Oracle SOA/BPM/OSB Blog: Error Handling

Introduction

In this blog we see error handling in BPM using Fault Management Framework.

Oracle SOA Suite provides a generic fault management framework for handling faults. If a fault occurs during runtime, the framework catches the fault and performs a user-specified action defined in a fault policy file

Similarly, We can design and execute fault policies for Oracle BPM Suite. The fault policies file defines fault conditions and their corresponding fault recovery actions. The fault policy bindings file associates the policies defined in the fault policies file with one of the following:

Composite with a BPMN process
Oracle BPMN process service component
Reference binding component (for example, another BPMN process or a JCA adapter)

The following fault recovery actions are supported in the fault policies file for Oracle BPM Suite:

Retry
Human intervention
Terminate
Java code

Here we will cover composite, componet and referenc binding level fault policies.

1. Composite Level Fault Policies

In this demo we will try to insert new employee records into database and check how error framework behaves when exception raised by bpm process.

Employee Business Object

FaultThrower bpm process

Input request mapping

Service mapping

ErrorHandlerProcess bpm process

Create fault-policies.xml file in root folder of project.

<?xml version="1.0" encoding="UTF-8"?>
<faultPolicies xmlns="http://schemas.oracle.com/bpel/faultpolicy"
               xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <faultPolicy version="0.0.1" id="comp_faultPolicy"
                 xmlns:env="http://schemas.xmlsoap.org/soap/envelope/"
                 xmlns:xs="http://www.w3.org/2001/XMLSchema"
                 xmlns="http://schemas.oracle.com/bpel/faultpolicy"
                 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <Conditions>
            
            <faultName>
                <condition>
                   <action ref="Action-Retry"/>
                </condition>
            </faultName>
        </Conditions>
        <Actions>
            <Action id="Action-Abort">
                <abort/>
            </Action>
            <Action id="Action-Retry">
                  <retry>
                    <retryCount>3</retryCount>
                    <retryInterval>10</retryInterval>
                    <exponentialBackoff/>
                    <retryFailureAction ref="Action-human-intervention"/>
                </retry>
            </Action>
            <Action id="Action-human-intervention">
                <humanIntervention/>
            </Action>
        </Actions>
     </faultPolicy>
</faultPolicies>

As mentioned in the fault policy file, if any error occurs, error framework will try three times in 10 second interval.

Create fault_binding.xml in root folder of project.

<?xml version="1.0" encoding="UTF-8"?>
<faultPolicyBindings version="2.0.1" xmlns="http://schemas.oracle.com/bpel/faultpolicy">

    <composite faultPolicy="comp_faultPolicy"/>
</faultPolicyBindings>

Configure these files in composite.xml file

I tried to insert dupilcate record in database whcich causes db adapter to throw binding fault in FaultThrower bpm proces. As per fault policy error framework retried to insert same record 3 times and then end the bpm process.

2. Service Component Level Fault Policies

Similarly we can define fault policies for service component

fault-policies.xml

<?xml version="1.0" encoding="UTF-8"?>
<faultPolicies xmlns="http://schemas.oracle.com/bpel/faultpolicy"
               xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <faultPolicy version="0.0.1" id="ComponentPolicy"
                 xmlns:env="http://schemas.xmlsoap.org/soap/envelope/"
                 xmlns:xs="http://www.w3.org/2001/XMLSchema"
                 xmlns="http://schemas.oracle.com/bpel/faultpolicy"
                 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<Conditions>
        
        <faultName>
            <condition>
               <action ref="Action-human-intervention"/>
            </condition>
        </faultName>
    </Conditions>
    <Actions>
        <Action id="Action-Abort">
            <abort/>
        </Action>
        <Action id="Action-Retry">
              <retry>
                <retryCount>3</retryCount>
                <retryInterval>2</retryInterval>
                <exponentialBackoff/>
            </retry>
        </Action>
        <Action id="Action-human-intervention">
            <humanIntervention/>
        </Action>
    </Actions>
</faultPolicy>
</faultPolicies>

fualt-bindings.xml

<?xml version="1.0" encoding="UTF-8"?>
<faultPolicyBindings version="2.0.1" xmlns="http://schemas.oracle.com/bpel/faultpolicy">
    <component faultPolicy="ComponentPolicy">
        <name>TestProcess</name>
    </component>
</faultPolicyBindings>

3. Reference Level Fault Policies

Same way we can define fault policies for reference services

fault-policies.xml

<?xml version="1.0" encoding="UTF-8"?>
<faultPolicies xmlns="http://schemas.oracle.com/bpel/faultpolicy"
               xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <faultPolicy version="0.0.1" id="Policy0"
                 xmlns:env="http://schemas.xmlsoap.org/soap/envelope/"
                 xmlns:xs="http://www.w3.org/2001/XMLSchema"
                 xmlns="http://schemas.oracle.com/bpel/faultpolicy"
                 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <Conditions>
            
            <faultName>
                <condition>
                  <action ref="Action-human-intervention"/>
                </condition>
            </faultName>
        </Conditions>
        <Actions>
            <Action id="Action-human-intervention">
                <humanIntervention/>
            </Action>
        </Actions>
     </faultPolicy>
</faultPolicies>

fault.bindings.xml

<?xml version="1.0" encoding="UTF-8"?>
<faultPolicyBindings version="2.0.1" xmlns="http://schemas.oracle.com/bpel/faultpolicy">

    <reference faultPolicy="Policy0">
        <name>Services.Externals.WriteFile_Orderdata.reference</name>
    </reference>
</faultPolicyBindings>

When a process is called using a service reference, the reference used is not the BPMN process reference, but rather the reference created to call the BPMN process named Services.Externals.TestProcess2Service.reference.

fault-policies.xml

<?xml version="1.0" encoding="UTF-8"?>
<faultPolicies xmlns="http://schemas.oracle.com/bpel/faultpolicy"
               xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <faultPolicy version="0.0.1" id="Policy1"
                 xmlns:env="http://schemas.xmlsoap.org/soap/envelope/"
                 xmlns:xs="http://www.w3.org/2001/XMLSchema"
                 xmlns="http://schemas.oracle.com/bpel/faultpolicy"
                 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <Conditions>
            
            <faultName>
                <condition>
                  <action ref="Action-human-intervention"/>
                </condition>
            </faultName>
        </Conditions>
        <Actions>
            <Action id="Action-human-intervention">
                <humanIntervention/>
            </Action>
        </Actions>
     </faultPolicy>
</faultPolicies>

fault.bindings.xml

<?xml version="1.0" encoding="UTF-8"?>
<faultPolicyBindings version="2.0.1" xmlns="http://schemas.oracle.com/bpel/faultpolicy">

    
    <reference faultPolicy="Policy1">
        <name>Services.Externals.TestProcess2Service.reference</name>
    </reference>
</faultPolicyBindings>

Reference service name can be obtained from composite.xml from the wire section

In next blog we will see how to handle System Exception.

Oracle SOA/BPM/OSB Blog

Thursday, March 5, 2015

Error Handling in BPM 11G/12C - Fault Management Framework - Part 2

Introduction

1. Composite Level Fault Policies

2. Service Component Level Fault Policies

3. Reference Level Fault Policies