What is Sync/Async processing and Updates ?

[Former Member]

Hi SAP-ABAP Experts .

Please explain me about thses queries regading BDC's...

What is Sync/Async processing and Updates ? Can we visually see them ?

(1.) Session Method have Syncronous Prosessing or Asyncronous Prosessing ?

(2.)Session Method have Syncronous Update or Asyncronous Update ?

(3.)Call Transection Method have Syncronous Prosessing or Asyncronous Prosessing ?

(4.)Call Transection Method have Syncronous Update or Asyncronous Update ?

(5.)How to handle Errors in Call Transection Method through BDCMSGCOLL ?

(6.) May u plz explain me what is diffrence b/t Syncronous Prosessing and Asyncronous Prosessing ?

Which is faster ?

(7.) May u plz explain me what is diffrence b/t Syncronous Update and Asyncronous Update ?

Which is faster ?

Best Regards : Rajneesh

[Former Member]

Hi

(1.) Session Method have Syncronous Prosessing or Asyncronous Prosessing ?

(2.)Session Method have Syncronous Update or Asyncronous Update ?

(3.)Call Transection Method have Syncronous Prosessing or Asyncronous Prosessing ?

(4.)Call Transection Method have Syncronous Update or Asyncronous Update ?

(6.) May u plz explain me what is diffrence b/t Syncronous Prosessing and Asyncronous Prosessing ?

Which is faster ?

(7.) May u plz explain me what is diffrence b/t Syncronous Update and Asyncronous Update ?

Which is faster ?

Database changes that are made via the SAP Update System and transferred to an update work process, can be carried out synchronously or asynchronously. The mode is specified in the ABAP source code of the SAP transactions and cannot be changed dynamically by the user.

The SAP transaction creates an update request with CALL FUNCTION … IN UPDATE TASK, and transfers this to an update work process. Data is then written to the update tables at the end of a database LUW.

With synchronous updates, the program that outputs the statement COMMIT WORK AND WAIT waits until the update work process outputs the status of the update. The program can then respond to errors separately.

With asynchronous updates, the program that outputs the statement COMMIT WORK passes the update onto the Update System and does not wait for the update process to respond.

(5.)How to handle Errors in Call Transection Method through BDCMSGCOLL ?

Create a internal table TYPE bdcmsgcoll.. ,

In the CALL TRANSACTION statement, u define the Internal table of BDCMSGCOLL say MESSTAB.. .

Check for sy-subrc after the CALL TRANSACTION Statement..

If Sy-subrc NE 0..

Read the Message table T100 for the Message.. With the Message ID from MESSTAB..

Some More Info on :

Session method.

1) synchronous processing.

2) can tranfer large amount of data.

3) processing is slower.

4) error log is created

5) data is not updated until session is processed.

Call transaction.

1) asynchronous processing

2) can transfer small amount of data

3) processing is faster.

4) errors need to be handled explicitly

5) data is updated automatically

Batch Data Communication (BDC) is the oldest batch interfacing technique that SAP provided since the early versions of R/3. BDC is not a typical integration tool, in the sense that, it can be only be used for uploading data into R/3 and so it is

not bi-directional.

BDC works on the principle of simulating user input for transactional screen, via an ABAP program.

Typically the input comes in the form of a flat file. The ABAP program reads this file and formats the input data screen by screen into an internal table (BDCDATA). The transaction is then started using this internal table as the input and executed in the background.

In ‘Call Transaction’, the transactions are triggered at the time of processing itself and so the ABAP program must do the error handling. It can also be used for real-time interfaces and custom error handling & logging features. Whereas in

Batch Input Sessions, the ABAP program creates a session with all the transactional data, and this session can be viewed, scheduled and processed (using Transaction SM35) at a later time. The latter technique has a built-in error processing mechanism too.

Batch Input (BI) programs still use the classical BDC approach but doesn’t require an ABAP program to be written to format the BDCDATA. The user has to format the data using predefined structures and store it in a flat file. The BI program then reads this and invokes the transaction mentioned in the header record of the file.

Direct Input (DI) programs work exactly similar to BI programs. But the only difference is, instead of processing screens they validate fields and directly load the data into tables using standard function modules. For this reason, DI programs are much faster (RMDATIND - Material Master DI program works at least 5 times faster) than the BDC counterpart and so ideally suited for loading large volume data. DI programs are not available for all application areas.

Differences between bdc session method and call transaction method.

The most important aspects of the batch session interface are: - Asynchronous processing - Transfers data for multiple transactions - Synchronous database update During processing, no transaction is started until the previous transaction has been written to the database. - A batch input processing log is generated for each session - Sessions cannot be generated in parallel

The most important aspects of the CALL TRANSACTION USING interface are: - Synchronous processing - Transfers data for a single transaction - Synchronous and asynchronous database updating both possible The program specifies which kind of updating is desired. - Separate LUW for the transaction The system performs a database commit immediately before and after the CALL TRANSACTION USING statement. - No batch input processing log is generated.

Batch Input Session:

It is a sequence of transactions, which is generated when user run a particular program.

It contains the accounting documents that are to be created. The SAP system stores these transactions until you decide to process them online.

It does not update transaction figures until the session has been processed. Using this technique, you can transfer large amounts of data to the SAP system in a short time.

Three processing modes of executing Batch Input Session :-

(1) Run Visibly : You can correct faulty transactions online & work step-by-step through the transactions not yet executed.

(2) Display Errors only : You can correct faulty transactions online. Transactions not yet executed, but without error, run in the background.

(3) Run in Background : Recommended by SAP

Reward Point If useful