ABAP Backend Implementation of Asynchronous Services

Service enabling of SAP Business Suite - ImplementationZDSESA

ABAP backend implementation of asynchronous services

Communication Layer

Proxy Framework

XML Payload

ABAP Payload

Application Service-Enabling Layer

Restartable Service Implementation

ABAP Payload

Application Layer

BAPIAPIMethod

FEH Layer

Appl. Message Persistency

RError & Conflict Handler

Resolution Stratetgy

Determination

Post Processing

Office

SXMB_MONI Runtime

MonitoringUser Interface

ABAP Parameters

XML Message Persistency

R

Proxy Implementation

WS Runtime Local XI Runtime

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1. Integration Repository1.1. ….

2. Proxy Generation

3. Proxy implementation of Inbound Services3.1. Basic Aspects of Enterprise Service Implementation

3.1.1 Transformation, Data Mapping, Conversion3.1.2 Extensibility – BAdI Concept3.1.3 Error and Exception Handling3.1.4 Synchronous Communication

3.1.5 Asynchronous Communication3.2. Data Changing Enterprise Services3.3. ….

Agenda

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Objectives

You understand the basic programming model of asynchronous services and the impact of uni- and bi-directional communication on the backend implementation.

You understand, how to implement DB updates for asynchronous services.

You aware of the difference between errors and exceptions and you understand the Forward Error Handling (FEH) solution for asynchronous services.

You are aware of the tools available to test asynchronous services in a single service test.

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Sequence: Asynchronous Communication Option 1

Mediation via Integration Server required – but do not presuppose so! Business logic is performed inside inbound proxy (i.e. a direct BAPI call) Outbound proxy is called from inbound proxy implementation

uni-directional

bi-directional

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Sequence: Asynchronous Communication Option 2

Mediation via Integration Server required – but do not presuppose so! Business logic is at least in part ‘forwarded’ to application (asynchronous) Outbound proxy is called in separate LUW by application

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Move out of proxy into separate service implementation class

Asynchronous services – Basic Programming Model (single service)

METHOD execute_asynchronous RAISING CX_<StandardMessageFault>.

“ Switch of Extended XML Handling if switched on in CONSTRUCTOR

SET UPDATE TASK LOCAL.

CALL METHOD import_conversion … CALL BADI inbound_processing …

CALL FUNCTION … “business logic using BAPI, API, method …

“ if an error occurred in the inbound mapping or the business logicCall method <FEH register> “Register FEHCall method … “FEH processingCL_PROXY_FAULT=>RAISE …

“ if response is sent immediately (outbound service call) CALL METHOD export_conversion … *) CALL BADI outbound_processing …

“ Can you implement logical receiver determination? “ CALL function outbound proxy (in UPDATE TASK )

create object lo_proxy…..lo_proxy-> execute_asynchronous ( output ).

ENDMETHOD.

Atomic transaction; database updates local,COMMIT by framework

Conversion service-appropriate ABAP internal language

Handover erroneousdata to FEH

*) maybe to be included in the call function …. In update task

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Asynchronous Services – Database Updates

Database Updates Never invoke COMMIT WORK or ROLLBACK WORK nor any encapsulation (such as BAPI_TRANSACTION_COMMIT) NW will react with an runtime error in future!

The XI / WS-RM runtime is responsible to COMMIT or ROLLBACK (CL_PROXY_FAULT=>RAISE(error_messages) ) database updates: this is related to the Processing Status in the XI monitoring (TX SXMB_MONI)

COMMIT: message successfully completed ROLLBACK: Application errors occurred!

SET UPDATE TASK LOCAL Always use this statement at the start of a proxy implementation for data changing services Confirmation message and data changes must share the same LUW Confirmation

consistent with system state Confirmation message should be sent in the update task

CheckMan

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Asynchronous Services – Exceptions vs. Errors

Errors (FEH: Forward Error Handling)

Error and conflict situations classified at design time

Rule-based resolution strategy: Automatically by retry manually by business expert?

Returned to consumer only if request really can’t be fulfilled – as Log element in response

Errors (FEH: Forward Error Handling)

Error and conflict situations classified at design time

Rule-based resolution strategy: Automatically by retry manually by business expert?

Returned to consumer only if request really can’t be fulfilled – as Log element in response

Exceptions Fault Messages – but not

returned to consumer

Logged & monitored technical expert triggers resolution

Use RAISE operation of class CL_PROXY_FAULT

Exceptions Fault Messages – but not

returned to consumer

Logged & monitored technical expert triggers resolution

Use RAISE operation of class CL_PROXY_FAULT

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Asynchronous Services – Error and Exception Handling

Sender and receiver processfully decoupled Sender process may end before receiver starts Different LUWs, no two phase commit, no cross-system rollback

& locks No immediate resolution by sender possible

Errors detected by receiverto be handled independently from sender process

Error forward resolution necessaryIf possible error forward recovery

Out Out

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Suitable Error & Conflict Recovery Strategies

Different strategies to attempt error recovery possible

Suitable strategy depends on Kind of error / conflict

Categorization of errors & conflictsat design-time

Exact service & customer environment

Configurable determinationof recovery strategy

Automatic Manual Reject & delegate

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Asynchronous Service Execution –With Forward Error Handling

FEHLocal IEIntegration ServerService Consumer Service-enabledBusiness Logic

Service ImplementationInbound Service Proxy

<XML> Request</ XML>

Extended XML handling on

Error duringExecution

Rollback

Business Logic

Send RequestXML à ABAPTransformation Extended XML

handling off

ExecutionSuccessful

Pass input &error info to FEH

Register

Register FEH

Raise Exception

Start Reovery Process

Commit

Translate to API input paramsValidate params

Call pre-processing BAdI

Execute Business Logic

Input Parameters

Translate to ResponseCall post-processing BAdI

Result Parameters

Call Business Logic

Technical errors Fault

Messages

Scope of FEH

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FEH

Outbound Service Proxy

Service-enabledBusiness Logic

Service Implementation

Assemble Response

Response

Register outbound call

ExecutionSuccessful

Determine Strategy

Start Resolution Process

Commit

Translate to API input paramsValidate params

Call pre-processing BAdI

Execute Business Logic

Input Parameters

Translate to ResponseCall post-processing BAdI

Result Parameters

Call Business Logic

Retry

Manual completion/ Fail

Error during execution

Error occured in mapping

Error occuredin API

Sketch: Forward Error Handling Process

Different re-entry points conceivable

Service implementation not called by XI or WS runtime

callback operations IF_ECH_ACTION:

RETRY, FINISH, FAIL

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FEH Integration:Effort for Application Development

Separate service processing steps from inbound proxy class Required for automatic or manual re-execution

No XI or WS-RM runtime active

Call FEH, implement &register call-back interface (IF_ECH_ACTION) Ensure FEH is called at run-time if errors or conflicts are detected Call-back by FEH on retry requires implementation of defined interface



ABAP Payload

FEH Layer

Appl. Error Persistency



Determination

Post Processing

Office


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FEH Integration:Effort for Application Development (cont’d)

Categorization of errors & conflicts Assignment of messages to error symptom codes

Meta-data maintenance for FEH components Registration of service & call-back implementation

in ECH and PPO Configuration of retry-periodicity Optional: default configuration of resolution strategy



ABAP Payload

FEH Layer

Appl. Error Persistency



Determination

Post Processing

Office


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Asynchronous (inbound) Services – Single Service Tests

HTML client

Link

ABAP test report

available with SAP BS FND 7.01

HTML and ABAP client to be used for developer test (/SICF provides information regarding technical settings for the HTML client)

synchronous service execution using local IE full functionality of the local IE (including FEH) available test environment of SPROXY

Asynchronous outbound services must be reviewed in XI monitoring, if the message was correctly constructed

Wiki: test guideline

Documents

ABAP Backend Implementation of Asynchronous Services