Databases Reference
In-Depth Information
Retry action
The
Retry
action instructs the fault management framework to retry a failed service
invocation until it is successful or it reaches a specified limit. In the previous
example, we have specified that we will retry the service five times, and if the
invocation still fails after this, we have specified that we want to invoke the
ora-human-intervention
action.
The
Retry
action takes a number of parameters that allow us to configure how it
behaves, and they are defined as follows:
retryCount
- This specifies the maximum number of retries before this
action completes with a failure status.
retryInterval
- This specifies the period in seconds between retries.
exponentialBackoff
- This is an optional element, which takes no
parameters. When specified, if a retry fails, the interval between this retry
and the next retry is twice that of the previous interval. In the previous
example, the first retry would occur after 15 seconds, the second after 30
seconds, the third after 60 seconds, and so on.
retrySuccessAction
- This is an optional element with a single attribute
ref. This references another action to be taken upon successful retry of a
service. This should only be used to reference a java action (see below),
which we can use to generate an alert.
retryFailureAction
- This is an optional element with a single attribute ref
that allows you to define the action to be carried out, should all retries fail.
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For scenarios where the interaction between a BPEL process and its client are
synchronous, we should only use small retry periods. This is because we are
suspending the BPEL process between retries; thus if the retry period is too long, the
client which invoked the BPEL process could timeout while waiting for a response.
Human intervention action
For errors which are more permanent, the
humanIntervention
action gives us the
ability to suspend the routing rule or process where the fault is occurring. Once
suspended, we can log into the Fusion Middleware Control Console in Enterprise
Manager to manually handle the fault.
