KR0146998B1 - Method of message forming & sending in a distributed realtime dbms - Google Patents

Abstract

An object of the present invention is to provide a method for constructing and delivering a message regardless of an IPC transmission unit by a block in a DBMS that processes a user's query request in an ATM switch which is a distributed real-time system. In order to achieve the above object, the present invention provides a number field, a number field of a message, a number field of information in a message, a location field of each information, and a size of each information within a fixed size in IPC transmission units. The message organizer to include a field and a content field of each information, the first step is to store the number of messages to be delivered, determine the information to be included in the message, store the number and prepare the first information, and then start the information. A second step of storing the location and the size thereof; a third step of storing the data if the size of the prepared information is smaller than the remaining storage space in the message; If the size is larger than the remaining storage space in the message, only the amount of storage space is stored in the message and a new message is created. The fourth step of storing the number of the message additionally allocated to the storage space, and after storing all the information, the total number of prepared messages is stored in the first field of the message, and finally the prepared messages are stored in the receiving block. And a fifth step of transmitting in sequence.

Description

Method of message organization and delivery in distributed real-time database management system (DBMS).

1 is a structural diagram of a main memory DBMS having a distributed structure of an ATM switch system;

2 is a structural diagram showing a configuration and a message flow between blocks of an ATM switch system DBMS;

3 is a structural diagram showing the composition of a message when there is only one message;

4 is a structural diagram showing the composition of each message when there are two or more messages;

5 is a flow chart of the process of constructing and sending a message in a block for delivering a message in a DBMS.

The present invention relates to a message construction and delivery method in a database management system (DBMS) of a distributed real-time processing communication system.

In the conventional exchange DBMS (Database Management System), each block constituting the DBMS shares its role in supporting data manipulation of applications that perform call processing, operation, maintenance, billing, and statistics functions. Perform. Each block communicates with each other by passing messages as signal parameters.

The size of the message, which is a parameter of the signal, should be less than or equal to the transmission unit of IPC (Inter Processor Communication). If the size of the information conveyed in the message is each fixed, the data structure of the message is defined as one fixed structure that contains all of the information. Each fixed size of information defines the message by dividing the size of every single message data structure into more than one IPC transport unit and then subdividing it into several data structures below that transport unit. On the other hand, if the size of information values to be transmitted is variable, the size of each information is fixed to a defined maximum size to compose a message in the same manner as described above. However, if one information value is larger than the IPC transmission unit, it cannot be accommodated in one message, causing an error.

For example, if your request includes both verification and change clauses and modifies the database of the remote processor, the DBSG's Database Supporting Group (DBSG) is the DBSG of the remote processor. Fields, conditional clauses, modified clauses, and data structures of the required relational tuples. The various information related to the command is fixed in size. However, conditional clauses and change clauses vary in size depending on the instructions in the application. In addition, the data structure of the tuple in the relation also has a variable size depending on the relation. Currently, the maximum size of a data structure with these three variable size values is defined in units of IPC transmission. Therefore, the DBMS delivers a message for information related to a command, a message for a condition clause, a message for a change clause, and a message for a release tuple data structure.

However, in most cases, the size of the content to be delivered with the variable structure is much smaller than its maximum size, so the DBMS wastes considerable execution time for communication between blocks. If the sum of the actual contents of all the information does not exceed the IPC transmission unit, it can communicate in one message transmission including all the information. However, in the current DBMS, since each variable information is fixed to the maximum size, a message is transmitted four times. As a result, the delay time for communication between blocks has a significant impact on the execution time delay of the entire DBMS.

In addition, since all messages are defined not to exceed the IPC transmission unit, they have a close relationship with the system and the operating systems (OS). Therefore, current DBMSs are not compatible with systems with different IPC transmission units. In other words, the exchange system with smaller IPC transmission unit size should reexamine the information contained in all messages and modify the message size so that it does not exceed the IPC transmission unit. In exchange system with larger IPC transmission unit, do not redefine the message. If not, the DBMS will have to pay much less than the communication capabilities provided by the system.

Therefore, there is an urgent need for a message delivery method in a DBMS that can cope with variable IPC transmission units depending on the system.

Accordingly, the present invention devised to solve the problems of the prior art, a method in which each block in the DBMS that processes a user's query request in the ATM switch, which is a distributed real-time system, constructs and delivers a message regardless of IPC transmission units The purpose is to provide.

In order to achieve the above object, the present invention provides a number field of all messages, a number field of a corresponding message, a number field of information in a message, a location field of each information, and each information within a fixed size in IPC transmission units. A first step of composing a message to have a size field of, and a content field of each information; storing the number of delivered messages, determining the information to be included in the message, storing the number, and preparing the first information. A second step of storing the start position and the size of the step; and a third step of storing the data if the size of the prepared information is smaller than the remaining storage space in the message, and preparing the information if the next information to be stored further exists. If the size of the information to be stored is larger than the remaining storage space in the message, only the amount of storage space is stored in the message, A fourth step of storing an additional number of storage space for the message, and storing all the information, and storing the total number of prepared messages in the first field of all messages, and finally preparing the prepared messages. And a fifth step of sequentially transmitting to the receiving block.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

1 is a structural diagram of a main memory DBMS having a distributed structure of an ATM switch system to which the present invention is applied.

The ATM switch to which the present invention is applied has two subsystems: an ATM Central Switching Subsystem (ACS) 1 and an ATM Local Swtching Subsystem (ALS) 2. The ACS 1 performs a function of operating, maintaining, and managing a system, and maintaining various traffic information, statistics, and billing information, and is equipped with an operation and maintenance processor (OMP) 3. The ALS 2 is a processor that performs access processing of a general subscriber, performs access control according to a subscriber service request together with a subscriber matching circuit, and performs a traffic control function such as access admission control and congestion control. The ALS 2 is installed in large numbers depending on the subscriber and has a subscriber call processor (SCP) 4.

CSW (Central Switch) 5 is responsible for the switch for each ASW (Access Switch) 6, ASW (6) is responsible for the subscriber switch in the ALS (2), OMP (3) is CSW (5) The SCP (4) is connected to one port of the port and the SCP (4) is connected to one port of the ASW (6) via the Inter Module Interface (IMI) link to send and receive messages. Communication between SCPs is a three-stage structure of ASW-CSW-ASW and communication between OMP and SCP is a two-stage structure of CSW-ASW.

ATM DBMS is distributed to each processor to manage data distributed to multiple processors, resides in main memory for real time processing, retrieves and modifies data, remote data processing, duplicate data processing, data backup It provides features, data recovery, concurrency control, and transaction management.

Among the above processors, the DBMS of OMP (3) is divided into five blocks: Database Kernel Group (DBKG), Database Backup Group (DBBG), Database Supporting Group (DBSG), Database Transaction Group (DBTG), and Database Query Group (DBQG). The DBMS of SCP (4) is provided with three blocks: DBKG, DBSG and DBTG. The only difference between OMP and SCP is that it is equipped with a disk and performs the function of receiving input from the operator. Therefore, only OMP has a DBBG block for accessing the disk and a DBQG block for interfacing the operator terminal with the ATM switch system.

Each block in the DBMS is responsible for receiving the request to manipulate the data from requests entered directly from the application or the user and returning the results. The DBKG is responsible for retrieving and changing data in the database, concurrency control, and log generation function according to the retrieval and change of data that the processing request comes in. The DBSG performs the functions of requesting DBKG to handle retrieval and change requests for remote data within the application and the communication function between DBMSs of other processors for remote data processing. If necessary, it is responsible for backing up the database on disk and restoring the database on system restart. DBTG performs transaction management functions, and DBQG performs on-line interactive query processing functions that occur on an operator terminal or PC.

2 is a structural diagram showing the flow and configuration of messages between related blocks for sending and receiving messages implemented on an ATM exchange system, which is a distributed real-time system.

In OMP (3), the DBSG commands the DBKG to work through a procedure call. Therefore, there is no message passing between DBSG and DBKG. DBSG acts as an interface between DBKG and other blocks, exchanging messages through all other blocks and signals except DBKG in OMP. In addition, DBTG and DBBG exchange messages with each other for data backup and recovery during transaction processing. In SCP (4), there is a message transfer between DSBG and DBTG as in OMP. In order to perform a query request for a remote relation existing in another processor, communication between DBs is performed between each processor, that is, between OMP and SCP or SCPs.

3 is a structural diagram of messages exchanged between the blocks constituting the DBMS of the ATM exchange system.

The message construction method proposed by the present invention is to integrate a data structure having one variability regardless of what information the messages exchanged between the building blocks in the DBMS contain.

The size of the message is fixed in IPC transmission units, and the composition fields of the message are the total number of messages, the number of messages, the number of information in the message, the location of each information, the size of each information, and the contents of each information. Since the contents of each piece of information may be variable in size, they can be accessed using the location and size information fields of the information in the message. The sum of the sizes of each field should not exceed the IPC transmission unit.

4 is a structural diagram of messages when the sum of the sizes of each field exceeds the IPC transmission unit.

The size of each message is fixed in IPC transmission units. If all messages are concatenated in order by message number, their structure is almost identical to that in Figure 3. In the second and above messages, only the total number of messages and the number of the message are added.

5 is a flowchart showing a process of performing a task for delivering a message in a block for delivering a message of a DBMS.

First, the number of the message to be delivered is stored (7) and the information to be included in the message is determined and the number is stored (8). After preparing the first information (9), the starting position of the information and its size are stored (10) (11). If the size of the prepared information is smaller than the remaining storage space in the message, data is stored (12). If there is next information to be stored further, prepare (13) and repeat the previous work related to the information. If the size of the information to be stored is larger than the remaining storage space in the message, only the amount of storage space is stored in the message (14), and then additional storage space is allocated for the new message (15). Save (16). Perform the appropriate action by comparing the amount of information left in the new message.

After storing all the information by the above processing procedure, the total number of prepared messages is stored in the first field of all messages (17). Finally, the prepared messages are transmitted to the receiving block in order (18).

In the block for receiving messages transmitted through the process of FIG. 5, the number of messages to be received, which is the first field of the message that arrives first, is seen. After receiving the number of messages, they are ordered by the number of messages and the information is read.

The message structure constructed as described above and its transmission and reception method are applied to a distributed real-time DBMS of an ATM switch, resulting in the following effects.

First, since only actual contents of information having a variable structure are kept in a message, the number of messages to be transmitted can be reduced, resulting in a reduction in execution time corresponding to communication between blocks. As a result, since the communication speed between blocks is supported, it greatly contributes to shortening the execution time of the entire DBMS that requires fast real-time processing speed. Second, even if the size of each message is fixed in IPC transmission units, the composition and storage method of the contents are independent of the IPC transmission units, and thus the IPC transmission units are freely compatible with other systems. Third, when the size of the information is larger than the IPC transmission unit, since it can be divided into several messages having the structure proposed in the present invention, any kind of data can be supported.

Therefore, the DBMS is not only compatible with any system but also the maximum capacity of the IPC transmission unit supported by the system allows the communication speed between each block in the DBMS to be optimized, thus increasing the speed of executing the user's query request. .

Claims (3)

A message construction and delivery method applied to a database management system (DBMS) of a distributed real-time processing communication system, wherein the number of total messages, the number of messages field, and the number of information in a message are within a fixed size in IPC transmission units. A first step in composing a message to have a field, a location field of each information, a size field of each information, and a content field of each information, storing the number of the delivered message and determining the information to be included in the message. After storing the number and preparing the first information, the second step of storing the starting position and the size of the information, and if the size of the prepared information is smaller than the remaining storage space in the message, then the data that needs to be stored and stored further The third step of preparing the information if it exists, and the size of the information to be stored is greater than the remaining storage space in the message. In this case, the fourth step of storing only the size of the storage space in the message and then allocating the storage space for a new message and storing the number of the message, and the total number of prepared messages after storing all the information And a fifth step of storing in the first field of every message and finally sending the finally prepared messages to the receiving block. The method of claim 1, wherein the first step is configured such that the sum of the sizes of each field does not exceed an IPC transmission unit. 3. The method of claim 2, wherein the first step includes maintaining only the number of total messages and number information of the corresponding message in the second or more messages. .