Fuse IDE - Enterprise Integration Pattern Reference

Name

On Exception — Route to be executed when an exception is thrown

Usage

The on exception pattern defines a set of steps that are executed when an exception is thrown. It can either be scoped local to a specific route or globally for all routes defined in the context.

	Important
	Locally scoped on exception patterns take precedent over globally scoped ones. Therefore in a locally scoped on exception pattern exists, the globally scoped pattern will not be executed.

When specifying a locally scoped on exception pattern, the pattern directly follows the from endpoint in the route.

When specifying a globally scoped on exception pattern, the pattern starts a new route.

Properties

Table 4.9 describes the properties you can specify using the properties editor.

Table 4.9. On Exception Properties

Name	Description
Continued	Specifies an expression that determines if the exception is ignored and the original route continues processing after the `onException` route completes.^[a]
language	Specifies the expression language used to process the expression.
Retry While	Specifies an expression that determines if the message causing the exception should be redelivered. The message is redelivered until the expression evaluates to `false`.^[a]
language	Specifies the expression language used to process the expression.
Handled	Specifies an expression that determines if the exception is marked as handled.^[a]
language	Specifies the expression language used to process the expression.
Exceptions	Specifies the list of exceptions the node handles. The Add button adds an entry typed in the field. The Delete button removes the selected entry from the list.
Redelivery Policy Ref	Specifies a reference to bean defining the redelivery policy.
On Redelivery Ref	Specifies a reference to a custom processor for processing the message before it is redelivered.
Inherit Error Handler	Specifies if the node should use the error handler configured for the route.
Use Original Message Policy	Specifies that message that began the route is placed in the dead letter queue instead of the message that caused the exception.
Id	Specifies a unique identifier for the endpoint. The Id can be used to refer to the endpoint in the Apache Camel configuration file.
Description	Specifies a text description of the bean. The description is included in the generated XML file.
^[a]The expression is treated as returning a boolean. If the expression evaluates to any non-boolean value other than `null` it is evaluated as returning `true`.

Redelivery Policy

Table 4.10 describes the properties for configuring the redelivery policy.

Table 4.10. Redelivery Properties

Name	Description
Async Delayed Redelivery
Back Off Multiplier	Specifies the multiplier used to determine the redelivery delay if exponential back-off is enabled. If `m` is the back-off multiplier and `d` is the redelivery delay, the sequence of redelivery attempts are then timed as follows: d, md, mmd, mmmd, ...
Collision Avoidance Factor	Specifies a factor that is used to randomly tweak the redelivery delay if collision avoidance is enabled. The collision avoidance policy tweaks the next delay by a random amount, up to plus/minus `p`% of its current value.
Delay Pattern
Disable Redelivery	Specifies if the redelivery feature is disabled. Redelivery is enabled if Maximum Redeliveries is set to a positive number.
Log Continued
Log Exhausted
Log Handled
Log Retry Attempted
Log Retry Stack Trace
Log Stack Trace	Specifies if the JVM stack trace is included in the error logs.
Maximum Redeliveries	Specifies the maximum number of delivery attempts
Maximum Redelivery Delay	Specifies, in milliseconds, the maximum redelivery delay when using an exponential back-off strategy.
Redelivery Delay	Specifies the delay (in milliseconds) between redelivery attempts.
Retries Exhausted Log Level	Specifies the logging level at which to log delivery failure.
Retry Attempted Log Level	Specifies the logging level at which to redelivery attempts.
Use Collision Avoidance	Enables collision avoidance, which adds some randomization to the back-off timings to reduce contention probability.
Use Exponential Back Off	Enables exponential backoff.

Name

Usage

Properties

Redelivery Policy

Related topics