> While RHEL may based Tomcat 8.5.x on 8.5.43 they will have back-ported
> security and other fixes so the 8.5.43 source code from the ASF is
> unlikely to be a prefect match to what you have running. Often you can
> get away with it, but sometimes I have had issues with breakpoints not
> activating because I was using the wrong source code.
>
> Glad you fixed the NPE anyway.
>
> Mark
>
>
>>
>>
>>
>> -----Original Message-----
>> From: Mark Thomas <ma...@apache.org>
>> Sent: woensdag 8 juni 2022 14:23
>> To: users@tomcat.apache.org
>> Subject: Re: Debugging Tomcat during shutdown
>>
>>
>>
>> On 08/06/2022 11:54, Jean Pierre URKENS wrote:
>>
>>> Hi Mark,
>>
>>>
>>
>>> I know the version is quite old, but that is what the client
>>> currently
>>
>>> has installed.
>>
>>
>>
>> ACK.
>>
>>
>>
>>> I am shutting Tomcat down with ${TOMCAT_HOME}/bin/shutdown.sh (RHEL
>>
>>> 7.x server).
>>
>>
>>
>> Good. I think that is likely to be the best option in this case.
>>
>>
>>
>>> We've got TOMCAT_HOME under '/opt/tomcat8' and several TOMCAT_BASE
>>
>>> server instances.
>>
>>
>>
>> When you say servlet clean-up actions, what exactly do you mean? The
>>
>> Servlet.destroy() method?
>>
>>
>>
>> Generally, I'd recommend a ServletContextListener for resource clean-up.
>>
>> Partly that is personal preference - I find it cleaner if all the
>> code is in one place - and partly it is avoiding potential issues
>> around containers destroying unused servlets while the web app is
>> running.
>> Most
>>
>> (all) containers won't do this but you never know.
>>
>>
>>
>> Meanwhile, I'm planning on some local testing to see if I can
>> recreate the issue you are seeing.
>>
>>
>>
>> Mark
>>
>>
>>
>>
>>
>>>
>>
>>> J.P.
>>
>>>
>>
>>>
>>
>>>
>>
>>> -----Original Message-----
>>
>>> From: Mark Thomas <ma...@apache.org>
>>
>>> Sent: woensdag 8 juni 2022 12:45
>>
>>> To: users@tomcat.apache.org
>>
>>> Subject: Re: Debugging Tomcat during shutdown
>>
>>>
>>
>>> On 08/06/2022 11:29, Jean Pierre URKENS wrote:
>>
>>>> I am trying to debug the cleanup of resources during a shutdown of
>>
>>>> Tomcat
>>
>>>> 8.5.43
>>
>>>
>>
>>> That is a rather old version. I'd recommend upgrading.
>>
>>>
>>
>>>> and notices that my debug session gets killed prior to performing
>>>> any
>>
>>>> servlet cleanup actions.
>>
>>>>
>>
>>>> I am starting Tomcat in debug mode with the JVM options:
>>
>>>>
>>
>>>> JAVA_OPTS="$JAVA_OPTS -Xdebug
>>
>>>> -Xrunjdwp:transport=dt_socket,address=xxxx,server=y,suspend=n"
>>
>>>>
>>
>>>> Is this normal behavior? How do I debug tomcat in this scenario.
>>
>>>
>>
>>> How are you triggering shutdown?
>>
>>>
>>
>>> Mark
>>
>>>
>>
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>>
>>
>>
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