KR0146657B1 - Control method of server process for client/server computing - Google Patents

Abstract

The present invention relates to a method of operating a system in a client / server technology that classifies a system owned by a user into a client class and a server class, and connects each system, and includes a database access function, a query processing function, and a report processing function. A client / server application processor generation CASE tool comprising a function, an editing function, a client / server function, and an object management function. The server having the CASE tool has a number of users who want to access a database. When the server keeps operating to control this support, if any client attempts to connect, it connects with the client, receives the commands required by the client as a data packet, decrypts them, processes them appropriately, and packetizes the result. Service to send to the above client To be the first; and a second process that maintains until it disconnects from the client is connected.

Description

A control method of server process for client / server computing

1 is a diagram illustrating a general configuration method of a client / server system.

2 is a diagram illustrating a method of configuring a client / server tool according to the present invention.

3 is a diagram showing the overall flow of the server processor according to the present invention.

The present invention relates to a method for operating a client / server system, and more particularly to a method for controlling a server processor in a client / server system for emphasizing user convenience.

In general, the computer system structure, which plays a key role in the information and telecommunications field, is now being transformed into its own open system, the hardware price is falling, the performance and communication network technology are being advanced, and the application range is also improved. With the trend of downsizing, it is spreading to various applications based on the client / server model as well as the conventional online transaction processing field.

The client / server technology is a new technology in terms of system configuration that will emerge with the development of communication network technology and the appearance of client-class computers such as personal computers and workstations. The concept has been applied to telecommunication-related fields and has been attracting attention in Korea for several years.

It is also one of the key technologies in distributed system software that includes transaction processing and management features based on the client / server model, access to heterogeneous databases, and a graphical user interface that emphasizes ease of use.

As shown in the attached FIG. 1, the configuration of the system to which the client / server technology is applied must be combined with the technology of classifying the system owned by the user into the client class and the server class and connecting them. It is designed to be configured.

The client / server technology configured as described above is an open software structure that complies with the standard, and provides a remote service in a transparent manner to users connected to different resources (computer software) through a communication network.

A representative example of the above technique is a system configuration technique in which an application program or a user interface is downsized and uploaded to a client-class computer.

Examples of following this model vary depending on the scope and purpose of the application, such as database servers, communication servers, print servers, file servers, security servers, and authentication servers. Among them, representative servers that are closely related to distributed processing are database servers. to be.

However, in order to build a client / server model as compared to the conventional time-sharing model, an additional developer burden increases.

In other words, the developer has to acquire communication network programming technology and graphic user interface technologies that are much more complicated than the existing programs, and interoperability problems are always required to operate without any additional work in systems having various specifications. Therefore, a problem that emerges as an important issue in client / server system construction occurs.

An object of the present invention for solving the above problems is a client / server system for enabling mutual compatibility between systems having a variety of specifications without the skill acquisition of developers, which is inevitably increased in order to build a conventional client / server model Provides a server processor control method.

Client / server application processor generation CASE tool according to the present invention for achieving the above object, first, to name or change the name of the host computer system on the server, to view, name, change and A database connection function that cancels and handles the login required to use the database. Second, provides schema information of the specified database, processes the query using menus or windows, and executes the query through the edit query window. Query processing function to edit, check consistency of query statement, and third, system-provided basic report or user-defined report that user extracts data extracted by query processing function. Report processing function to be able to make, and the fourth is both form editing function The expression is one or several screens created by the CASE tool of the present invention, and one form has an editing function for having multiple unit object functions and editing functions for objects in the form, and fifth, input / output (Export / Import). It is a function to send and receive data to and from spreadsheets and graphic tools provided in personal computers or workstations. The client and server functions of OLE (Object Linking Embedding) and DDE (Dynamic Data Exchange), In order to maintain and manage individual objects and other necessary information used in the CASE tool of the present invention, the object management function is to perform the object management function that enables the user to easily and quickly use the functions related to storing and extracting the input and output of objects. have.

The operation method using the client / server application processor generation CASE tool of the present invention having such characteristics is a system operation method in client / server technology that classifies a system owned by a user into a client class and a server class and connects each system. Is a 4th generation computer aided software that creates client / server application programs using multimedia in a distributed processing environment, and acts as an information window in each of client and server systems. 'Hanmad Server' continues to allow the server to support and control the first process of providing the 'Hanmad Server' when multiple users using multiple clients attempt to access the database through 'Hanmad'. Open and open from any client After attempting to connect with the client, it receives and decodes the commands requested by the client as a data packet, processes the commands appropriately, and packetizes the result and sends the result to the client until the connected client disconnects. The note includes a second process.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 2 shows how to configure Hanmadang, a client / server tool. Briefly explaining 'Hanmadang' in the illustrated configuration, 4GL (4th Generation) for generating a client / server type application program using multimedia in a distributed processing environment. As a CASE (Computer Aided Software Engineering) tool in the form of a language, the 'Hardyard' in the client part can access the database through the 'Hardyard Server' in the server part through the communication network. In the following description, 'hanmadang' means a client / server application program generated CASE tool according to the present invention.

Client / server application program generation CASE tool according to the present invention, that is, 'Hanmadang', has the following features.

An important feature of the present invention is the addition of multi-media and hypertext processing to the database forward processor function that can access the database system on the server. This 'Hanmadang' has essential functions such as the creation of various forms in the server, multimedia support function, multimedia form function, multimedia support function, script function, sequential expression function, etc. In addition to these features, it has optional features such as access to the OSF / DCE (Open Software Foundation / Distributed Computing Environment), which is a basic distributed processing environment, and the use of a distributed database management system.

There are six essential components for each function of the CASE tool 'Hanmadang' according to the present invention. The first is a database access function that names or changes the host computer system on the server, retrieves the name of the database on the server, assigns, changes and cancels the logins, and handles the logins required to use the database. . The second is to provide the schema information of the designated database, to process the query using menu or window, to edit the query through the query edit window, and to check the consistency of the query. Function. The third is a report processing function that allows you to create a basic report provided by the system for the data extracted by the query processing function or a user-defined report edited in a desired format. Fourth, the form editing function is a form that is easily described so that one or more screens are created in one yard. A form must have multiple unit object functions and editing capabilities for the objects in the form. Fifth is the Export / Import function. It is the client and server functions of OLE (Object Linking Embedding) and DDE (Dynamic Data Exchange). The sixth is the object management function that enables to easily and quickly use the functions related to storing and extracting the input and output of objects by maintaining and managing individual objects and other necessary information used in 'Hanyard'.

The environment of 'Hanmadang', the CASE tool of the present invention designed to satisfy the six characteristics described above, is divided into a client part and a server part, as shown in FIG. 2. The operating system is UNIX and a medium computer server part. Its main function is provided by a relational database management system that supports standard SQL, and communicates with clients through TCP-IP communication. This will be extended to DCD-RPC (Distributed Computing Environment-Romote Procedure Call) communication method. On the client side, the user interface uses Windows and the PC-TCP communication method with server-level TICOM on i386 or higher compatible systems using MS-DOS.

As shown in Fig. 2, 'Hanmadang' of the client part can access the database through 'Hanmad Server' of the server part via the communication network. According to the present invention, 'Hanmad Server' continues to operate so that the server can support and control the database when multiple users using multiple clients attempt to access the database through Hanmadang. Receives the commands required by the client as a data packet, decodes them, processes them appropriately, and packetizes the result, and sends the service to the client until the connected client disconnects.

The overall flow of the 'one yard server' processor for performing the above operation will be described in detail with reference to FIG. 3.

In step S1, a daemonization operation is performed so that the process can be operated even if the person who executes the processor logs out of the system. Even though the medium system used as a server in the one-yard server is a V-type operating system, Medium library network libraries are based on BSD sockets.

In addition, since the medium system does not have Inetd, it is necessary to perform daemonization in the processor. In other words, you must use a system library called setpgrp ().

Thereafter, in step S2, the zombie processor is removed using the system library signals SIGCLD and SIGIGN. That is, when one processor is terminated, it is checked whether there is a slave processor that is operating. If there is a slave processor, the processor waits until the slave processor ends and terminates the processor.

Briefly explaining why the above operation is performed, the zombie processor causes the zombie processor to be shut down before the slave processor terminates when the system operation is wrong or the user makes an error. If you don't solve it, you can't service the user beyond the limit.

When the preparation work of step S1 and step S2 is finished, the socket is opened for connection with the client in step S3. The type of socket to be used is determined.

Thereafter, in step S4, a bind operation is performed to map an address to the socket determined in step S3, and in step S5, a listen operation is performed to check queue limits of connectors that will use the socket.

When the above operation is performed, the client is ready to connect with any client, so in step S6, an environment such as a memory used by the 'one mad server' processor itself is initialized, that is, one daemon is initialized.

If a plurality of clients attempt to connect at the same time after the daemon initialization work is finished in step S6, a selection operation for selecting one of them is performed in step S7, and if the operation up to step S7 succeeds, step S8 Proceed.

In step S8, the attempt of a job is permitted to the client selected in step S7. At this time, if an error occurs during the process up to step S8, the connection must be retried.

At this time, since the number of clients is large in the client / server system, even if an arbitrary client is connected, the 'one yard server' processor cannot be monopolized. Therefore, in step S9, the 'one yard server' processor is copied and received through a fork process.

Therefore, each time a client connects, the 'one yard server' processor is called a daemon. If the branching process succeeds in step S9, a main processor and a slave processor are generated.

The main processor yields the socket to the slave processor, closes the socket (S16), and waits for another client to connect (S17).

If the connection request waits, the process proceeds to step S9, where the branching process is performed, thereby replicating one 'one yard server' processor to meet the client's request.

This is repeated each time the client requests a connection.

In addition, the slave processor, which has completed all the above steps S1-S9, receives a data packet sent to the client through the socket (S10) and executes commands such as login, db schema information, and query processing.

This timer checks the time at regular intervals in case the system slows down due to a system error or overload, and notifies the client to wait for the server system if it has not handled the client's request during that time. For sake.

In particular, query processing can take a long time, so it is very useful. After the timer is activated, the instruction is decoded (S12) to perform a process (S13) suitable for the instruction.

'Hanmadang server' processor is composed of almost independent sub-processor per instruction.

While executing this command, the timer checks the duration and if the time limit is exceeded (S14), the timer notifies the client of the situation. In this case, the instruction being executed is stopped, and when the timer related processing is finished, the instruction is continued from the stopped point.

After the processing of the instruction requested by the client in the above-described steps S10-S14, the result should be informed to the client. The packet is created and sent in a format defined by the 'one yard server' processor and the 'one yard' of the client (S15).

At this time, if the length of the packet to be transmitted is too long, it is divided into a certain unit (current 4096 bytes), and after each transmission, the remaining data packets are started after the client response. This mechanism is the same for sending data packets from client to server.

After the transmission of the result data, the 'one yard server' processor waits for another command of the currently connected client, and when the command arrives, the above-described operations of steps S10 to S15 are repeated.

Wait for command and repeat command processing until the client disconnects. When the client disconnects, one of the 'one yard server' slave processors is shut down.

By providing a server processor control method in a client / server system according to the present invention operating as described above, mutual compatibility between systems having various specifications can be achieved without a developer's skill acquisition which is inevitably increased to build a conventional client / server model. It can be effective.

Claims (1)

In the method of operating a system in client / server technology that classifies a system owned by a user into a client class and a server class, and connects each system, the first is to name or change the host computer system in the server, Database access to retrieve and specify the name of the database in the database, assign, change, and cancel the logins required to use the database, and provide schema information for the specified database. The query processing function to edit the query through the query processing window, edit the query window, and check the consistency of the query, and thirdly, the system provides the data extracted by the query processing function. Create a default report or a custom report that you edited to your liking. Report processing function, and fourth, form editing function, the form is one or several screens created by the CASE tool, and one form has several unit object functions and functions for editing objects in the form. Fifth, the function of exchanging data with Sophed sheet and graphic tools provided by personal computer or workstation as an input / output function, and OLE (Object Linking Embedding) and DDE (Dynamic) Data exchange) client and server functions, and sixth, can maintain and manage the individual objects and other necessary information used in the CASE tool to easily and quickly use the functions related to the storage and extraction, the input and output of objects It is a client that uses multimedia in distributed processing environment to perform object management function. A client / server application process generation CASE tool, which is a fourth generation language computer aiding software for generating application / server type application programs, is provided. The first step of installing to perform the role, and the server with the CASE tool, the server to support and control the server when multiple users using multiple clients to access the database through the CASE tool When the server with the tool continues to run, and any client attempts to connect, it connects with the client, receives the commands requested by the client as a data packet, decrypts them, processes the commands appropriately, and packetizes the result to the client. The service that sends the corresponding The second process control method for a server processor in a client / server system comprises a that maintains until it disconnects from the client.