Experience the distributed programming
Redstar81 at 9/9/2003 ~ 13/9/2003 81_redstar81@163.com Tomhornson.student@www.sina.com.cn
First modification time: 13/9/2003 personal text: http://www.9cbs.net/develop/author/netAuthor/redstar81/
Second, the introduction of several excellent distributed computing platforms
Below we briefly introduce several excellent distribution computing platforms to prepare for the following programming. Want to learn more about related technologies, please refer to special books.
Corba (Common Object Request Broker Architecture)
CORBA is an industrial specification developed by the Object Management Organization (OMG). It is built on OMA. Providing a public architecture for object-oriented applications, if this framework can be established on major hardware platforms and operating systems. The original intent is to provide a mechanism, on this, on this, the object can be transparently issued and responded. Typically, you can use ORB (herein, refer to the core framework of CORBA): Object service, public facilities, domain interface, application object. The current CORBA implementation is on the object attempt, which is basically using the stub and skeleton technology, and is processed by the actual work of the ORB infrastructure to realize the pilot of the object application. From this point, it is similar to the principle of DCOM. Another problem we need to pay attention is: Natural CORBA is just a norm, then communication between various implementations will inevitably have problems. CORBA 2.0 gives an ORB interoperability protocol: Giop (Global Inter-ORB Protocol) and IIOP (Internet Inter-ORB Protocol), environmentally specific ORB communication protocol: ESIOP. In fact, in the face of the widespread application of MS COM / DCOM, a large number of research in OMG is also invested to implement DCOM / CORBA interaction communication.
Based on CORBA development, the most important thing for development tools is to implement maps of IDL and specific languages. Current CORBA development native language is C and Java. More famous products are: Iona Orbix (Based on C ) and ORBIX Web (based on Java). Visigenic Software's Visibroker (Based on C ). Diagital / BEA's Object Broker.ibm's DSOM.
2.Jini
Jini is a Java-based distributed computing platform released by Sun. The goal of the JINI system is to provide resources in all heterogeneous networks in a unified view and assure the system's scalability / dynamics. JINI's basic components are: infrastructure / programming models and services. JINI's core concept is: service. Everything is a service. For services, several important concepts are: Service Publish / Services Find / Rent / Transaction / Events /. They achieve all the feasible operations of the service. JINI underlying communication is based on RMI. RMI provides a mechanism to discover / activate and collect useless objects, and RMI also provides multipoint broadcast / replication and basic security and confidentiality. Strictly speaking, RMI is the Java implementation of RPC, but it can achieve data and code movement due to the unique language of Java itself.
3.WebServices
WebServices is the latest distributed computing platform, like Jini, advocating the idea, release / find / rental services, WebServices, the most eye-catching, it is possible to use a new protocol: SOAP (Simple Object Access Protocol) . SOAP is a lightweight application layer protocol based on HTTP and XML. The traditional RPC is based on binary data stream. This stream often cannot pass firewall from system robustness. This will bring a big problem to the distribution system. Second, SOAP is based on XML, from multi-layer architecture Say, it greatly simplifies the data processing process, because if all subsystems in the system architecture support XML, it is clear that data conversion operations will decrease in the data stream process. WebService programming model: business release service, partner Discover services and integrate into the system you develop. Thewebservices architecture should also include a set of Server APIs to help Webserve Server extension development, and a group of Client APIs used to help client development.
4.Voyager
Let's introduce a distributed computing platform that is not very well known: Voyager. This platform is the most powerful platform I have ever seen. It is the banner of the US Objectspace. The third generation of products has been knotted It became RMI / CORBA / DCOM, and can generate a proxy for remote objects at runtime, which does not require RMIC or the enhanced RMIC: VCC: VCC. Overall, Voyager's functionality is as follows:
1) Remote objects.
Based on Voyager, you only need to generate a local object first, then call proxy.of (Object Obj) to get an object that can be called remotely. In RMI or other distribution object technology, it is generally required to implement the remote interface. Then, then generate a skeleton by a compiler, where the Server-end agent is dynamically generated at runtime.
2) Remote reference
3) Remote object generation
This is a function that maybe you think that it is incredible, and the client can generate an object on the remote server.
4) Abnormal handling
In the Voyager system, exceptions are not processed remotely. This increases the security performance of the system.
5) Name Service
6) Distributed garbage collection
Objects can be reclaimed only when the object's local and remote references do not exist.
7) Object migration
You know that the Java code can be migrated, but the object is not migrated, but Voyager can make your dreams into reality. This is a very exciting function.
8) Mobile agent
Object movement autonomy. Supports IBM Agelets programming.
9) Communication for Applet and Applet
Strictly speaking, Applet can only communicate with its host host, then Voyager allows you to design a contact center on the server to implement communication between Applets on different machines.
10) Group communication
Publishing using multicast technology or event-driven release - subscription apps can be easily implemented. This is a bit like object space technology in Javaspace, but it is more powerful and complicated.
11) activation
Those objects in the remote object database can be automatically reactivated and loaded into memory.
12) Distributed persistence independent of the database
Voyager's persistence of data through VoyagerDB technology.
13) ORB
Voyager has an ORB that can be integrated with other distributed systems.
14) CORBA
15) RMI
16) DCOM
I didn't, if you have been excited for DCOM / RMI / WS, then I think you will really like this name from Texas, Satan (Sun / IBM, has been shocked by this product) . In fact, based on this system, there is also a more beautiful design of the virtual floor design for native distributed language dejay. You can get this product from www.objectspace.com.
to be continued:
Three. Review of several distributed object computing technology
Four. Recommendations of several distributed languages
PART2. Practice
V. Distributed Programming Practice
Objectspace Voyager
2. DCOM
3. CORBA
4. WebServices
5. Sun RMI vs. DotNet Remoting6. Linda and Sun Javaspace, IBM TSPACE
7. Jini
8. Emerald vs. dejay
9. Pjama
10. IBM Mobile Computing Interface: Aglets
6. Comprehensive application analysis
1. Calculate technology to simulate high performance parallel computing with multi-threaded and distributed objects
2. Calculate geometric fractal graphs using Vdejay
statement:
1. I am not specializing in the distribution, completely written down this article. I will help distributed computing applicants. 2. Welcome to the level, welcome to correct. 3. Since this paper tells more content, many tells that it is impossible to be too meticulous. And taking into account the problem of the reader group, the theoretical content is omitted as much as possible. If the reader is interested, you can refer to the list of reference books and network resources.
4. Arbitrary reproduced, but please indicate the source; not available for commercial purposes.
