Since the 1990s, the calculation industry has been using object-oriented middleware platforms like DCOM and CORBA. Object-oriented intermediates is a very important step in the process of making distributed computing to applying developers. Developers have the first time you have this possible: You don't have to be a network Guru, you can build a distributed application - the middleware platform will take place to take advantage of most of the network hybrids, such as the Marshaling and UNMARING. The data is encoded and decoded for transmission), mapping the logical object address to the physical transmission endpoint, changing the data representation according to the original machine architecture of the client and server, and the server should be automatically started. However, due to some reasons, both DCOM or CORBA failed to successfully occupy most of the calculation markets:
l DCOM is an exclusive solution for Microsoft. In the heterogeneous network, various machines run multiple operating systems and cannot use DCOM.
l DCOM cannot support a large number of objects (hundreds of thousands or millions), which is largely due to its distributed garbage collection mechanism.
l Although there are several suppliers to provide CORBA products, it is almost impossible to find a supplier that can be implemented for all environments in the xenograft. Despite a large number of standardization, different CORBA implementations are still lack of interoperability, thereby constantly causing various problems; and because suppliers often define their own expansion, CORBA lacks specifications for multi-threaded environments. Source compatibility like C or C , source compatibility is not fully implemented.
l DCOM and CORBA are too complicated. To be familiar with DCOM or CORBA, and carry out the corresponding design and programming, it is a difficult task that needs to be mastered in many months (but to reach an expert level, take for several years)
l In its respective history, performance issues have been torture these two platforms. DCOM has only one implementation available, so it is impossible to purchase better purchase performance. Although there are several suppliers offered
Corba products, it is difficult to find compliance standards, good performance - its main reason is the complexity of the CORBA specification itself (in many cases, its characteristics are abundant)
l In a heterogeneous environment, the DCOM and CORBA have never been an easy task: Although there is a supplier to provide interoperability products, the interoperability between the two platforms has never seamless, and it is difficult to manage, will Generate technology is island that is not connected to each other.
In 2002, Microsoft .NET platform [11] replaced DCOM. However, although .NET provides more powerful distributed computing support than DCOM, it is still a exclusive solution for Microsoft, so it is not a choice of choices. On the other hand, CORBA has been stagnant in recent years, many suppliers have left the market, leaving the platform for consumers, no longer being widely supported; the remaining minority suppliers have declined in further standardization, causing Many of the shortcomings in the CORBA specification have not been resolved, or they are resolved after they have been reported for many years. While DCOM and CORBA decline, distributed computing communities have a strong interest in SOAP and Web Services. Using an ubiquitous WWW infrastructure and HTTP to develop the idea of middleware platforms - at least in theory. SOAP and Web Services have promised to become a distributed computing generic language on the Internet. But despite a large public effect, many papers have been published, and Web Services cannot be fulfilled: the business system developed by Web Services architecture is very small while writing. The reason is: l Whether in terms of network bandwidth, SOAP will cause serious performance to deteriorate, so that this technology cannot be applied to many systems with harsh performance requirements.
l Although SOAP provides the "ON-THE-WIRE" specification, it is still not enough to develop real-world applications, because the abstraction level provided by this specification is too low. The application can put all kinds of SOAP messages together, but this is extremely cumbersome and wrong.
l The lack of more advanced abstraction enabling suppliers to provide a variety of application development platforms to automate the application development of SOAP. However, in addition to the primary level, these development platforms are completely free of standardization, inevitably private, so the applications developed with a supplier cannot be used with the middleware products of other suppliers.
l About SOAP and Web Services architectural security, there are some serious concerns. In particular, many experts say they are worried about the lack of intrinsic security of the platform. DCOM and CORBA are too complicated. To be familiar with DCOM or CORBA, and carry out the corresponding design and programming, it is a difficult task that needs to be mastered in many months (but to reach an expert level, take for several years)
Web Services is a technique that is still in the young. So far, it has been standardized, and it takes several years that it takes several years, and its standardization level can reach the intensity of source compatibility and interoperability across the supplier. As a result, developers who want to use the middleware platform face some unhappy choices:
l net
The most serious disadvantage is that non-Microsoft platforms are not supported.
l Corba
The most serious disadvantage is that aging platform, high complexity, as well as suppliers that are still occurring.
l Web Services
The most serious disadvantages are serious and inefficient and need to use private development platforms, and there is still security issues.
These choices seem to make you fail: You can choose the platform that can only run on the Microsoft architecture, select complex, abandoned platforms, or choose to be inefficient, due to lack of standardization, private platforms.
ICE (Internet Communications Engine) is a new generation of object-oriented middleware developed by the former CORBA expert Marc Laukien, Michi Henning and Matthew NewHook, has been used as a large online game wish (
Www.wishgame.com) Communication Engine. According to Zeroc, ICE is "a modern object-oriented middleware that can be used to replace middleware like CORBA or COM / DCOM / COM . While easy learning, it is a variety of demanding technical requirements. A powerful network infrastructure is provided. It is too slow in technology like SOAP or XML-RPC, or does not provide sufficient scalability or security. It is the ICE to start shining. "And if you look at ICE "Millennium Corba, throws away the burden accumulated in its life, but it retains its full good characteristics, add some characteristics, and designs them in a clear and tidy manner", perhaps more You grasp the nature of the ICE.
For more information on ICE, you can refer to the following information:
* Rebellion Ice: Internet Communications Engine -
http://blog.9cbs.net/grhunter/archi...7/20/45606.aspx
* The father of ICE arrived in Beijing to explain high performance network computing engine -
http://www.9cbs.net/news/newstopic/16/16366.shtml
* 2004 No. 9 ICE topic on "programmer" magazine -
http://mag.9cbs.net/content.aspx?id...dd-0b3e55740577
