Server Connectivity

Server application must provide access to a variety of knowledge sources & not be restricted to vendor-supplied sources. This connectivity is in part due to vendors "opening" up access to their knowledge structures by application program interfaces.

Knowledge gateways provide access to outside databases. Most database gateways use structured query language as the access language. With a simple pass-through database gateway have application on both the sending & receiving nodes.

This allows the application to optimize the query & supports portability but does not permit the use of any special features that might be in the structured query language of the target database. Microsoft's Open Database Connectivity (ODBC) application program interface permits applications to communicated with relational & now-relational knowledge sources. Open Database Connectivity, compared to proprietary database management method.

It is based on the call-level interface developed by the structured query language access group. Open database connectivity drivers permit developers to write windows-based applications that transparently access the knowledge sources supported by the drivers. Announced open database connectivity drivers include links to structured query language server from knowledge builders, Incorporated.

Remote Procedure calls:

Designing client/server applications is fundamentally different then building traditional mainframe or macro-based micro applications. Programmers ought to be isolated from network intricacies & given simple access to network functions. Remote procedure calls & message queuing systems provide this service.

Remote procedure calls are currently more widely used than message queuing systems. Remote procedure calls, which are application program interfaces layered on top of a network inter-process communication mechanism, permit servers to communicate directly with each other.

They permit individual processing parts systems; method management, security, & application programming depend on the capabilities of the underlying remote procedure call mechanisms. Server access control & the use of a listing service are common needs that can be met with remote calls.

Remote procedure calls also manage the network interface & handle security & listing services. The paradigm of using high-level languages to call procedures is not new. A remote procedure call ought to look & act likes a local procedure call to the programmer. The idea is to spread work & knowledge over the network to optimize resources.

Remote procedure call tools usually include:

1. A language & a compiler that can be used to produce transportable source code.

2. A run-time facility that makes the method architecture & network protocols transparent to the application procedures.

Sun soft's general-purpose Transport-Independent Remote Procedure call toolkit is based on source-code generation expertise from Net wise incorporated. The application allows application developers to generate a single version of a client/server application that will run unmodified across a range of operating systems, hardware bases & networks such as TCP/IP, OSI Net Ware's IPX.

It’s major limitation? They usually require synchronous connections. If an application makes use of a procedure call to link to a server that is inoperable or busy, the application will wait for the knowledge than moving to other tasks.