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CLIENT/TRANSACTION SERVICES |
| Client/transaction services are favored for high performance OLTP
(on-line transaction processing) applications. Typically, the application program is split
between a workstation client and a host server, though this model also applies to host
client/host server and host client/workstation server architectures as well. The client side of the application is generally responsible for presentation services, editing of incoming data from the user, and formatting of outgoing data to the user. The server side is responsible for the business logic governing database access and update. The client/transaction model is highly efficient and highly interactive, since a single transaction sent over the network can encompass a significant amount of database activity. However, the application must be totally defined in advance. This is, of course, the realm of OLTP. These services also are available for peer-to-peer application communication in which two applications must communicate as equals. Either application may send a message to the other with or without the requirement for a reply. | |
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MESSAGE QUEUING SERVICES |
| Many distributed processing requirements involve communication between peer applications, in which neither application is a server to the other. These applications do not require interaction; instead, they require a guarantee that each message will be delivered ultimately to the receiving application even if the receiving platform or communication network is currently down. Typical examples of these applications are: This is the realm of message queuing services. With NetWeave's queuing services, each message is safely stored in a FIFO (first in, first out) file by the sending application, from which it can be read at the receiver's convenience. The FIFO file may be located on any platform in the network. It is typically located on the sending platform or on some other fault-tolerant platform in the network.
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MESSAGE BROADCAST SERVICES |
| Using NetWeave, an application may
broadcast a single message to multiple remote applications. If the
interconnecting network supports a broadcast function (such as UDP/IP), then NetWeave
need send only a single message. Otherwise, the message will be multicast
individually to each recipient. NetWeave's broadcast services are useful to synchronize applications. For instance, a periodic time message may be sent or a notification that trading is opened or closed. These broadcast services are fundamental to NetWeave's data replication services.
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CLIENT/DATABASE SERVICES |
| Client/database services represent a highly flexible approach to
ad hoc applications which cannot be clearly defined in advance.
They are also useful when the database platform is closed to new application programs or
when the cost or schedule for deploying new applications on the database platform is
prohibitive. Under this model, the application as a whole acts as a client to a remote NetWeave database server. The client application can manipulate records in proprietary files or can manipulate rows in SQL data bases managed by the database server just as if that data were local to the client platform. The advantage of this model is that new applications can be written solely on the client system, with no knowledge needed of the inner workings of the database server. However, each database operation (open, position, read, update, select, fetch, etc.) must be sent individually over the communication network. Client/database services are useful in many non-OLTP and light OLTP applications, such as:
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TRANSACTION SERVICES |
| Transaction services are used by a client application to bound a series of updates to a remote data base. By starting a transaction and subsequently committing it, all intervening updates are guaranteed to be made to the data base, or else none are made. Thus, the data base will always be left in a consistent state. Transaction protection is available for Client/Transaction, Client/Database, Message Queuing, and Replicated Data Services. | |
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DATA CONVERSION SERVICES |
| Data conversion services are used to reconcile differences in data formats between diverse platforms. A NetWeave application can ask the type of a remote platform and can then use NetWeave's data conversion services to translate data from server format to client format and vice versa. | |
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SECURITY SERVICES |
| Security services offered by NetWeave provide controlled access to a server platform by using a challenge/response protocol. An application may provide its own level of security by incorporating a user-supplied security function. When a client application first attempts to use a server, it must provide a valid identification. It then must respond properly to a challenge issued by the security server. The challenge can be anything from a simple request for a password to a random token requiring a computed response. | |
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DIRECTORY SERVICES |
| Directory services allow a client to access a remote file, a remote table, or a remote process without having to know where that object is physically located in the network. The client application need only know the object by a pseudonym, such as the PAYROLL file. When the object is opened by the client application, NetWeave will use the directory services to locate the object in the network and to determine the proper naming semantics for referring to that object. | |
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FILE TRANSFER SERVICES |
| File Transfer Services - (change title to all caps, just like your other categories). File transfer services can be used to transfer files between systems. Any platform can initiate a file transfer with a remote platform, and the file may be transferred in either direction. A file transfer may be initiated either programmatically or manually. | |
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REMOTE SPOOLING SERVICES |
| Remote spooling services allow a file to be sent to a spooler on a remote platform for later delivery to a printer, a file, or a process. Full advantage can be taken of the remote spooler's capabilities, such as distribution, banners, and copies. | |
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DUAL LAN SUPPORT |
| For LAN users, maintaining high visibility of LAN-connected applications is a never-ending battle. In many vertical applications, the loss of an application due to a LAN failure can prove expensive. NetWeave now solves this problem with its new dual LAN support. Using NetWeave, workstations involved in mission-critical applications can be connected to their servers and hosts not by one, but by two LANs. Under normal circumstances, NetWeave will use both LANs. But should one LAN fail, NetWeave will continue to use the good LAN and will monitor the failed LAN to see when it is returned to service. This all happens automatically, unbeknownst to the users of the system. | |
Middleware Services
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