17 4 Using LANSA SuperServer

LANSA Application Design

17.4 Using LANSA SuperServer

Finally there is the LANSA SuperServer client/server model that the LANSA supports.

Since LANSA for iSeries can create OAMs (IO Modules) functionally identical to those it creates under Visual LANSA, this special or "enhanced" client/server model can be supported.

Note: LANSA SuperServer can also be used to access databases on a Windows platform. The benefits described here for IBM i also apply to those platforms.

Some of the more important facilities that this model provides are:

  • Application Security
    All access requests are subjected to the same set of authority checks as normal IBM i applications.
  • Application Integrity
    All access requests are subjected to the same set of validation rules as normal IBM i applications.
  • Performance
    This client/server model offers good client/server performance for two main reasons:
  • It is specifically optimized for IBM i processing.
  • The OAM (IO Module) architecture complements the LANSA Data Dictionary. e.g. When an "INSERT" request requires several database validations and fires an event trigger it is all initiated by just one simple Client request. The level of traffic between the client and server is minimized.
  • Multiple Connections
    This model allows an application to connect to multiple IBM i databases simultaneously.
  • Simplicity and Cost
    There is no extra software or cost for each PC accessing an IBM i server this way. The IBM i server needs a single "LXX" (LANSA SuperServer) license. There are no extra install procedures and the connections are all via standard Windows based communication routers.
  • Compatibility and Reversion
    This model is fully supportive of, and complementary to, the DDCS/2 DRDA/ODBC models. In fact you can, at any time, drop this model and revert to the DBRA/ODBC model without any need to change your application design.
  • Remote Procedure Calls (RPCs)
    This model has a Built-In Function named CALL_SERVER_FUNCTION that allows you to call a function on the server. Parameters and lists can be passed to and from the server function.
    The presence of an RPC capability is probably the most important component of a client/server model. You will find that you cannot possibly create an application system where all components run on the client system CPU(s). There will be many activities that have to be performed on the server.

The LANSA SuperServer client/server model is supported by these Visual LANSA Built-In Functions:

DEFINE_OS_400_SERVER

Define an IBM i server machine.

DEFINE_OTHER-SERVER

Define other server.

CONNECT_SERVER

Connect to a server.

DISCONNECT_SERVER

Disconnect from a server.

CONNECT_FILE

Connect a file to a server.

DISCONNECT_FILE

Disconnect a file from a server.

CALL_SERVER_FUNCTION

Call a function on a server.

 

For full technical details refer to Built-In Functions in the LANSA Technical Reference Guide.