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Posted to users@camel.apache.org by Mark Kusec <mk...@mdacorporation.com> on 2015/02/05 20:16:11 UTC
Retry strategy with loadRoutesDefinition
Hi all,
I have refactored a legacy Java application (i.e. no web container) to use Camel to send messages from files to a queue. I chose to describe my routes in XML so the routes could be re-used in a future Spring web application. My legacy application loads the XML routes using ModelCamelContext.loadRoutesDefinition().
Because I don't have Spring, I'm limited in what I can describe in my XML file. Although the documentation isn't too specific, I believe that the XML file can only contain routes. For example, I can't declare beans in the XML file, so I declare them in a SimpleRegistry and provide that to the CamelContext before I load the routes definition file.
I am having trouble finding a way to give Camel a retry strategy for when there are connectivity issues with the broker. How would I give Camel instructions on how many times to retry, backoff multipliers, etc?
Since my XML file only contains routes, it doesn't seem like I can use <onException> or <errorHandler>. Is there some alternate way to declare either of these, without switching to the Java DSL?
(Also, according to http://camel.465427.n5.nabble.com/global-onException-doesnt-apply-for-routes-loaded-with-loadRoutesDefinition-td4288369.html#a4290365, it appears that routes loaded via loadRoutesDefinition don't get the benefit of onException anyway, at least not until Camel 3.)
If I'm on the wrong track, is there some other way that I can tell Camel to retry periodically (forever) when it is unable to send to a queue?
Thanks,
Mark
Re: Retry strategy with loadRoutesDefinition
Posted by Claus Ibsen <cl...@gmail.com>.
Hi
Yeah for error handler you only refer to an existing error handler
using errorHandlerRef. But <onException> can do all the same as an
<errorHandler> does also.
On Sat, Feb 7, 2015 at 12:35 AM, Mark Kusec <mk...@mdacorporation.com> wrote:
> Thanks Claus, I was able to get onException working by putting it inside the route in my route definition file.
>
> <routes xmlns="http://camel.apache.org/schema/spring">
> <route id="foo">
> <onException>
> ...
>
> I could not figure a way to define an error handler or redeliveryPolicyProfile in a route definition file (as with bean definitions, it doesn't seem that Camel wants to read these kinds of definitions from a route definition file).
>
> In order to specify an error handler, I had to add it to the SimpleRegistry manually before loading the routes, i.e.:
>
> DeadLetterChannelBuilder errorHandler = new DeadLetterChannelBuilder();
> errorHandler.getRedeliveryPolicy().setMaximumRedeliveries(3);
> errorHandler.getRedeliveryPolicy().setRedeliveryDelay(5000);
> errorHandler.setDeadLetterUri(deadLetterDestination);
> registry.put("deadLetterHandler", errorHandler );
>
> Then I could refer to it in the route definition file:
>
> <routes xmlns="http://camel.apache.org/schema/spring">
> <route id="foo" errorHandlerRef="deadLetterHandler">
> ...
>
> But in the end, I found that I could get my desired retry behavior using onException alone, so I abandoned the approach of registering an error handler programmatically.
>
> Is there a better way to use an error handler in conjunction with a route definition file, other than the SimpleRegistry approach that I showed above?
>
> Thanks
> Mark
>
>
> -----Original Message-----
> From: Claus Ibsen [mailto:claus.ibsen@gmail.com]
> Sent: Friday, February 06, 2015 12:14 AM
> To: users@camel.apache.org
> Subject: Re: Retry strategy with loadRoutesDefinition
>
> Hi
>
> You can inline error handler and onException in your XML routes.
>
> On Thu, Feb 5, 2015 at 8:16 PM, Mark Kusec <mk...@mdacorporation.com> wrote:
>> Hi all,
>>
>> I have refactored a legacy Java application (i.e. no web container) to use Camel to send messages from files to a queue. I chose to describe my routes in XML so the routes could be re-used in a future Spring web application. My legacy application loads the XML routes using ModelCamelContext.loadRoutesDefinition().
>>
>> Because I don't have Spring, I'm limited in what I can describe in my XML file. Although the documentation isn't too specific, I believe that the XML file can only contain routes. For example, I can't declare beans in the XML file, so I declare them in a SimpleRegistry and provide that to the CamelContext before I load the routes definition file.
>>
>> I am having trouble finding a way to give Camel a retry strategy for when there are connectivity issues with the broker. How would I give Camel instructions on how many times to retry, backoff multipliers, etc?
>>
>> Since my XML file only contains routes, it doesn't seem like I can use <onException> or <errorHandler>. Is there some alternate way to declare either of these, without switching to the Java DSL?
>>
>> (Also, according to http://camel.465427.n5.nabble.com/global-onException-doesnt-apply-for-routes-loaded-with-loadRoutesDefinition-td4288369.html#a4290365, it appears that routes loaded via loadRoutesDefinition don't get the benefit of onException anyway, at least not until Camel 3.)
>>
>> If I'm on the wrong track, is there some other way that I can tell Camel to retry periodically (forever) when it is unable to send to a queue?
>>
>> Thanks,
>> Mark
>>
>
>
>
> --
> Claus Ibsen
> -----------------
> Red Hat, Inc.
> Email: cibsen@redhat.com
> Twitter: davsclaus
> Blog: http://davsclaus.com
> Author of Camel in Action: http://www.manning.com/ibsen
> hawtio: http://hawt.io/
> fabric8: http://fabric8.io/
>
--
Claus Ibsen
-----------------
Red Hat, Inc.
Email: cibsen@redhat.com
Twitter: davsclaus
Blog: http://davsclaus.com
Author of Camel in Action: http://www.manning.com/ibsen
hawtio: http://hawt.io/
fabric8: http://fabric8.io/
RE: Retry strategy with loadRoutesDefinition
Posted by Mark Kusec <mk...@mdacorporation.com>.
Thanks Claus, I was able to get onException working by putting it inside the route in my route definition file.
<routes xmlns="http://camel.apache.org/schema/spring">
<route id="foo">
<onException>
...
I could not figure a way to define an error handler or redeliveryPolicyProfile in a route definition file (as with bean definitions, it doesn't seem that Camel wants to read these kinds of definitions from a route definition file).
In order to specify an error handler, I had to add it to the SimpleRegistry manually before loading the routes, i.e.:
DeadLetterChannelBuilder errorHandler = new DeadLetterChannelBuilder();
errorHandler.getRedeliveryPolicy().setMaximumRedeliveries(3);
errorHandler.getRedeliveryPolicy().setRedeliveryDelay(5000);
errorHandler.setDeadLetterUri(deadLetterDestination);
registry.put("deadLetterHandler", errorHandler );
Then I could refer to it in the route definition file:
<routes xmlns="http://camel.apache.org/schema/spring">
<route id="foo" errorHandlerRef="deadLetterHandler">
...
But in the end, I found that I could get my desired retry behavior using onException alone, so I abandoned the approach of registering an error handler programmatically.
Is there a better way to use an error handler in conjunction with a route definition file, other than the SimpleRegistry approach that I showed above?
Thanks
Mark
-----Original Message-----
From: Claus Ibsen [mailto:claus.ibsen@gmail.com]
Sent: Friday, February 06, 2015 12:14 AM
To: users@camel.apache.org
Subject: Re: Retry strategy with loadRoutesDefinition
Hi
You can inline error handler and onException in your XML routes.
On Thu, Feb 5, 2015 at 8:16 PM, Mark Kusec <mk...@mdacorporation.com> wrote:
> Hi all,
>
> I have refactored a legacy Java application (i.e. no web container) to use Camel to send messages from files to a queue. I chose to describe my routes in XML so the routes could be re-used in a future Spring web application. My legacy application loads the XML routes using ModelCamelContext.loadRoutesDefinition().
>
> Because I don't have Spring, I'm limited in what I can describe in my XML file. Although the documentation isn't too specific, I believe that the XML file can only contain routes. For example, I can't declare beans in the XML file, so I declare them in a SimpleRegistry and provide that to the CamelContext before I load the routes definition file.
>
> I am having trouble finding a way to give Camel a retry strategy for when there are connectivity issues with the broker. How would I give Camel instructions on how many times to retry, backoff multipliers, etc?
>
> Since my XML file only contains routes, it doesn't seem like I can use <onException> or <errorHandler>. Is there some alternate way to declare either of these, without switching to the Java DSL?
>
> (Also, according to http://camel.465427.n5.nabble.com/global-onException-doesnt-apply-for-routes-loaded-with-loadRoutesDefinition-td4288369.html#a4290365, it appears that routes loaded via loadRoutesDefinition don't get the benefit of onException anyway, at least not until Camel 3.)
>
> If I'm on the wrong track, is there some other way that I can tell Camel to retry periodically (forever) when it is unable to send to a queue?
>
> Thanks,
> Mark
>
--
Claus Ibsen
-----------------
Red Hat, Inc.
Email: cibsen@redhat.com
Twitter: davsclaus
Blog: http://davsclaus.com
Author of Camel in Action: http://www.manning.com/ibsen
hawtio: http://hawt.io/
fabric8: http://fabric8.io/
Re: Retry strategy with loadRoutesDefinition
Posted by Claus Ibsen <cl...@gmail.com>.
Hi
You can inline error handler and onException in your XML routes.
On Thu, Feb 5, 2015 at 8:16 PM, Mark Kusec <mk...@mdacorporation.com> wrote:
> Hi all,
>
> I have refactored a legacy Java application (i.e. no web container) to use Camel to send messages from files to a queue. I chose to describe my routes in XML so the routes could be re-used in a future Spring web application. My legacy application loads the XML routes using ModelCamelContext.loadRoutesDefinition().
>
> Because I don't have Spring, I'm limited in what I can describe in my XML file. Although the documentation isn't too specific, I believe that the XML file can only contain routes. For example, I can't declare beans in the XML file, so I declare them in a SimpleRegistry and provide that to the CamelContext before I load the routes definition file.
>
> I am having trouble finding a way to give Camel a retry strategy for when there are connectivity issues with the broker. How would I give Camel instructions on how many times to retry, backoff multipliers, etc?
>
> Since my XML file only contains routes, it doesn't seem like I can use <onException> or <errorHandler>. Is there some alternate way to declare either of these, without switching to the Java DSL?
>
> (Also, according to http://camel.465427.n5.nabble.com/global-onException-doesnt-apply-for-routes-loaded-with-loadRoutesDefinition-td4288369.html#a4290365, it appears that routes loaded via loadRoutesDefinition don't get the benefit of onException anyway, at least not until Camel 3.)
>
> If I'm on the wrong track, is there some other way that I can tell Camel to retry periodically (forever) when it is unable to send to a queue?
>
> Thanks,
> Mark
>
--
Claus Ibsen
-----------------
Red Hat, Inc.
Email: cibsen@redhat.com
Twitter: davsclaus
Blog: http://davsclaus.com
Author of Camel in Action: http://www.manning.com/ibsen
hawtio: http://hawt.io/
fabric8: http://fabric8.io/