Rfc sdk guide CPIC_MAX_CONV

The RFC clientIs the instance who callthe remote function module, which is providedAn RFC server.

 

The RFC client remotely calls the function module provided by rfcserver.

 

The RFC callare accomplished via an RFC connection. Up to 100 (default value) Active RFC connections at a time are possible. This value can be changed by using environment variable cpic_max_conv.

 

An RFC connection is required for an RFC call. At the same time, up to 100 active contacts are allowed by default. This value can be controlled by modifying the environment variable cpic_max_conv.

There are two types of RFC connections:
• Client connection.
• Server connection.

Sometimes the server connection is called accepted connection.

 

There are two types of RFC connections:

Client Connection

Server connection

Sometimes, the server connection is obtained by accepting the connection.

An RFC handle represents an RFC connection. Technically a handle is an index of an internal memory structure, which contains necessary information about given RFC connections. An RFC handle is an instance of Type rfc_handle.

An RFC handle references an RFC connection. Technically, a handle is an index of the memory structure that includes RFC connection information. An RFC handle is an rfc_handle-type instance.

There are two kinds of RFC handles:
• Invalid RFC handle. This is either an RFC handle with value rfc_handle_null or an already closed or aborted RFC connection. It is impossible to make any API call via this handle.
• Valid RFC handle. API callhave to be done by using a valid RFC handle. A try to call any API-function with an invalid handle causes an error with return code rfc_invalid_handle.

 

There are two types of RFC handles in the system:

Invalid RFC handle. When the handle value is rfc_handle_null or a closed and aborted RFC connection handle. In this case, you cannot use this handle to call any API.

Valid RFC handle. An API call must use a valid RFC handle. An RFC_INVALID_HANDLE error is returned when an API call with an invalid handle is used.

RfcGetAttributes API delivers the user relevant data describing a given RFC connection.

 

You can call the RfcGetAttributes API to obtain the description of a specified RFC connection.

During execution of an RFC function at the server side, it is sometimes useful to call another RFC function in the original (client) system. for example, if one needs data from the caller before continuing with the current RFC function. this behavior is called call back feature in SAP jargon. the RFC server uses the same RFC connection established by the client and Calla remote function at the client side. the call back hit the same context in R/3 system. RFC Library supports a call back mechanisms for client and server. it is not necessary to open a new connection, I. e ., the same RFC handle will be used.

 

When the RFC function is executed on the server, the original system sometimes needs to call other RFC functions. For example, the current RFC function needs to obtain relevant data from the caller to continue execution. This is the callback feature in SAP system terminology. The RFC server uses the same RFC connection established by the client and calls functions from the client. The callback has the same R/3 System context. The RFC Library supports callback between clients and servers. In this case, you do not need to open a new connection, that is, you can use the same RFC handle.