What is Middleware?
- Middleware does not include the software that provides the actual service that’s in the server’s domain.
- It also does not include the user interface or the application’s logic that’s in the client’s domain.
- It starts with the API set on the client side that is used to invoke a service, and it covers the transmission of the request over the network and the resulting response.
- Middleware divided into two broad classes:
(a) General Middleware (b) Service-Specific Middleware
(a) General Middleware
- It is the substrate for most client/server interactions
- It includes the communication stacks, distributed directories, authentication stacks, distributed directories, authentication services, network time, remote procedure calls, and queuing services.
- Products that fall into the general middleware category include DCE, ONC+, NetWare, NamedPipes, LAN Server, LAN Manager, Vines, TCP/IP, APPC and NetBIOS.
- Message Oriented Middleware (MOM) products from Peerlogic, Covia, Message Express, System Strategies and IBM.
- These are depends on message queue system and increases portability, interoperability, flexibility.
(b) Service-Specific Middleware
- It is need to accomplish a particular client/server type of service.
- This includes
- Database-specific middleware such as ODBC, DRDA, EDA/SQL, SAG/CLI and Oracle Glue.
- OLTP-specific middleware such as Tuxedo’s ATMI and /WS, Encina’s Transactional RPC, and X/Open’s TxRPC and XATMI
- Groupware-specific middleware such as MAPI, VIM, VIC, SMTP and Lotus Notes Calls
- Object-specific middleware such as OMG’s CORBA and Microsoft’s Network OLE (or DCOM)
- Internet-specific middleware such as HTTP, S-HTTP and SSL
- System Management-specific middleware such as SNMP, CMIP and ORBs.
