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Posted to users@servicemix.apache.org by Maciej Prochniak <mp...@touk.pl> on 2009/07/27 09:14:08 UTC
shutdown->start causing error with camel DeadLetterChannel
Hello,
We found strange (I would say - buggy) behaviour of servicemix-camel
component (SMX 3.3 + servicemix-camel 2008.01).
Basically we have camel SU using standard dead letter channel. When SA
is shutdown (e.g. because of missing components for other SUs, or using
JMX) and then started, camel route throws RejectedExecutionException.
Looking into the code it is caused by the following:
1) Camel context is created during deployment of SU
2) When shutdown is being called, the applicationContext for given SU i
s destroyed. This includes calling .stop() on camelContext.
3) When start is called the camel context is still in stopped state (but
its servicemix endpoint are still registered in SMX registry).
4) Dead letter channel throws exceptions when receiving messages while
being in stopped state.
For me, this looks like some compatibility issues between camel
endpoints lifecycle and servicemix endpoints lifecycle (this is mostly
coded in AbstractXBeanDeployer and XBeanServiceUnit). The application
context is destroyed in shutdown method, but if start is called
afterwards, endpoint beans are being used - this is rather unpleasant
behaviour in my opinion - maybe camel context should be created during
start of SU?
Could anybody comment on this?
thanks and br.
maciek prochniak
Re: shutdown->start causing error with camel DeadLetterChannel
Posted by Willem Jiang <wi...@gmail.com>.
Hi Gert,
I just create a JIRA[1] with the patch (also a test case). Please review
it if your have time.
[1] https://issues.apache.org/activemq/browse/SMXCOMP-687
Thanks,
Willem
Gert Vanthienen wrote:
> Willem,
>
> The Endpoint interface has been extended to allow for a cleaner
> shutdown process for consumer endpoints, where the endpoint can
> continue handling existing requests without accepting new ones (cfr.
> http://svn.apache.org/repos/asf/servicemix/components/shared-libraries/trunk/servicemix-common/src/main/java/org/apache/servicemix/common/Endpoint.java).
>
> Perhaps we can reuse the same mechanism for fine-tuning the stop/start
> behavior of the Camel endpoints?
>
> Regards,
>
> Gert Vanthienen
> ------------------------
> Open Source SOA: http://fusesource.com
> Blog: http://gertvanthienen.blogspot.com/
>
>
>
> 2009/11/30 Willem Jiang <wi...@gmail.com>:
>> Hi,
>>
>> I had a chance to dig the code of service-camel component trunk.
>> Here is what I found :
>> For ServiceUnit there are two stages of starting
>> prepare for starting --> init()
>> start the endpoints of the unit --> start()
>>
>> And two stages of stopping
>> stop the endpoints of the unit --> stop()
>> finally stop the service unit --> shutdown()
>>
>> For service-camel component, it uses XBeanServiceUnit to manage the SU's
>> states, the camel context will be stopped if the su's shutdown is called.
>> But the camel context will not be restarted even the su's init() is called.
>>
>> As the SU start method will start the endpoint, we can create a simple
>> endpoint which delegate the start and stop method to camel context.
>>
>> Any thought?
>>
>>
>> Willem
>>
>> Jean-Baptiste Onofré wrote:
>>> Hi Maciek,
>>>
>>> I'm agree, we haven't a clean behavior between SMX component and camel
>>> endpoints. I think the best way is to override the start() method in the
>>> camel component to rebind the camel context.
>>>
>>> Feel free to open a Jira task on this topic.
>>>
>>> Regards
>>> JB
>>>
>>> Maciej Prochniak wrote:
>>>> Hello,
>>>> We found strange (I would say - buggy) behaviour of servicemix-camel
>>>> component (SMX 3.3 + servicemix-camel 2008.01).
>>>>
>>>> Basically we have camel SU using standard dead letter channel. When SA
>>>> is shutdown (e.g. because of missing components for other SUs, or using
>>>> JMX) and then started, camel route throws RejectedExecutionException.
>>>> Looking into the code it is caused by the following:
>>>>
>>>> 1) Camel context is created during deployment of SU
>>>> 2) When shutdown is being called, the applicationContext for given SU i
>>>> s destroyed. This includes calling .stop() on camelContext.
>>>> 3) When start is called the camel context is still in stopped state (but
>>>> its servicemix endpoint are still registered in SMX registry).
>>>> 4) Dead letter channel throws exceptions when receiving messages while
>>>> being in stopped state.
>>>>
>>>> For me, this looks like some compatibility issues between camel
>>>> endpoints lifecycle and servicemix endpoints lifecycle (this is mostly
>>>> coded in AbstractXBeanDeployer and XBeanServiceUnit). The application
>>>> context is destroyed in shutdown method, but if start is called
>>>> afterwards, endpoint beans are being used - this is rather unpleasant
>>>> behaviour in my opinion - maybe camel context should be created during
>>>> start of SU?
>>>>
>>>> Could anybody comment on this?
>>>>
>>>> thanks and br.
>>>> maciek prochniak
>>
>
Re: shutdown->start causing error with camel DeadLetterChannel
Posted by Gert Vanthienen <ge...@gmail.com>.
Willem,
The Endpoint interface has been extended to allow for a cleaner
shutdown process for consumer endpoints, where the endpoint can
continue handling existing requests without accepting new ones (cfr.
http://svn.apache.org/repos/asf/servicemix/components/shared-libraries/trunk/servicemix-common/src/main/java/org/apache/servicemix/common/Endpoint.java).
Perhaps we can reuse the same mechanism for fine-tuning the stop/start
behavior of the Camel endpoints?
Regards,
Gert Vanthienen
------------------------
Open Source SOA: http://fusesource.com
Blog: http://gertvanthienen.blogspot.com/
2009/11/30 Willem Jiang <wi...@gmail.com>:
> Hi,
>
> I had a chance to dig the code of service-camel component trunk.
> Here is what I found :
> For ServiceUnit there are two stages of starting
> prepare for starting --> init()
> start the endpoints of the unit --> start()
>
> And two stages of stopping
> stop the endpoints of the unit --> stop()
> finally stop the service unit --> shutdown()
>
> For service-camel component, it uses XBeanServiceUnit to manage the SU's
> states, the camel context will be stopped if the su's shutdown is called.
> But the camel context will not be restarted even the su's init() is called.
>
> As the SU start method will start the endpoint, we can create a simple
> endpoint which delegate the start and stop method to camel context.
>
> Any thought?
>
>
> Willem
>
> Jean-Baptiste Onofré wrote:
>>
>> Hi Maciek,
>>
>> I'm agree, we haven't a clean behavior between SMX component and camel
>> endpoints. I think the best way is to override the start() method in the
>> camel component to rebind the camel context.
>>
>> Feel free to open a Jira task on this topic.
>>
>> Regards
>> JB
>>
>> Maciej Prochniak wrote:
>>>
>>> Hello,
>>> We found strange (I would say - buggy) behaviour of servicemix-camel
>>> component (SMX 3.3 + servicemix-camel 2008.01).
>>>
>>> Basically we have camel SU using standard dead letter channel. When SA
>>> is shutdown (e.g. because of missing components for other SUs, or using
>>> JMX) and then started, camel route throws RejectedExecutionException.
>>> Looking into the code it is caused by the following:
>>>
>>> 1) Camel context is created during deployment of SU
>>> 2) When shutdown is being called, the applicationContext for given SU i
>>> s destroyed. This includes calling .stop() on camelContext.
>>> 3) When start is called the camel context is still in stopped state (but
>>> its servicemix endpoint are still registered in SMX registry).
>>> 4) Dead letter channel throws exceptions when receiving messages while
>>> being in stopped state.
>>>
>>> For me, this looks like some compatibility issues between camel
>>> endpoints lifecycle and servicemix endpoints lifecycle (this is mostly
>>> coded in AbstractXBeanDeployer and XBeanServiceUnit). The application
>>> context is destroyed in shutdown method, but if start is called
>>> afterwards, endpoint beans are being used - this is rather unpleasant
>>> behaviour in my opinion - maybe camel context should be created during
>>> start of SU?
>>>
>>> Could anybody comment on this?
>>>
>>> thanks and br.
>>> maciek prochniak
>>
>
>
Re: shutdown->start causing error with camel DeadLetterChannel
Posted by Willem Jiang <wi...@gmail.com>.
Hi,
I had a chance to dig the code of service-camel component trunk.
Here is what I found :
For ServiceUnit there are two stages of starting
prepare for starting --> init()
start the endpoints of the unit --> start()
And two stages of stopping
stop the endpoints of the unit --> stop()
finally stop the service unit --> shutdown()
For service-camel component, it uses XBeanServiceUnit to manage the SU's
states, the camel context will be stopped if the su's shutdown is
called. But the camel context will not be restarted even the su's init()
is called.
As the SU start method will start the endpoint, we can create a simple
endpoint which delegate the start and stop method to camel context.
Any thought?
Willem
Jean-Baptiste Onofré wrote:
> Hi Maciek,
>
> I'm agree, we haven't a clean behavior between SMX component and camel
> endpoints. I think the best way is to override the start() method in the
> camel component to rebind the camel context.
>
> Feel free to open a Jira task on this topic.
>
> Regards
> JB
>
> Maciej Prochniak wrote:
>> Hello,
>> We found strange (I would say - buggy) behaviour of servicemix-camel
>> component (SMX 3.3 + servicemix-camel 2008.01).
>>
>> Basically we have camel SU using standard dead letter channel. When SA
>> is shutdown (e.g. because of missing components for other SUs, or using
>> JMX) and then started, camel route throws RejectedExecutionException.
>> Looking into the code it is caused by the following:
>>
>> 1) Camel context is created during deployment of SU
>> 2) When shutdown is being called, the applicationContext for given SU i
>> s destroyed. This includes calling .stop() on camelContext.
>> 3) When start is called the camel context is still in stopped state (but
>> its servicemix endpoint are still registered in SMX registry).
>> 4) Dead letter channel throws exceptions when receiving messages while
>> being in stopped state.
>>
>> For me, this looks like some compatibility issues between camel
>> endpoints lifecycle and servicemix endpoints lifecycle (this is mostly
>> coded in AbstractXBeanDeployer and XBeanServiceUnit). The application
>> context is destroyed in shutdown method, but if start is called
>> afterwards, endpoint beans are being used - this is rather unpleasant
>> behaviour in my opinion - maybe camel context should be created during
>> start of SU?
>>
>> Could anybody comment on this?
>>
>> thanks and br.
>> maciek prochniak
>
Re: shutdown->start causing error with camel DeadLetterChannel
Posted by Jean-Baptiste Onofré <jb...@nanthrax.net>.
Hi Maciek,
I'm agree, we haven't a clean behavior between SMX component and camel
endpoints. I think the best way is to override the start() method in the
camel component to rebind the camel context.
Feel free to open a Jira task on this topic.
Regards
JB
Maciej Prochniak wrote:
> Hello,
> We found strange (I would say - buggy) behaviour of servicemix-camel
> component (SMX 3.3 + servicemix-camel 2008.01).
>
> Basically we have camel SU using standard dead letter channel. When SA
> is shutdown (e.g. because of missing components for other SUs, or using
> JMX) and then started, camel route throws RejectedExecutionException.
> Looking into the code it is caused by the following:
>
> 1) Camel context is created during deployment of SU
> 2) When shutdown is being called, the applicationContext for given SU i
> s destroyed. This includes calling .stop() on camelContext.
> 3) When start is called the camel context is still in stopped state (but
> its servicemix endpoint are still registered in SMX registry).
> 4) Dead letter channel throws exceptions when receiving messages while
> being in stopped state.
>
> For me, this looks like some compatibility issues between camel
> endpoints lifecycle and servicemix endpoints lifecycle (this is mostly
> coded in AbstractXBeanDeployer and XBeanServiceUnit). The application
> context is destroyed in shutdown method, but if start is called
> afterwards, endpoint beans are being used - this is rather unpleasant
> behaviour in my opinion - maybe camel context should be created during
> start of SU?
>
>
> Could anybody comment on this?
>
> thanks and br.
> maciek prochniak
>