JPH08115244A - Distributed transaction processing system and transaction control system - Google Patents

Abstract

PURPOSE: To improve the performance of transaction control in a distributed transaction processing system. CONSTITUTION: In this distributed transaction processing system 110, a message reception optimization part 109 is provided, and when a transaction branch 103 receives a message for the transaction control, the message reception optimization part 109 is provided with a means for generating and transmitting the message which is the same kind as the message to the transaction branch belonging to the same transaction present in a computer where the transaction branch 103 is present. Further, by providing the means and providing information for indicating the computer where the transaction branch which is the ancestor of the transaction branch is present for the respective transaction branches, a message transmission optimization part 108 is provided and the message transmission optimization part 108 is provided with the means for controlling the message to a slave branch present in a computer name recorded in the information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distributed transaction processing system in which, in a distributed system in which a plurality of computers are connected by a communication network, the plurality of computers cooperatively perform transaction processing.

[0002]

Transactions are a concept introduced by many data processing systems. A transaction is a processing sequence defined by an application program (AP). The data processing system performs exclusive control of data, failure recovery, and the like with a transaction as a management unit. Such a data processing system is called a transaction management system. In a transaction management system, multiple transactions are processed in parallel. Further, the transaction management system records and manages information on the above-mentioned plurality of transactions. Distributed transaction processing in a distributed system in which a plurality of computers are connected by a communication network and messages are transmitted and received between the computers through the communication network, and a distributed system in which each computer has a transaction management system Called the system.

FIG. 2 is a diagram for explaining a transaction in the distributed transaction processing system. In the distributed transaction processing system, one transaction 201 is distributed to and processed by a plurality of computers 202. Such a tree structure in which one transaction is distributed is called a transaction tree 203, and each of the distributed portions of the transaction in each computer is referred to as a transaction branch 2
Call 04. A transaction branch that is the head of a transaction started by a certain AP is called a root branch 205. In addition, the transaction branch to which a certain transaction branch has branched is called a child branch, and the branch source transaction branch is
It is called the parent branch of the transaction branch. In addition, the transaction is distributed from the root branch, and all transaction branches that are parent branches of the branch source until reaching a certain transaction branch are
Called the ancestor's transaction branch. Moreover, although the transaction branches are distributed to a plurality of computers, it is quite possible that a plurality of transaction branches belonging to the same transaction exist in the same computer.

As shown in FIG. 2, for a transaction distributed to a plurality of computers, the entire transaction can be validated if all distributed transaction branches are successfully processed. Also, if any one transaction branch fails, the entire transaction must be invalidated and all transaction branches failed, even if the other transaction branches succeed. A processing method for performing such control is called a transaction control method. For the transaction control method used conventionally, see Mo
han, et al: ”Efficiant Commit Protocols for the T
ree of Processes Model of Distributed Transactio
n, “ACM Proceedings of the 2nd SIGACT / SIGOPS Symp
osium on Principles of Distributed Computing, pp.
76-88, 1983.

The transaction control method used in the above-mentioned known example is called two-phase commit (2PC).
This 2PC will be described below.

When the AP requests a commit, the root branch sends a commit prepare request message to the child branches along the transaction tree. The transaction branch that has received the commit preparation request message further sends a commit preparation request message to its own child branch, and a transaction branch having no child branch has its own processing ready for commit to the parent branch. Returns a response message as to whether or not it has been done. The branch receiving the response message from the child branch returns a response message indicating whether or not its own processing is ready for committing together with the response message from the child branch to the parent branch. Similarly, when the response message is returned to the parent branch in sequence, the response message is finally returned to the root branch.

The response message received by the root branch reflects the response message indicating that all transaction branches of this transaction are ready for commit. Therefore, if all transaction branches are ready for commit, the root branch receives It decides to commit the entire transaction, sends a commit request message, and sends commit request messages to child branches in sequence, similar to the commit prepare request message above. In addition, if the root branch returns a response message that there is a transaction branch that could not be completed in the response message of the commit preparation completion, it decides to abort this entire transaction and sends an abort request message, Like the commit preparation request message, the abort request message is transmitted to the child branch. When receiving the response message to the commit (or abort) request message, the root branch ends the process for this transaction.

[0008]

First, the first problem will be described. In 2PC in the distributed transaction processing system, one request message indicating a certain process is sequentially transmitted from the root branch to the child branch along the transaction tree, and from the child branch to the parent branch, a response message to the request message. Is returned and finally arrives at the root branch, the root branch sends a request message indicating the next processing.
Since the child branch cannot start the next processing until the request message from the parent branch is received, the message reception waiting time from the parent branch increases as the number of branches of the transaction branch increases. Therefore, it is an issue to solve the performance deterioration due to such message waiting time.

Next, the second problem will be described. 2P
In C, many messages are transmitted and received across a plurality of computers. However, message transmission between computers has a large overhead, which leads to deterioration of throughput of the distributed transaction processing system as a whole.
Reducing the number of messages across computers is an issue.

[0010]

Means for Solving the Problem First, the means for solving the first problem will be described. The distributed transaction processing system of the present invention exists in a computer when a message for transaction control is received with respect to a transaction branch existing in each computer,
And a means for discriminating a transaction branch belonging to the same transaction as the transaction branch targeted by the message, a means for generating a message of the same type as the message for the transaction branch discriminated by the discrimination means, The transaction branch discriminated by the discriminating means is provided with means for passing the above-generated message.

Next, means for solving the second problem will be described. The distributed transaction processing system of the present invention includes, for each transaction branch, information indicating a computer name in which a transaction branch of an ancestor of the transaction branch exists, and the transaction branch existing in each computer is used for transaction control. When a message is received, a function of discriminating a child branch existing in a computer in which an ancestor transaction branch exists, based on the above information,
Means are provided for determining the need to send a message to the child branch.

[0012]

According to the present invention, by the means for solving the first problem, the transaction management system of each computer exists in the computer when the message for transaction control is received, and the message is targeted. A transaction branch belonging to the same transaction as the transaction branch is discriminated, and a message of the same type as the message is generated and transmitted to the discriminated transaction branch. As a result, the message can be transmitted to all the transaction branches at an early stage, and the performance deterioration due to the message waiting time can be prevented.

With respect to the second problem, when a transaction branch existing in a computer receives a message for transaction control from the means for solving the first problem, the same transaction in the computer including the transaction branch is received. The same kind of message as the above message is also transmitted to the transaction branch belonging to. Therefore, even in a computer having a transaction branch that is an ancestor of the transaction branch that has received the message, the transaction branch belonging to the transaction has already received the message. As a result, the transaction branch that received the message refers to the information recorded in the computer in which the transaction branch of the ancestor exists when transmitting the message to the child branch, so that the transaction of the ancestor recorded in the information is referred to. The message is not transmitted to the child branch existing in the computer in which the branch exists. As a result, the number of messages spanning computers can be reduced.

[0014]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of the distributed transaction processing system. In the distributed transaction processing system 110, a plurality of computers 100 having a transaction management system 102 are connected by a communication network 101. In the transaction management system 102, a plurality of transaction branches 103 are processed in parallel. The transaction table 106 records various information regarding transaction branches existing in the transaction management system 102. In this transaction table 106, sufficient information for discriminating whether or not there is a transaction branch belonging to the same transaction in the computer is recorded. The transaction control function unit 107 controls 2PC of a plurality of transactions.
The communication function unit 105 also controls communication between a plurality of computers.

First, an embodiment of a method for solving the first problem, that is, the performance deterioration due to the message waiting time will be described. In order to realize the present invention, the message reception optimization unit 109 shown in FIG. 1 is provided. When the transaction branch receives the message, the message reception optimizing unit 109 determines whether or not there is a transaction branch belonging to the same transaction in the computer.
It is determined by referring to the transaction table 106, a message of the same type as the message is generated, and the message is transmitted to the determined transaction branch.

FIG. 3 shows a part of the transaction distributed to the plurality of computers in FIG.
It shows how messages are transmitted in sequence from to child branch. The computer A300 has a transaction branch a312 and a transaction branch b314 that belong to the same transaction. Message A320, Message B322, Message C3
24, the message D326, the message E328, the message F330, and the message G332 are all the same type of message.

FIG. 5 shows a processing flow of a method for solving the first problem of the present invention. The processing flow of FIG. 5 will be described with reference to FIG. For example, in step 500, transaction branch a312 receives message A320. In step 502, the message reception optimizing unit 109 discriminates the transaction branch b 314 belonging to the same transaction as the transaction branch from the transaction table 106. In step 506, the message reception optimization unit 109
The message D326 of the same type as the message A320 is generated in the determined transaction branch b314, and the message D326 is transmitted to the transaction branch b314. In step 508, the transaction branch a 312 and the transaction branch b 314, which have received the message 320A and the message D 326, respectively, are transferred to the respective child branches to the communication function unit 1.
A message of the same type as the above message is transmitted via 05. For child branches of transaction branch a312, message B322 and message C3
24 is transmitted, and the message G332 is transmitted to the child branch of the transaction branch b314.

In another example, when the transaction branch C316 existing in the computer C304 receives the message B322 in step 500, the message transmission optimizing unit 108 searches the transaction table 106 in step 502, and in step 504. , A transaction branch belonging to the same transaction as the transaction branch existing in the computer C304 is determined. As a result of the determination, there is no corresponding transaction branch, so step 5
At 08, the message E328 is transmitted to the transaction branch d318 which is a child branch of the transaction branch c316.

Next, an embodiment of a method for reducing the number of messages across computers, which is the second problem, will be described. This method is effective after carrying out the means for solving the first problem of the present invention.

In order to implement the present invention, each transaction branch is provided with information indicating the computer name in which the transaction branch of the ancestor of the transaction branch exists. This information is used as the route information 104.
Call.

Further, the message transmission optimizing unit 108 shown in FIG. 1 is provided, and the message transmission optimizing unit 108 is
When a transaction branch sends a message to a child branch, it is determined whether the same computer name as the computer having the child branch to which the message is sent is included in the route information 104. Does not send the message to the child branch existing in the computer.

FIG. 4 shows a part of a transaction distributed to a plurality of computers as in FIG. 3, but shows how messages are sequentially transmitted from the root branch 310 to child branches. The computer A300 has a transaction branch a3 belonging to the same transaction.
12 and transaction branch b314 exist. Message A320, Message B322, Message C324, Message D326, Message E328,
The message F330 and the message G332 are all the same type of message.

A method of recording the route information will be described using the route information B402. The transaction from the root branch 310 is transaction branch a312
To the transaction branch c316. At this time, the branch source computer is computer B,
Since it is the computer A, that is, the ancestor transaction branch exists in these computers, "B, A" is recorded in the route information B402.

FIG. 6 shows a processing flow of a method for solving the second problem of the present invention. The processing flow of FIG. 6 will be described with reference to FIG. For example, in step 600, computer A
It is assumed that the transaction branch a312 existing in 300 receives the message A320. Step 602
Then, the message transmission optimization unit 108 determines that the route information 40
In 0, it is determined whether or not the computer name in which the child branch of the transaction branch a312 exists is recorded. The child branch of the transaction branch a312 exists in the computer C304 and the computer E308, but the computer name recorded in the path information 400 is the computer B302.
Since it is only, it does not coincide with step 602. Therefore, in step 606, the transaction branch a
A message B3 312 is sent via the communication function unit 105.
22, message C324 is transmitted.

In the present invention, in the embodiment of the means for solving the first problem, in the distributed transaction processing system,
When the message reception optimization unit 109 is provided and the transaction branch a 312 receives the message A 320,
The message reception optimizing unit 109 searches the transaction table 106 to determine a transaction branch b314 that belongs to the same transaction as the transaction branch a312 and sends the message 320 to the transaction branch b314.
The same type of message 326 is generated and transmitted.

Next, as another example of the processing flow of FIG. 6, a case where the transaction branch c316 receives the transaction will be described. In step 600, computer C3
The transaction branch c316 existing in 04 receives the message B322. In step 602, the message transmission optimizing unit 108 determines whether or not the computer name of the child branch of the transaction branch c316 is recorded in the route information 402. The transaction branches belonging to the same transaction existing in the computer recorded in the route information have already received the same type of message by the solution method of the first problem. Can determine which transaction branch is receiving The child branch of the transaction branch c316 exists in the computer D306 and the computer A300, and the names of the computer B and the computer A are recorded in the route information 402. Therefore, in step 604, it is recorded in the route information 402. Calculator A with a child branch
Message is already transmitted to the transaction branch b, which is a child branch existing in the computer A.
The message F330 is not transmitted to 314. Also,
Since the computer D306 is not recorded in the route information 402, it is a child branch of the transaction branch c316, and sends the message E328 to the transaction branch d318 existing in the computer D306 via the communication function unit 106.

[0028]

According to the present invention, in order to solve the first problem, in the distributed transaction processing system, 2PC
Thus, the message waiting time of distributed transactions can be reduced and the transaction processing performance can be improved.

With respect to the second problem, it is possible to reduce the number of times messages are transmitted and received among a plurality of computers, and it is possible to improve the throughput of the entire system.

[Brief description of drawings]

FIG. 1 shows a system configuration of a distributed transaction processing system to which the present invention is applied.

FIG. 2 shows a description of transactions in a distributed transaction processing system.

FIG. 3 shows a method for early transmission of a message in the first embodiment of the present invention.

FIG. 4 shows a method for reducing the number of messages using route information according to the second embodiment of the present invention.

FIG. 5 shows a processing flow in the first embodiment of the present invention.

FIG. 6 shows a processing flow in a second embodiment of the present invention.

[Explanation of symbols]

102 ... Transaction management system, 103 ... Transaction branch, 104 ... Path information, 105 ...
Communication function unit, 106 ... Transaction table, 1
07 ... Transaction control function unit, 108 ... Message transmission optimization unit, 109 ... Message reception optimization unit,
110 ... Distributed transaction processing system.

Claims (4)

[Claims] 1. A distributed transaction processing system in which a plurality of computers are connected by a communication network and each computer processes a transaction, and one transaction is divided into a plurality of transaction branches for processing. A distributed transaction processing system, in which individual transaction branches are created by branching from other transaction branches, and a parent-child relationship exists between those transaction branches, and the transaction branch Is a distributed transaction processing system in which each transaction branch is processed by an individual computer. When a transaction branch receives a transaction control message, the transaction branch A transaction branch that exists in the computer in which the message exists and that belongs to the same transaction as the transaction branch targeted by the message, and the transaction branch determined by the determining means has the same type as the message. A distributed transaction processing system, comprising: a means for generating the message and a means for passing the generated message to the transaction branch discriminated by the discrimination means. 2. The distributed transaction processing system according to claim 1, further comprising, for each transaction branch, information indicating a computer in which a transaction branch of an ancestor of the transaction branch exists.
With respect to a certain transaction branch, the individual computer refers to the above information when a transaction control message from the parent transaction branch is received, and means for determining a child transaction branch existing in the computer in which the ancestor transaction branch exists. , A distributed transaction processing system comprising means for determining the necessity of message transmission to the child transaction branch. 3. A distributed transaction processing system in which a plurality of computers are connected by a communication network and each computer processes a transaction, and one transaction is divided into a plurality of transaction branches for processing. A distributed transaction processing system, in which individual transaction branches are created by branching from other transaction branches, and a parent-child relationship exists between those transaction branches, and the transaction branch However, in a distributed transaction processing system in which each transaction branch is processed by an individual computer, when a transaction branch receives a transaction control message, the transaction branch Exists in the computer in which exists, and determines a transaction branch that belongs to the same transaction as the transaction branch targeted by the message, and for the transaction branch determined from the above, generates a message of the same type as the message, In the transaction branch determined from the above,
A transaction control method for passing the message generated above. 4. The transaction control method according to claim 3, comprising, for each transaction branch, information indicating a computer in which a transaction branch that is an ancestor of the transaction branch exists, and each transaction branch is provided in each computer. When the transaction control message from the parent transaction branch is received, it is necessary to refer to the above information, determine the child transaction branch existing in the computer in which the ancestor transaction branch exists, and send the message to the child transaction branch. A transaction control method that determines the sex.