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Java 2 Bible Enterprise Edition phần 10

Chương 24: Kiến trúc hệ thống Các vấn đề Hãy nhớ rằng mặc dù J2EE là một bộ sưu tập lớn các chức năng, nó sẽ không giải quyết mọi vấn đề trên thế giới, khá thường xuyên, bạn sẽ cần phải sử dụng hệ thống sở hữu độc quyền. ứng dụng Tuxedo của BEA. Tuxedo là một tiền thân của các hệ thống J2EE | Chapter 24 System Architecture Issues Remember that although J2EE is a great collection of functionalities it won t solve every problem in the world quite frequently you will need to use proprietary systems. One of the more common you are likely to come across is BEA s Tuxedo application-server software. Tuxedo is a precursor to the J2EE systems and has many things in common with them. Deploying the system With the application completed you need to start deploying it into the real world. Following the line of thought we have been presenting so far the hardest way for you to deploy an application is to rock up right at the end of the project and dump it into the customer s lap. No matter how heavily you test the application in your development the real world will always produce more problems. Why not try to get bits of the application onto the customer s site as early as possible In this way you can fight the small bugs right at the front before they compound into impossible-to-deal-with monsters hidden in a huge collection of code. Each time you add a new piece to the customer s version of the code new bugs can only come from that small area. Tracking them down should be much more manageable with a small chunk of code than with one monolithic lump. Dividing up the Workload By its very nature J2EE encourages you to build highly modular systems. Of course the word enterprise in its name also suggests that the main focus is on large application areas. When you put these two thoughts modularity and large systems read scalability together it should become immediately apparent that you are going to need more than one box to put all this code on. When you have to deal with the multiple computers containing your code you must consider many other issues. Do you have many small computers serving up your business functionality or a couple of big ones If you have many small computers how do you divide the code among them These are all issues that you may have to deal with as a