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This article introduces the knowledge of "introduction of CICS and MQ middleware". Many people will encounter this dilemma in the operation of actual cases, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

CICS (customer Information Control system) is the transaction processing software of IBM Company, which has a history of more than 26 years. The transformation from batch operation mode to online transaction processing mode makes people realize that there must be special transaction processing software to schedule the operation of transactions in order to obtain satisfactory system performance and transaction reliability.

The development of a large online transaction processing system is much more complex than most people originally imagined. It is by no means as simple as putting the data in a host database and then developing some client programs to access and modify the data.

The greatest contribution of CICS is an in-depth analysis of the common requirements in the online transaction processing system that have nothing to do with business logic but only related to the operation of the system, summarize the above complex software functions, help applications achieve these functions in the form of servers, and act as application management in the running process of the whole system, analogous to all the data in the database server management system. The transaction server manages all applications in the system, as well as the resources related to the application.

The application on the server can access the database directly, but more often request the scheduling service of CICS, run under the management and coordination of CICS, and access the database. Because CICS centrally manages all the resources related to the application system, including the database, it can run in an optimal way to ensure the optimal overall performance.

With the support of CICS client software, the client application program communicates with the CICS server and requests to run the application program on the server. This relationship can be compared to the stored procedure in the database server and can be called by the client application program. The job of the client application is generally to collect user data, make requests and receive the results answered by the server, which are displayed on the screen.

Business management

The services that the CICS server can provide are determined by the business programs defined in it. As two independent business systems, accounting system and marketing system can be defined either on two CICS servers or on the same CICS server.

In the transaction processing system supported by the CICS server, every business or processing is realized by a reentrant module on the server side. After the module is compiled successfully, the system administrator or developer must add the corresponding definition item to the program definition (PD) in the CICS server and specify the external name of the program. This name is used by client applications to request server-side services. Different business programs are assigned different external names by the system administrator, which will lead to incorrect results if the referenced program name is incorrect.

Load balancing

The load balancing of the CICS service system is realized by the load balancing management driver in the CICS client software, which has nothing to do with the configuration of the background server. CICS client program client connects with one or more CICS servers, monitors the response time of each server, the number of requests processed and other performance parameters, selects the most idle CICS server, and dynamically sends customer requests to the server. The specific load balancing selection algorithm is implemented by the external exit program of the CICS client communication process, which has nothing to do with the application used by the end customer, so there is no need to modify the client application when the load balancing algorithm is changed.

On the CICS client, each CICS server is assigned a name by the system administrator, under which the IP address of the machine on which the CICS server resides and the port number that accepts customer requests (the default port number is 1435. CICS servers that support a large number of concurrent users are usually configured with multiple port numbers to accept customer requests at the same time, and each port number is defined on the client as a CICS server. Even if they belong to the same CICS server). Multiple CICS servers defined by the client join a service group. When the client application issues an ECI call request, the CICS client support software can dynamically select one of the same group of CICS servers, and the selected algorithm can simply cycle the algorithm, or check the algorithm proportionally or dynamically.

The load balancing design of CICS gives the CICS client application the function of dynamically selecting the server. The structure is flexible and simple, and the failure of the access server responsible for load balancing will not affect the operation of the whole system. The setting of the CICS server is relatively independent of that of the client. The CICS client can choose to use load balancer or not; it can also choose whether to do load balancing among all available servers or some available servers; and even choose whether to do load balancing for each program, the scope of load balancing, load balancing algorithm, and so on. With the support of CICS load balancing structure, system administrators can configure multiple CICS servers in a system that undertakes large processing, load exactly the same business programs, and share the system load.

Introduction of communication middleware MQSeries technology:

MQSeries is a communication middleware, which is specially responsible for transmitting data between various platforms, which can ensure that the data will not be lost or repeated when it is transmitted on unstable data lines. Its simple programming interface can greatly simplify the workload of system developers and improve the quality of development.

MQSeries can run not only on the AIX of RS/6000, but also on various platforms such as WindowsNT, UNIX operating systems and even special systems, so that the applications on each platform can exchange data smoothly.

With the promotion and use of MQSeries in the people's Bank of China, it is becoming the de facto standard for transactions in China's financial system. More and more banks and securities systems are interconnected with MQSeries. MQSeries system is a message queuing product and a middleware product used by IBM for communication. It provides a flexible, fast and easy-to-use solution for program-to-program communication in a distributed environment.

MQSeries provides a special mechanism for applications to communicate across the network. The applications involved in communication do not need to establish private and special logical connections. They only need to assemble the data into a message and put it into the message queue. The receiver takes the message from the message queue to achieve the purpose of communication.

M in MQSeries refers to MESSAGE, Q refers to QUEUE, Series means that the product supports almost all platforms, including all the mainstream platforms in the computer industry, and applications running on various UNIX platforms and NT platforms can communicate with each other using the same API.

A system that uses MQSeries to transmit data has the following advantages in system design and application development:

1. Automatic recovery of breakpoint

The MQSeries feature ensures that data is reliably restored from the breakpoint after the network is interrupted and restored, without the programmer considering the network characteristics.

2. Ensure that each piece of data will not be lost or repeated.

Due to the use of advanced programming ideas, MQSeries messages are temporarily stored in stable disk devices until they are fully transmitted.

MQSeries is the only intermediary software that can guarantee one-time transmission of information. In the current situation that the conditions of data transmission lines are generally poor, this is very important for systems that require a high degree of data integrity.

3. Co-existence of multiple protocols

The programming interface provided by MQSeries to developers has nothing to do with specific network protocols, different types of transport protocols at the bottom of the network are transparent to application development, and the communication between applications based on different protocols has become a reality on MQSeries. Compared with the gateway technology, it has unparalleled advantages and can greatly save the development workload of application developers.

4. Asynchronous parallel processing

MQSeries not only supports traditional synchronous real-time response inter-program communication, but also supports asynchronous and parallel working mode. When an application uses MQPUT to send a message to another application, it does not need to wait for an answer from another application, or even care whether the message is received by the other application, and continues to execute the instructions after MQPUT.

5. Real-time response, high-speed transmission

MQSeries provides a communication way to maintain links, so that the transmission of each message does not need to re-establish a new communication link, ensuring the efficiency of real-time response.

MQSeries provides the function of group transmission of large-capacity messages, which is especially suitable for the application of batch transmission of bill data and billing data in billing system.

6. Coexistence of multiple platforms

MQSeries provides a unified programming interface on 23 operating systems, and programs between different platforms can be migrated simply by recompiling.

7. Improve the efficiency of system development

MQSeries is very simple and easy to learn. Users only need to use nine easy-to-use and powerful function calls of MQSeries to complete all communication operations.

MQSeries provides the same C language API on all platforms. Developers who are familiar with the C language environment can write a variety of complex applications at the fastest speed to achieve special functions, including transmitting billing and bill data, meeting the requirements of real-time query in the business, and so on.

Because of the simplicity of MQSeries, it will not restrict the application scope of the program. How to deal with the bill data and control business flow from the program-controlled switch has nothing to do with MQSeries itself, but it can be realized with the support of MQSeries.

MQSeries can not only recover breakpoints automatically, but also forward a large amount of data to the destination in real time or in batches. Then trigger the application to process the information. MQSeries ensures that the information is not lost and not retransmitted.

By using MQSeries to form the communication basis of the billing system, it can effectively ensure the reliability of the whole network and the high-speed and real-time transmission of information, so that the development of the application can focus on the design and implementation of the business.

8. Security guarantee of MQSeries

The billing system is distributed all over the province, and the public data network is used to connect all levels of centers and exchange offices, so the data is vulnerable to attack and interception, so it is necessary to adopt reliable security mechanisms to protect the transmission of confidential data.

MQSeries has powerful security control means to protect the security of data transmission over public data lines. The most suitable means to be used in a distributed environment are security exit programs, message exit programs and sending and receiving exit programs attached to the MCA.

The security exit programs attached to MCA are functional modules that enhance the function of the channel. For example, in the security exit program, when the channel is established, the MCA at both ends of the channel calls the respective security exit program, and the system developers add the function of password confirmation to the security exit program, and the channel can be established only after the two sides of the communication exchange keys successfully.

The security exit program can return the security key. When MCA sends the message through the channel, it calls the message exit program and encrypts the message with the key. After receiving the message, the receiver MCA also calls the message exit program to decrypt the message.

MQSeries's open interface supports a variety of user-developed encryption systems to protect data transmitted over public data networks.

If you want to further achieve stronger security control on the Internet, MQSeries can take advantage of the authentication and encryption services provided by the industry standard DCE (distributed Computing Environment).

This is the end of the introduction of CICS and MQ middleware. Thank you for your reading. If you want to know more about the industry, you can follow the website, the editor will output more high-quality practical articles for you!

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