Re: AW: AW: Tomcat 9 doesn't shutdown cleanly
Hi, > Hello Simon, > > if you use the Registry to bind Objects / Stubs, you must also call > "unbind" on shutdown: > https://docs.oracle.com/javase/7/docs/api/java/rmi/registry/Registry.html > > I think the developer who implemented the RMI stub, should also now what > to unbind. > > Greetings, > Thomas The issue has been solved now by adding two unbind() where they were clearly missing. Tomcat shuts down cleanly now with no delay. Thanks to all who helped! Regards, Simon - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Tomcat 9 doesn't shutdown cleanly
On 11/30/2021 8:40 AM, Simon Matter wrote:
Hi Chris,
Thank you for the quick reply.
Simon,
On 11/30/21 08:21, Simon Matter wrote:
I'm running an application on Tomcat 9.0.55 on x86_64 Linux with OpenJDK
JRE-11.0.13+8 and have problems shutting down Tomcat in certain ways.
When I shutdown Tomcat via 'catalina.sh stop', it shuts down mostly
(most
threads are gone) but send a thread dump to catalina.out and is later
killer by an OS signal.
This should only happen if you have CATALINA_PID defined. Are you indeed
defining that environment variable?
catalina.sh has this code in it, which is probably what you are seeing:
echo "To aid diagnostics a thread dump has been written to
standard out."
kill -3 `cat "$CATALINA_PID"`
That's true, I have CATALINA_PID defined when the call of "catalina.sh
start" is done. So yes, the script will kill the java process if it
doesn't terminate.
When shutting down Tomcat via the shutdown listener on port 8005, it
also
shuts down mostly but without the thread dump in catalina.out. Sending
SIGTERM later to the still running java process terminates it.
Right: when you manually connect to the shutdown port and send
"SHUTDOWN" (or whatever), it asks Tomcat to shut down but doesn't send a
signal. You have to do that manually, too.
On a test host, when I send "SHUTDOWN" to the shutdown listener, Tomcat
shuts down and the Java VM terminates.
Only on this host with the application, when I send "SHUTDOWN" to the
shutdown listener, Tomcat shuts down but the Java VM doesn't terminate.
So both methods somehow terminate Tomcat partly but not completely.
You have one or two of the following issues:
1. You have a non-daemon thread running
2. You have an unusually long shutdown process that just takes "too long"
The good news is that the thread-dup can answer that question: what's in
the thread dump that is generated when you run "catalina.sh stop"?
When simply sending SIGTERM on the OS level, Tomcat shuts down cleanly
and
terminates without issues.
One thing in common is that I always see these messages while shutting
down:
30-Nov-2021 13:59:36.985 SEVERE [main]
org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesRmiTargets
Found RMI Target with stub class class
[sun.rmi.registry.RegistryImpl_Stub] and value
[RegistryImpl_Stub[UnicastRef [liveRef:
[endpoint:[157.161.91.47:2071](local),objID:[0:0:0, 0]. This RMI
Target has been forcibly removed to prevent a memory leak.
30-Nov-2021 13:59:36.987 SEVERE [main]
org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesRmiTargets
Found RMI Target with stub class class [com.sun.proxy.$Proxy51] and
value
[Proxy[ShopdbCacheSynchronizer,RemoteObjectInvocationHandler[UnicastRef
[liveRef:
[endpoint:[157.161.91.47:1096](local),objID:[-6f4b2f9d:17d70eb1ef4:-7ffd,
-4005526521234186948]]. This RMI Target has been forcibly removed to
prevent a memory leak.
30-Nov-2021 13:59:36.987 SEVERE [main]
org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesRmiTargets
Found RMI Target with stub class class
[sun.rmi.registry.RegistryImpl_Stub] and value
[RegistryImpl_Stub[UnicastRef [liveRef:
[endpoint:[157.161.91.47:1096](local),objID:[0:0:0, 0]. This RMI
Target has been forcibly removed to prevent a memory leak.
Why do the three methods to shutdown Tomcat differ and how can I make
'catalina.sh stop' or the shutdown listener work the same way like
sending
the OS signal.
What's the difference? You don't want the thread dump in your
catalina.out? That's supposed to be helpful in debugging why your
shutdown isn't clean. It sounds like you are saying "help me with my
unclean shutdown; please get rid of the debugging information that is
trying to help me!".
I've tried, beside a lot of other things, to set
skipMemoryLeakChecksOnJvmShutdown="true" in context.xml but it seems to
change nothing at all.
Tomcat will never kill your non-daemon thread(s) from inside the VM.
Since you are using a CATALINA_PID environment variable (and, therefore,
a pid-file), the shutdown process is sending the TERM signal. It's also
possibly sending a KILL signal, depending on whether or not the TERM
worked and if -force was supplied on the command-line.
Unfortunately I am not an insider when it comes to Java, so I'm not sure
what a non-daemon thread means here? Can these be threads started by our
application which are non-daemon threads? So they will be terminated with
SIGTERM to the Java VM but not using the shutdown listener?
I'll paste a thread dump below.
Thanks,
Simon
Full thread dump OpenJDK 64-Bit Server VM (11.0.13+8 mixed mode):
Threads class SMR info:
_java_thread_list=0x55a49ac4ba60, length=18, elements={
0x7f1ac0148800, 0x7f1ac014a800, 0x7f1ac015f800,
0x7f1ac0161800,
0x7f1ac0164000, 0x7f1ac0168800, 0x7f1ac016a000,
0x7f1ac01ad800,
0x7f1ac0258000, 0x7f1ac0311000, 0x7f1ac0318000,
0x7f1ac031a000,
0x7f1ac25d6800, 0x7f1ac25fe800,
AW: AW: Tomcat 9 doesn't shutdown cleanly
Hello Simon, if you use the Registry to bind Objects / Stubs, you must also call "unbind" on shutdown: https://docs.oracle.com/javase/7/docs/api/java/rmi/registry/Registry.html I think the developer who implemented the RMI stub, should also now what to unbind. Greetings, Thomas -Ursprüngliche Nachricht- Von: Simon Matter Gesendet: Dienstag, 30. November 2021 16:10 An: Tomcat Users List Betreff: Re: AW: Tomcat 9 doesn't shutdown cleanly Hi Thomas, > Hello, > > it looks like your application opens several ports for RMI communication. > One class is mentioned in your first mail: ShopdbCacheSynchronizer Yes, and it's true that when I'm looking at the shut down Tomcat instance VM, I see several RMI threads lingering around. > > Maybe you can ask the developer guys to check whether these threads / > ports are terminated / closed cleanly on shutdown event. > Quite often developers don't care much about shutting down their stuff > cleanly. Good guess, that's exactly what I'm trying to do, finding out why we have the shutdown problems so the "developer guys" can finally fix this issue. From how I understand it, we have an internal application server which initiates RMI connections to the Tomcat instance sitting in the DMZ. My question is, can we terminate the RMI connections on the Tomcat instance only and shut down Tomcat, or do we have to close the RMI connections on the internal appserver which initiated the connections? Apart from RMI, is there anything in the thread dump which indicates an issue in out Tomcat app? Kind regards, Simon > > Greetings, > Thomas > > -Ursprüngliche Nachricht- > Von: Simon Matter > Gesendet: Dienstag, 30. November 2021 15:40 > An: Tomcat Users List > Betreff: Re: Tomcat 9 doesn't shutdown cleanly > > Hi Chris, > > Thank you for the quick reply. > >> Simon, >> >> On 11/30/21 08:21, Simon Matter wrote: >>> I'm running an application on Tomcat 9.0.55 on x86_64 Linux with >>> OpenJDK >>> JRE-11.0.13+8 and have problems shutting down Tomcat in certain ways. >>> >>> When I shutdown Tomcat via 'catalina.sh stop', it shuts down mostly >>> (most threads are gone) but send a thread dump to catalina.out and >>> is later killer by an OS signal. >> >> This should only happen if you have CATALINA_PID defined. Are you >> indeed defining that environment variable? >> >> catalina.sh has this code in it, which is probably what you are seeing: >> >>echo "To aid diagnostics a thread dump has been written to >> standard out." >>kill -3 `cat "$CATALINA_PID"` >> > > That's true, I have CATALINA_PID defined when the call of "catalina.sh > start" is done. So yes, the script will kill the java process if it > doesn't terminate. > >>> When shutting down Tomcat via the shutdown listener on port 8005, it >>> also shuts down mostly but without the thread dump in catalina.out. >>> Sending SIGTERM later to the still running java process terminates >>> it. >> >> Right: when you manually connect to the shutdown port and send >> "SHUTDOWN" (or whatever), it asks Tomcat to shut down but doesn't >> send a signal. You have to do that manually, too. > > On a test host, when I send "SHUTDOWN" to the shutdown listener, > Tomcat shuts down and the Java VM terminates. > > Only on this host with the application, when I send "SHUTDOWN" to the > shutdown listener, Tomcat shuts down but the Java VM doesn't terminate. > >> >>> So both methods somehow terminate Tomcat partly but not completely. >> >> You have one or two of the following issues: >> >> 1. You have a non-daemon thread running 2. You have an unusually long >> shutdown process that just takes "too long" >> >> The good news is that the thread-dup can answer that question: what's >> in the thread dump that is generated when you run "catalina.sh stop"? >> >>> When simply sending SIGTERM on the OS level, Tomcat shuts down >>> cleanly and terminates without issues. >>> >>> One thing in common is that I always see these messages while >>> shutting >>> down: >>> >>> 30-Nov-2021 13:59:36.985 SEVERE [main] >>> org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesRmiT >>> a rgets Found RMI Target with stub class class >>> [sun.rmi.registry.RegistryImpl_Stub] and value >>> [RegistryImpl_Stub[UnicastRef [liveRef: >>> [endpoint:[157.161.91.47:2071](local),objID:[0:0:0, 0]. This RMI >&g
Re: AW: Tomcat 9 doesn't shutdown cleanly
Hi Thomas, > Hello, > > it looks like your application opens several ports for RMI communication. > One class is mentioned in your first mail: ShopdbCacheSynchronizer Yes, and it's true that when I'm looking at the shut down Tomcat instance VM, I see several RMI threads lingering around. > > Maybe you can ask the developer guys to check whether these threads / > ports are terminated / closed cleanly on shutdown event. > Quite often developers don't care much about shutting down their stuff > cleanly. Good guess, that's exactly what I'm trying to do, finding out why we have the shutdown problems so the "developer guys" can finally fix this issue. >From how I understand it, we have an internal application server which initiates RMI connections to the Tomcat instance sitting in the DMZ. My question is, can we terminate the RMI connections on the Tomcat instance only and shut down Tomcat, or do we have to close the RMI connections on the internal appserver which initiated the connections? Apart from RMI, is there anything in the thread dump which indicates an issue in out Tomcat app? Kind regards, Simon > > Greetings, > Thomas > > -Ursprüngliche Nachricht- > Von: Simon Matter > Gesendet: Dienstag, 30. November 2021 15:40 > An: Tomcat Users List > Betreff: Re: Tomcat 9 doesn't shutdown cleanly > > Hi Chris, > > Thank you for the quick reply. > >> Simon, >> >> On 11/30/21 08:21, Simon Matter wrote: >>> I'm running an application on Tomcat 9.0.55 on x86_64 Linux with >>> OpenJDK >>> JRE-11.0.13+8 and have problems shutting down Tomcat in certain ways. >>> >>> When I shutdown Tomcat via 'catalina.sh stop', it shuts down mostly >>> (most threads are gone) but send a thread dump to catalina.out and is >>> later killer by an OS signal. >> >> This should only happen if you have CATALINA_PID defined. Are you >> indeed defining that environment variable? >> >> catalina.sh has this code in it, which is probably what you are seeing: >> >>echo "To aid diagnostics a thread dump has been written to >> standard out." >>kill -3 `cat "$CATALINA_PID"` >> > > That's true, I have CATALINA_PID defined when the call of "catalina.sh > start" is done. So yes, the script will kill the java process if it > doesn't terminate. > >>> When shutting down Tomcat via the shutdown listener on port 8005, it >>> also shuts down mostly but without the thread dump in catalina.out. >>> Sending SIGTERM later to the still running java process terminates >>> it. >> >> Right: when you manually connect to the shutdown port and send >> "SHUTDOWN" (or whatever), it asks Tomcat to shut down but doesn't send >> a signal. You have to do that manually, too. > > On a test host, when I send "SHUTDOWN" to the shutdown listener, Tomcat > shuts down and the Java VM terminates. > > Only on this host with the application, when I send "SHUTDOWN" to the > shutdown listener, Tomcat shuts down but the Java VM doesn't terminate. > >> >>> So both methods somehow terminate Tomcat partly but not completely. >> >> You have one or two of the following issues: >> >> 1. You have a non-daemon thread running 2. You have an unusually long >> shutdown process that just takes "too long" >> >> The good news is that the thread-dup can answer that question: what's >> in the thread dump that is generated when you run "catalina.sh stop"? >> >>> When simply sending SIGTERM on the OS level, Tomcat shuts down >>> cleanly and terminates without issues. >>> >>> One thing in common is that I always see these messages while >>> shutting >>> down: >>> >>> 30-Nov-2021 13:59:36.985 SEVERE [main] >>> org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesRmiTa >>> rgets Found RMI Target with stub class class >>> [sun.rmi.registry.RegistryImpl_Stub] and value >>> [RegistryImpl_Stub[UnicastRef [liveRef: >>> [endpoint:[157.161.91.47:2071](local),objID:[0:0:0, 0]. This RMI >>> Target has been forcibly removed to prevent a memory leak. >>> 30-Nov-2021 13:59:36.987 SEVERE [main] >>> org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesRmiTa >>> rgets Found RMI Target with stub class class [com.sun.proxy.$Proxy51] >>> and value >>> [Proxy[ShopdbCacheSynchronizer,RemoteObjectInvocationHandler[UnicastR >>> ef >>> [liveRef: >>> [endpoint:[157.161.91.47:1096](local),objID:[-6f4b2f9d:17d
AW: Tomcat 9 doesn't shutdown cleanly
Hello, it looks like your application opens several ports for RMI communication. One class is mentioned in your first mail: ShopdbCacheSynchronizer Maybe you can ask the developer guys to check whether these threads / ports are terminated / closed cleanly on shutdown event. Quite often developers don't care much about shutting down their stuff cleanly. Greetings, Thomas -Ursprüngliche Nachricht- Von: Simon Matter Gesendet: Dienstag, 30. November 2021 15:40 An: Tomcat Users List Betreff: Re: Tomcat 9 doesn't shutdown cleanly Hi Chris, Thank you for the quick reply. > Simon, > > On 11/30/21 08:21, Simon Matter wrote: >> I'm running an application on Tomcat 9.0.55 on x86_64 Linux with >> OpenJDK >> JRE-11.0.13+8 and have problems shutting down Tomcat in certain ways. >> >> When I shutdown Tomcat via 'catalina.sh stop', it shuts down mostly >> (most threads are gone) but send a thread dump to catalina.out and is >> later killer by an OS signal. > > This should only happen if you have CATALINA_PID defined. Are you > indeed defining that environment variable? > > catalina.sh has this code in it, which is probably what you are seeing: > >echo "To aid diagnostics a thread dump has been written to > standard out." >kill -3 `cat "$CATALINA_PID"` > That's true, I have CATALINA_PID defined when the call of "catalina.sh start" is done. So yes, the script will kill the java process if it doesn't terminate. >> When shutting down Tomcat via the shutdown listener on port 8005, it >> also shuts down mostly but without the thread dump in catalina.out. >> Sending SIGTERM later to the still running java process terminates >> it. > > Right: when you manually connect to the shutdown port and send > "SHUTDOWN" (or whatever), it asks Tomcat to shut down but doesn't send > a signal. You have to do that manually, too. On a test host, when I send "SHUTDOWN" to the shutdown listener, Tomcat shuts down and the Java VM terminates. Only on this host with the application, when I send "SHUTDOWN" to the shutdown listener, Tomcat shuts down but the Java VM doesn't terminate. > >> So both methods somehow terminate Tomcat partly but not completely. > > You have one or two of the following issues: > > 1. You have a non-daemon thread running 2. You have an unusually long > shutdown process that just takes "too long" > > The good news is that the thread-dup can answer that question: what's > in the thread dump that is generated when you run "catalina.sh stop"? > >> When simply sending SIGTERM on the OS level, Tomcat shuts down >> cleanly and terminates without issues. >> >> One thing in common is that I always see these messages while >> shutting >> down: >> >> 30-Nov-2021 13:59:36.985 SEVERE [main] >> org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesRmiTa >> rgets Found RMI Target with stub class class >> [sun.rmi.registry.RegistryImpl_Stub] and value >> [RegistryImpl_Stub[UnicastRef [liveRef: >> [endpoint:[157.161.91.47:2071](local),objID:[0:0:0, 0]. This RMI >> Target has been forcibly removed to prevent a memory leak. >> 30-Nov-2021 13:59:36.987 SEVERE [main] >> org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesRmiTa >> rgets Found RMI Target with stub class class [com.sun.proxy.$Proxy51] >> and value >> [Proxy[ShopdbCacheSynchronizer,RemoteObjectInvocationHandler[UnicastR >> ef >> [liveRef: >> [endpoint:[157.161.91.47:1096](local),objID:[-6f4b2f9d:17d70eb1ef4:-7 >> ffd, -4005526521234186948]]. This RMI Target has been forcibly >> removed to prevent a memory leak. >> 30-Nov-2021 13:59:36.987 SEVERE [main] >> org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesRmiTa >> rgets Found RMI Target with stub class class >> [sun.rmi.registry.RegistryImpl_Stub] and value >> [RegistryImpl_Stub[UnicastRef [liveRef: >> [endpoint:[157.161.91.47:1096](local),objID:[0:0:0, 0]. This RMI >> Target has been forcibly removed to prevent a memory leak. >> >> Why do the three methods to shutdown Tomcat differ and how can I make >> 'catalina.sh stop' or the shutdown listener work the same way like >> sending the OS signal. > > What's the difference? You don't want the thread dump in your > catalina.out? That's supposed to be helpful in debugging why your > shutdown isn't clean. It sounds like you are saying "help me with my > unclean shutdown; please get rid of the debugging information that is > trying to help me!". > >> I've tried, beside a lot of other thing
Re: Tomcat 9 doesn't shutdown cleanly
Hi Chris,
Thank you for the quick reply.
> Simon,
>
> On 11/30/21 08:21, Simon Matter wrote:
>> I'm running an application on Tomcat 9.0.55 on x86_64 Linux with OpenJDK
>> JRE-11.0.13+8 and have problems shutting down Tomcat in certain ways.
>>
>> When I shutdown Tomcat via 'catalina.sh stop', it shuts down mostly
>> (most
>> threads are gone) but send a thread dump to catalina.out and is later
>> killer by an OS signal.
>
> This should only happen if you have CATALINA_PID defined. Are you indeed
> defining that environment variable?
>
> catalina.sh has this code in it, which is probably what you are seeing:
>
>echo "To aid diagnostics a thread dump has been written to
> standard out."
>kill -3 `cat "$CATALINA_PID"`
>
That's true, I have CATALINA_PID defined when the call of "catalina.sh
start" is done. So yes, the script will kill the java process if it
doesn't terminate.
>> When shutting down Tomcat via the shutdown listener on port 8005, it
>> also
>> shuts down mostly but without the thread dump in catalina.out. Sending
>> SIGTERM later to the still running java process terminates it.
>
> Right: when you manually connect to the shutdown port and send
> "SHUTDOWN" (or whatever), it asks Tomcat to shut down but doesn't send a
> signal. You have to do that manually, too.
On a test host, when I send "SHUTDOWN" to the shutdown listener, Tomcat
shuts down and the Java VM terminates.
Only on this host with the application, when I send "SHUTDOWN" to the
shutdown listener, Tomcat shuts down but the Java VM doesn't terminate.
>
>> So both methods somehow terminate Tomcat partly but not completely.
>
> You have one or two of the following issues:
>
> 1. You have a non-daemon thread running
> 2. You have an unusually long shutdown process that just takes "too long"
>
> The good news is that the thread-dup can answer that question: what's in
> the thread dump that is generated when you run "catalina.sh stop"?
>
>> When simply sending SIGTERM on the OS level, Tomcat shuts down cleanly
>> and
>> terminates without issues.
>>
>> One thing in common is that I always see these messages while shutting
>> down:
>>
>> 30-Nov-2021 13:59:36.985 SEVERE [main]
>> org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesRmiTargets
>> Found RMI Target with stub class class
>> [sun.rmi.registry.RegistryImpl_Stub] and value
>> [RegistryImpl_Stub[UnicastRef [liveRef:
>> [endpoint:[157.161.91.47:2071](local),objID:[0:0:0, 0]. This RMI
>> Target has been forcibly removed to prevent a memory leak.
>> 30-Nov-2021 13:59:36.987 SEVERE [main]
>> org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesRmiTargets
>> Found RMI Target with stub class class [com.sun.proxy.$Proxy51] and
>> value
>> [Proxy[ShopdbCacheSynchronizer,RemoteObjectInvocationHandler[UnicastRef
>> [liveRef:
>> [endpoint:[157.161.91.47:1096](local),objID:[-6f4b2f9d:17d70eb1ef4:-7ffd,
>> -4005526521234186948]]. This RMI Target has been forcibly removed to
>> prevent a memory leak.
>> 30-Nov-2021 13:59:36.987 SEVERE [main]
>> org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesRmiTargets
>> Found RMI Target with stub class class
>> [sun.rmi.registry.RegistryImpl_Stub] and value
>> [RegistryImpl_Stub[UnicastRef [liveRef:
>> [endpoint:[157.161.91.47:1096](local),objID:[0:0:0, 0]. This RMI
>> Target has been forcibly removed to prevent a memory leak.
>>
>> Why do the three methods to shutdown Tomcat differ and how can I make
>> 'catalina.sh stop' or the shutdown listener work the same way like
>> sending
>> the OS signal.
>
> What's the difference? You don't want the thread dump in your
> catalina.out? That's supposed to be helpful in debugging why your
> shutdown isn't clean. It sounds like you are saying "help me with my
> unclean shutdown; please get rid of the debugging information that is
> trying to help me!".
>
>> I've tried, beside a lot of other things, to set
>> skipMemoryLeakChecksOnJvmShutdown="true" in context.xml but it seems to
>> change nothing at all.
>
> Tomcat will never kill your non-daemon thread(s) from inside the VM.
> Since you are using a CATALINA_PID environment variable (and, therefore,
> a pid-file), the shutdown process is sending the TERM signal. It's also
> possibly sending a KILL signal, depending on whether or not the TERM
> worked and if -force was supplied on the command-line.
Unfortunately I am not an insider when it comes to Java, so I'm not sure
what a non-daemon thread means here? Can these be threads started by our
application which are non-daemon threads? So they will be terminated with
SIGTERM to the Java VM but not using the shutdown listener?
I'll paste a thread dump below.
Thanks,
Simon
Full thread dump OpenJDK 64-Bit Server VM (11.0.13+8 mixed mode):
Threads class SMR info:
_java_thread_list=0x55a49ac4ba60, length=18, elements={
0x7f1ac0148800, 0x7f1ac014a800, 0x7f1ac015f800,
0x7f1ac0161800,
0x7f1ac0164000, 0x7f1ac0168800,
Re: Tomcat 9 doesn't shutdown cleanly
Simon, On 11/30/21 08:21, Simon Matter wrote: I'm running an application on Tomcat 9.0.55 on x86_64 Linux with OpenJDK JRE-11.0.13+8 and have problems shutting down Tomcat in certain ways. When I shutdown Tomcat via 'catalina.sh stop', it shuts down mostly (most threads are gone) but send a thread dump to catalina.out and is later killer by an OS signal. This should only happen if you have CATALINA_PID defined. Are you indeed defining that environment variable? catalina.sh has this code in it, which is probably what you are seeing: echo "To aid diagnostics a thread dump has been written to standard out." kill -3 `cat "$CATALINA_PID"` When shutting down Tomcat via the shutdown listener on port 8005, it also shuts down mostly but without the thread dump in catalina.out. Sending SIGTERM later to the still running java process terminates it. Right: when you manually connect to the shutdown port and send "SHUTDOWN" (or whatever), it asks Tomcat to shut down but doesn't send a signal. You have to do that manually, too. So both methods somehow terminate Tomcat partly but not completely. You have one or two of the following issues: 1. You have a non-daemon thread running 2. You have an unusually long shutdown process that just takes "too long" The good news is that the thread-dup can answer that question: what's in the thread dump that is generated when you run "catalina.sh stop"? When simply sending SIGTERM on the OS level, Tomcat shuts down cleanly and terminates without issues. One thing in common is that I always see these messages while shutting down: 30-Nov-2021 13:59:36.985 SEVERE [main] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesRmiTargets Found RMI Target with stub class class [sun.rmi.registry.RegistryImpl_Stub] and value [RegistryImpl_Stub[UnicastRef [liveRef: [endpoint:[157.161.91.47:2071](local),objID:[0:0:0, 0]. This RMI Target has been forcibly removed to prevent a memory leak. 30-Nov-2021 13:59:36.987 SEVERE [main] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesRmiTargets Found RMI Target with stub class class [com.sun.proxy.$Proxy51] and value [Proxy[ShopdbCacheSynchronizer,RemoteObjectInvocationHandler[UnicastRef [liveRef: [endpoint:[157.161.91.47:1096](local),objID:[-6f4b2f9d:17d70eb1ef4:-7ffd, -4005526521234186948]]. This RMI Target has been forcibly removed to prevent a memory leak. 30-Nov-2021 13:59:36.987 SEVERE [main] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesRmiTargets Found RMI Target with stub class class [sun.rmi.registry.RegistryImpl_Stub] and value [RegistryImpl_Stub[UnicastRef [liveRef: [endpoint:[157.161.91.47:1096](local),objID:[0:0:0, 0]. This RMI Target has been forcibly removed to prevent a memory leak. Why do the three methods to shutdown Tomcat differ and how can I make 'catalina.sh stop' or the shutdown listener work the same way like sending the OS signal. What's the difference? You don't want the thread dump in your catalina.out? That's supposed to be helpful in debugging why your shutdown isn't clean. It sounds like you are saying "help me with my unclean shutdown; please get rid of the debugging information that is trying to help me!". I've tried, beside a lot of other things, to set skipMemoryLeakChecksOnJvmShutdown="true" in context.xml but it seems to change nothing at all. Tomcat will never kill your non-daemon thread(s) from inside the VM. Since you are using a CATALINA_PID environment variable (and, therefore, a pid-file), the shutdown process is sending the TERM signal. It's also possibly sending a KILL signal, depending on whether or not the TERM worked and if -force was supplied on the command-line. -chris - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Tomcat 9 doesn't shutdown cleanly
Hi, I'm running an application on Tomcat 9.0.55 on x86_64 Linux with OpenJDK JRE-11.0.13+8 and have problems shutting down Tomcat in certain ways. When I shutdown Tomcat via 'catalina.sh stop', it shuts down mostly (most threads are gone) but send a thread dump to catalina.out and is later killer by an OS signal. When shutting down Tomcat via the shutdown listener on port 8005, it also shuts down mostly but without the thread dump in catalina.out. Sending SIGTERM later to the still running java process terminates it. So both methods somehow terminate Tomcat partly but not completely. When simply sending SIGTERM on the OS level, Tomcat shuts down cleanly and terminates without issues. One thing in common is that I always see these messages while shutting down: 30-Nov-2021 13:59:36.985 SEVERE [main] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesRmiTargets Found RMI Target with stub class class [sun.rmi.registry.RegistryImpl_Stub] and value [RegistryImpl_Stub[UnicastRef [liveRef: [endpoint:[157.161.91.47:2071](local),objID:[0:0:0, 0]. This RMI Target has been forcibly removed to prevent a memory leak. 30-Nov-2021 13:59:36.987 SEVERE [main] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesRmiTargets Found RMI Target with stub class class [com.sun.proxy.$Proxy51] and value [Proxy[ShopdbCacheSynchronizer,RemoteObjectInvocationHandler[UnicastRef [liveRef: [endpoint:[157.161.91.47:1096](local),objID:[-6f4b2f9d:17d70eb1ef4:-7ffd, -4005526521234186948]]. This RMI Target has been forcibly removed to prevent a memory leak. 30-Nov-2021 13:59:36.987 SEVERE [main] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesRmiTargets Found RMI Target with stub class class [sun.rmi.registry.RegistryImpl_Stub] and value [RegistryImpl_Stub[UnicastRef [liveRef: [endpoint:[157.161.91.47:1096](local),objID:[0:0:0, 0]. This RMI Target has been forcibly removed to prevent a memory leak. Why do the three methods to shutdown Tomcat differ and how can I make 'catalina.sh stop' or the shutdown listener work the same way like sending the OS signal. I've tried, beside a lot of other things, to set skipMemoryLeakChecksOnJvmShutdown="true" in context.xml but it seems to change nothing at all. Any help would be much appreciated. Thanks, Simon - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
