SAP RFC Input and Output Adapter

The SAP Remote Function Calls (RFC) adapter is both an input and output adapter. The RFC Input adapter executes RFCs to import data from SAP systems into Event Stream Processor, while the RFC Output adapter exports data from Event Stream Processor into SAP systems.

Both adapters include an adapter configuration file and a mapping file. Use the adapter configuration file to set up the RFC Input and Output Transporter modules, the ESP Publisher and Subscriber modules, as well as establish a connection to Event Stream Processor. Use the mapping file to specify mapping definitions for RFCs, how ESP stream columns map to RFC parameters, how SAP table columns map to ESP stream columns, or how columns of the flattened data result set map to ESP streams.

Commands specified in the cnxml file for this adapter cannot contain the following strings: "mv", "rm", or "del".

You can either manually create a mapping file or use the schema discovery functionality in SAP Sybase Event Stream Processor Studio to automatically create one. See Discovering Schema and Creating a Mapping File for the SAP RFC Adapter in the Studio Users Guide for detailed instructions on creating a mapping file in SAP Sybase Event Stream Processor Studio.

These adapters can run in managed or unmanaged mode.

Managed external adapters:

Are started and stopped by the ESP Server with an ESP project.
Have a cnxml adapter configuration file that is configured within the ESP Studio.
Are referenced in a CCL ATTACH ADAPTER statement.

Unmanaged external adapters:

Start and stop independently of the ESP Server and ESP projects.
Are configured independently.
Are not referenced in a CCL ATTACH ADAPTER statement.

The RFC Input adapter:

Executes selected RFCs at predefined interval and publishes the retrieved data to streams and windows in Event Stream Processor
Operates in three modes: generic RFC (includes RFC chaining capabilities), read table, and BW

The RFC Output adapter:

Maps data from ESP streams and windows to input parameters when RFCs are invoked
Operates in generic RFC mode only

The RFC Output adapter also supports guaranteed delivery (GD). It can batch up ESP data rows in the RFC parameter list and submit the data in a single RFC call. The <BatchSize> configuration parameter controls how many ESP data row the adapter batches before invoking the RFC.

Batching makes sense for an RFC that builds up table parameters from ESP column data so as to cut down the number of RFC calls involved. If data is mapped to non-table type parameters, values are overwritten as new ESP data rows are processed, so only use batching when data is treated as data rows in a table parameter.

The RFC Input and Output adapters report custom statistics. Enable the time-granularity option in the project configuration (ccr) file to get these statistics reported by the _ESP_Adapter_Statistics metadata stream.

The RFC Input adapter reports these statistics:

AdapterRunningTime
TotalInputRowsNumber
SuccessInputRowsNumber
ErrorInputRowsNumber
InputLatency

The RFC Output adapter reports these statistics:

AdapterRunningTime
TotalOutputRowsNumber
SuccessOutputRowsNumber
ErrorOutputRowsNumber
OutputLatency

Generic RFC Mode
Both the RFC Input and Output adapter operate in generic RFC mode. This mode includes any RFCs available from the SAP system to which you are connecting the adapter.
RFC Chaining
While in generic mode, the RFC Input Adapter can invoke multiple RFCs in sequence. This is called RFC chaining.
Read Table Mode
The read table mode invokes the RFC named RFC_READ_TABLE which retrieves columns of a specified SAP table and returns the data as a result set.
BW Mode
In BW mode, the adapter submits MDX (multidimensional expression) statements against defined BW queries (cubes).
Control Flow
The RFC adapter loads its configuration from a file (for example, adapter_config.xml) and validates it against the adapter schema (framework.xsd). The framework.xsd file is used by the adapter toolkit, which the adapter is based on, to check for things like missing elements, invalid value types, and so on.
Message Flow
When the SAP RFC adapter is started, it establishes a connection to an SAP system.
Enabling the RFC Adapter
If you plan to use the RFC adapter, you must copy some files from the SAP Java Connector (JCo) 3.0.9 to your Event Stream Processor installation.
Managed Mode Configuration
To start and stop the adapter with an ESP project, attach it to a project using the ATTACH ADAPTER statement and configure its properties using the ESP Studio.
Unmanaged Mode Configuration
To start and stop the adapter independently of an ESP project, do not reference it in an ATTACH ADAPTER statement, and configure it independently outside of the ESP Studio.
Starting the SAP RFC Adapter
Start the RFC adapter either in unmanaged or managed mode. In unmanaged mode, the adapter is started separately from the ESP project, and in managed mode, the adapter is started with the ESP project. In unmanaged mode, you can start the adapter from the command line or using the start command files.
Stopping the RFC Adapter
Stop the RFC adapter either in unmanaged or managed mode. In unmanaged mode, the adapter is stopped separately from the ESP-short-name project, and in managed mode, the adapter is stopped with the ESP-short-name project. To stop the adapter from the command line, execute the stop or immediatestop command. The immediatestop command stops the adapter without waiting for any unprocessed records to finish processing..
Logging
The SAP RFC Input and Output adapter use the Apache log4j API to log errors, warnings, and information and debugging messages. A sample log4j.properties file containing the logging configuration is part of the SAP RFC Input and Output adapter distribution.
Adapter Controller Parameters
The Adapter Control port listens for commands. The controller.xml file is located in %ESP_HOME%/adapters/framework/config directory. This file is shared among all the adapters within the %ESP_HOME%/adapters/framework/instances directory.
RFC Adapter Directory Reference
The rfc directory contains configuration files, templates, and examples relating to the adapter.
Mapping File for Generic RFC Mode
The mapping file for the RFC Input adapter running in generic RFC mode specifies mapping definitions for RFCs. The mapping file for the RFC Output adapter running in generic RFC mode specifies how ESP stream columns map to RFC parameters.
Mapping File for Read Table Mode
The mapping file for an RFC output adapter running in read table mode contains fieldMapping entries that specify how SAP table columns map to ESP stream columns.
Mapping File for BW Mode
The mapping file for an RFC input adapter running in BW mode contains entries for specifying how columns of the flattened data result set map to ESP streams.
Datatype Mapping for the SAP RFC Output Adapter
Event Stream Processor datatypes map to SAP ABAP datatypes.
Datatype Mapping for the SAP RFC Input Adapter
Event Stream Processor datatypes map to SAP ABAP datatypes.

Parent topic: Adapters Currently Available from SAP

Related concepts

Guaranteed Delivery and Persistent Subscribe Pattern

Related reference

Adapter Support for Schema Discovery