Luc Gorissen Solution Architect - AMIS - The Netherlands

Transcription

1 FAULT HANDLING IN ACM/BPM IMPLEMENTATIONS OGH Luc Gorissen Solution Architect - AMIS - The Netherlands

2 CONTEXT CASE MGT IMPLEMENTATION: 1.5 X 10 6 CASES / YR Product ADF: Application Development Framework ACM: Adaptive Case Management BPM: Business Process Management SOA: Service Oriented Architecture OSB: Oracle Service Bus WCC: WebCenter Content Purpose Enterprise UI application Case Control Business Process execution Services implementation, orchestration Service Bus Document Storage

3 FAULT HANDLING IN ACM/BPM IMPLEMENTATIONS WHAT IF YOU DON T THINK THEORY FAULT CATEGORIES FAULT STRATEGY GUIDELINES IMPLEMENTATION SUMMARY

4 WHAT IF YOU DON T THINK? or get enough time to do it properly Fault Handling == use Fault Policies - Limited in scope: - Limited to 1 activity - Limited to invokes Programming style

5 WHAT IF YOU DON T THINK? ~30 minutes Consoles: not workable Log files: not workable No purging Sys/Appl Mgt just don t know

6 WHAT IF YOU DON T THINK? Application management: - Splunk with log levels on debug - Abundant use of retries in Fault Handling Dangerous combination with: - slow disk i/o - abundant synchronous calls - high load Have you been here also?

7 THEORY Ingredients: Fault Categories Fault Strategy Layering Model Design Guidelines + Implementation Guidelines Fault Handling Implementation

8 FAULT CATEGORIES Fault Category Description Example Functional Technical Mostly data related Predictable Technical cause Unpredictable Timeout Insufficient progress Person not found Account balance insufficient Network not available Out of memory No response from service Task stays open for too long Interrupt Interference in normal flow Abort execution of a process What you handle

9 FAULT STRATEGY Detection: where and when are what functional faults detected? Signaling: to whom are timeouts signaled? Signaling: what will the (end) user see in case of a fault? Recovery: who handles what fault? Recovery: block case execution until fault is recovered? Recovery: where is what fault handled? Fault Strategy: detect, signal, recover

10 FAULT STRATEGY - EXAMPLES Front-end faults: end user receives unique error message: contact Customer Support Centre Back-end faults: Primary handling by Central Application Management; If customer contact is required, that will be done by Local Administration Employees Case execution is never blocked Timeout monitoring by Splunk dashboards on log files

11 Detect, Signal, Recover: - Adding structure LAYERING MODEL Presentation Layer PRES1 PRES2 Case Layer Case Control Case Activity Case Task Services Layer Complex Simple Application Layer DMS Data Layer DB

12 LAYERING MODEL PATTERN EXAMPLE Presentation Layer PRES1 Simple read data pattern - Person not found Case Layer Services Layer Application Layer Simple Data Layer DB

13 LAYERING MODEL PATTERN EXAMPLE Presentation Layer Data write from case activity Case Layer Case Control Case Activity Case Task Services Layer Complex Simple Simple Simple Application Layer DMS Data Layer DB

14 WHERE ARE WE? Ingredients Fault Categories Fault Strategy Layering Model Design Guidelines + Implementation Guidelines Fault Handling Implementation

15 DESIGN GUIDELINES UI designers Process designers Behavior around Faults A-synchronous back-end faults Process steps Service designers Atomic, idempotent Combining Fault Categories Fault Strategy Layering model

16 DESIGN GUIDELINES UI DESIGNER Value checks in UI / presentation layer? (detect: functional fault) From DropDown List to Input Field on error (recover: technical fault) Status indicator for a case (signaling) Formatting and information on error messages (signaling / recover)

17 DESIGN GUIDELINES PROCESS DESIGNER Normal: Process steps, taking into account: Functionality, Time, Participants Re-usability Now also: How to handle faults in atomic process step (detect, signal, recover) Increase automated handling of faults (detect, signal, recover) This is NOT an exact science

18 IMPLEMENTATION GUIDELINES How to implement Fault Handling technically: Fault Categories Fault Strategy Layering Model Design Guidelines + Implementation Guidelines Fault Handling Implementation

19 IMPLEMENTATION GUIDELINES - EXAMPLES 1. Read pattern: the person that doesn t exist 2. BPM Write pattern: with external fault handling

20 IMPLEMENTATION GUIDELINES READ PATTERN Presentation Layer ADF PRES1 Simple read data pattern - Looking for a person that doesn t exist Case Layer Services Layer Application Layer Data Layer Simple DB

21 IMPLEMENTATION GUIDELINES READ PATTERN Business Fault? Where? Technical: SOAP fault??!?! Timeout & Interrupt fault N/A Sys Mgt: where to log the error? Presentation Layer Case Layer Services Layer Application Layer ADF OSB OSB Data Layer DB

22 IMPLEMENTATION GUIDELINES BPM WRITE PATTERN Presentation Layer Case Layer Case Activity Services Layer Read1 Read2 Write Application Layer DMS Data Layer DB

23 IMPLEMENTATION GUIDELINES BPM WRITE PATTERN Presentation Layer Case Layer BPM A-synchronous for orchestration Services Layer Application Layer JAX-WS Data Layer DB

24 IMPLEMENTATION GUIDELINES BPM WRITE PATTERN Traditional approach in BPM process Boundary catch of exception Clutters up the process flow Event sub process for exception Ends the process Exception Catch + 12c action feature (BACK, SKIP, OK) Force commit after execution (12c) Limited in scope to 1 flow object A great help.

25 IMPLEMENTATION GUIDELINES BPM WRITE PATTERN Let s try to achieve: Separate fault handling organization from end user organization Re-use generic fault handling code Programmable fault handling De-couple fault handling functionality from process functionality

26 IMPLEMENTATION GUIDELINES BPM WRITE PATTERN Case Layer BPM AsyncServiceInvoker Fault Handler Fault Rules Services Layer

27 A-synchronous service invoke IMPLEMENTATION GUIDELINES BPM WRITE PATTERN BPM 1 AsyncServiceInvoker 2

28 Service fault IMPLEMENTATION GUIDELINES BPM WRITE PATTERN BPM Fault AsyncServiceInvoker Handler 2 3 Fault Rules 5 Retry, abort, continue

29 IMPLEMENTATION GUIDELINES BPM WRITE PATTERN BPM AsyncServiceInvoker Fault Handler Fault Rules

30 IMPLEMENTATION GUIDELINES BPM WRITE PATTERN

31 IMPLEMENTATION GUIDELINES BPM WRITE PATTERN BPM AsyncServiceInvoker Fault Handler Fault Rules

32 IMPLEMENTATION GUIDELINES BPM WRITE PATTERN Promised 1. Separate fault handling organization from end user organization 2. Re-use generic fault handling code 3. Programmable fault handling 4. De-couple fault handling functionality from process functionality

33 IMPLEMENTATION GUIDELINES BPM WRITE PATTERN

34 IMPLEMENTATION GUIDELINES BPM WRITE PATTERN 1. Separate fault handling organization from end user organization delivered 2. Re-use generic fault handling code 3. Programmable fault handling 4. De-couple fault handling functionality from process functionality

35 ACM Case Control is here mainly about making Case Activities available to end users, who can then start them Compare against the fault categories: Functional: n/a Technical: Oracle Timeout: case activity level Interrupt: API

36 WRAP-UP Fault Categories Fault Strategy Layering Model Design Guidelines + Implementation Guidelines Fault Handling Implementation + examples Free tip on PoC s

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