KR100611729B1 - Web service system supporting fault-tolerance on the quality and web srevice method thereof - Google Patents

Abstract

According to the present invention, the web service switching process is performed only when a failure occurs, so that service quality factors including a failure can be supported, so that switching to another service can be supported when the desired service quality is not satisfied. The present invention relates to a web service system supporting a quality-based failure recovery that enables efficient service switching and web service searching in a web service, and a web service method using the same, comprising: a web service registration module in which information of a web service is recorded; A web service registration module for registering information of a web service presented from a client or a service provider into the web service registration module; A web service management module for grouping the client and the same web service according to the content of the registered web service; A main web service setting module for checking a response time of a response message received by transmitting a test message requesting a web service, and determining a main web service of a corresponding group; A quality condition checking module which determines whether the response time satisfies a set quality condition and drives the main web service setting module; A client confirmation module for identifying a corresponding client when a web service request message of a client receiving a web service is received; And a communication module for connecting the web service set in the main web service setting module and the client.

Description

Web service system that supports quality-based failover, and web service method using the same {} Web service system supporting fault-tolerance on the quality and web srevice method

1 is a block diagram illustrating a web service system according to the present invention;

2 is a flowchart sequentially illustrating a web service method according to the present invention;

3 is a block diagram showing a structure for providing a web service;

FIG. 4 is a table describing contents to be performed by respective parts in the structure shown in FIG. 3.

5 is a block diagram showing a mapping relationship between WSDL and UDDI,

6 is a table showing a mapping relationship between WSDL and UDDI for tModel,

7 is a diagram illustrating an element schema for grouping between homogeneous web services in a web service system according to the present invention.

FIG. 8 is a diagram illustrating an element schema of the WSGroup illustrated in FIG. 7.

FIG. 9 is a diagram illustrating an element schema of userInfos illustrated in FIG. 7.

10 is a graph showing the response time when using the web service system according to the present invention.

According to the present invention, the web service switching process is performed only when a failure occurs, so that service quality factors including a failure can be supported, so that switching to another service can be supported when the desired service quality is not satisfied. The present invention relates to a web service system supporting a quality-based failover that enables efficient service switching and web service search in a web service, and a web service method using the same.

The environment in which software is developed and operated is changing as the computing environment changes over time. In particular, the proliferation of networks has made it possible to run software in a distributed computing environment that used to be executed only within a closed and independent environment. Web services are a new technology that enables distributed computing using the existing web environment based on XML technology. A web service can be referred to as a service module that allows a user to be delivered to the Internet from a remote place whenever needed. A user can create a new service or application by connecting different service modules. A web service can also be used by multiple users. Many IT-related organizations and companies are looking to Web services as the underlying infrastructure technology for the future computing environment paradigm and strive to gain leadership.

On the other hand, the Internet environment used by web services has several potential problems. There is also the possibility of errors on the network, but the increasing number of hacking and virus attacks shows that there is a constant cause of failure of the Internet. Therefore, in order to stably run an application using a web service, a method of overcoming a failure of the web service is required. The basic method of overcoming a web service failure is to connect to the same web service as the failed web service. Existing methods for overcoming web service failures require some form of modification on the user side, such as handling failure situations in user applications, and the method of finding the same service for service switching is also dependent on the user. In addition, other factors such as quality factors as well as failures of web services cannot be considered.

On the other hand, the conventional methods for overcoming the failure situation take a method of sending a client request after detecting a server failure to a backup server. In the basic structure of web service, the client side must individually detect the service failure, find a new service, and call back to the service. Another study on failover in Web services extends the SOAP message and provides connectable service information to the client, which also requires an engine to process the extended SOAP message on the client side to use the failover service. Have

As such, existing methods require some form of modification on the client to enable failover. In addition, we do not consider how to overcome the service quality that does not reach the desired level in addition to the service failure situation. Also, for searching the same web service as a backup service, registration, automatic search, and connection for both service providers and users are convenient. It cannot be provided.

Accordingly, the present invention has been made to solve the above problems, and when the service provided to the client is interrupted due to the failure of the web server, the work performed at the client level to overcome the problem can be minimized. Even in this case, the purpose of the present invention is to provide a web service system that supports the quality-based failover and the web service method using the same.

In order to achieve the above object, the present invention,

A web service registration module in which information of a web service is recorded;

A web service registration module for registering information of a web service presented from a client or a service provider into the web service registration module;

A web service management module for grouping the client and the same web service according to the content of the registered web service;

A main web service setting module for checking a response time of a response message received by transmitting a test message requesting a web service, and determining a main web service of a corresponding group;

A quality condition checking module which determines whether the response time satisfies a set quality condition and drives the main web service setting module;

A client confirmation module for identifying a corresponding client when a web service request message of a client receiving a web service is received; And,

A communication module for connecting the web service set in the main web service setting module and the corresponding client;

This is a web service system that supports quality-based failover.

In the web service system according to the present invention,

The web service registration module may further include a grouping module for retrieving the information of the web service listed in the web service listing module and subdividing the grouping of similar web services around the synonym.

In the web service system according to the present invention,

The web service registration module is UDDI;

The web service management module is driven by mapping the UDDI and the WSDL such that a tModel constituting the UDDI is defined as an interface of a WSDL.

In order to achieve the above object, the present invention,

In the web service system supporting quality-based failover, including web service registration module, web service registration module, web service management module, main web service setting module, quality condition checking module, client confirmation module, communication module, and grouping module. ,

A web service registration step of registering information of a web service provided from a client and / or a service provider into the web service registration module through the web service registration module;

A web service grouping step of grouping the listed web services into the same type in the web service management module;

A test message transmission step of transmitting, by the main web service setting module, a test message to a constituent web service of a group formed in the web service grouping step;

A response time measuring step of measuring a response time of a corresponding web service in response to the test message in the main web service setting module;

A main web service setting step of determining a corresponding web service having the shortest time among the response times measured in the response time measuring step as a main web service of the web service group; And,

A web service access step of connecting to a main web service of a corresponding web service group through the communication module when a request message for a web service is received from the client;

It is a web service method that supports quality-based failure recovery that includes.

In the web service method according to the present invention,

A client confirming step of confirming a client sending the request message through the client confirming module;

The web service grouping step is to classify the same web service grouping for each client.

In the web service method according to the present invention,

A usage response time measuring step of measuring, by the quality condition checking module, a response time of a main web service connected to a client;

Modifying the main web service to perform the test message transmission step, the response time measurement step, and the main web service setting step sequentially if the measured response time of the use response time measurement step does not satisfy a setting condition Is more included.

In the web service method according to the present invention,

The main web service modification step is performed when the request message of the client requesting the web service of the web service group is received after it is confirmed that the response time of the web service does not satisfy the setting condition.

In the web service method according to the present invention,

The method further includes a grouping step of subdividing groupings of similar web services based on the synonyms by searching the information of the web services listed in the web service listing module.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram illustrating a web service system according to the present invention.

Web service system 100 according to the present invention, the web service registration module 170 in which the information of the web service is recorded; A web service registration module 120 for registering the information of the web service presented from the client 10 or the service provider 20 to the web service registration module 170; A web service management module 110 grouping the client 10 and the web service of the same kind according to the registered web service contents; A main web service setting module 140 for checking a response time of a response message received by transmitting a test message requesting a web service and determining a main web service of a corresponding group; A quality condition checking module 150 for driving the main web service setting module 140 by determining whether the response time satisfies a set quality condition; A client confirmation module 130 for checking the client 10 when receiving a web service request message from the client 10 receiving the web service; And a communication module 160 for connecting the web service set by the main web service setting module 140 to the corresponding client 10.

The web service is designed to support interoperability through a network by transmitting data structured with XML using an existing web technology such as HTTP through an interface of a format that can be interpreted by machines with different platforms. Defined as a software system. This is defined by the World Wide Web Consortium (W3C), the standardization body of the Web, and the web services described below will be used as a concept that includes data provided through such a system.

In addition, a web service is provided through three main elements, as shown in FIG. 3, which are a service provider, a service user (client), and a service registry, respectively. In order to achieve web services among them, promised messages, service information, and retrieval methods are required. The corresponding XML-based standards are Simple Object Access Protocol (SOAP), web services description language (WSDL), and UDDI. 4 shows the interrelationship of these standards and their function.

In an embodiment of the web service system according to the present invention, the web service registration module 170 is UDDI (universal description, discovery, and integration). The UDDI is an XML-based registry, that is, a service register, which consists of a businessEntity, businessService, bindingService, and tModel. Among these, tModel describes a specification of a service or a value set. Indicates whether the agreement is followed or what stack or standard

The UDDI (hereinafter referred to as web service registration module) 170 reflects the contents of the WSDL document as shown in FIG. 5, and the interface portion of the WSDL is defined as tModel. tModels can assign unique values to service interfaces through key values. So if you know the key value of a tModel, you can search it to find web services with the same interface.

However, although the key value of the tModel can be obtained through the search of the web service registration module 170, it is not easy for the user to know the key value of the tModel. Therefore, the web service system 100 according to the present invention uses the WSDL information mapped with the tModel. The mapping relationship is summarized in FIG. 6, whereby the service user searches the tModel name through the targetNamespace value of the previously used web service WSDL to find the same web service.

The web service registration module 120 enables web service registration by a client, and web service registration is performed through a WSDL.

The web service management module 110 (WSG) groups the same web services by searching and confirming a tModel in the web service registration module 170.

Grouping of web services according to the present invention is formed as follows.

FIG. 7 is a diagram illustrating an element schema for grouping between homogeneous web services in a web service system according to the present invention. FIG. 8 is a diagram illustrating an element schema of a WSGroup shown in FIG. 7, and FIG. This is a diagram showing the element schema of userInfos shown in FIG. 7.

Information for the web service system 100 according to the present invention can be divided into three categories. First, we need information describing the same services that can be replaced, information describing each web service's quality information, and finally, information describing the client's information and the required quality. There are many ways to describe this information, but here, we will describe the information based on XML that is easy to use and highly scalable. The embodiment according to the present invention designs and proposes a description language describing such contents, and the namespace of the design language uses “http://ec.cse.cau.ac.kr/qfs”.

The most representative elements of the quality of web services in a failover system are fault status and response time. In addition to this dynamic information, statistical quality factors such as response time deviations over a certain period of time, frequency of failures, and static quality factors, such as whether various web services related standards are supported, are used through namespace checking.

The necessary information is described using the QFTEnvelope element centering on the same web service group. The QFTEnvelope element, which is a root element, is divided into a WSGroup element that manages the same service and a userInfos element part that manages client information as shown in FIG.

The WSGroup element is an element for grouping homogeneous web services into a group and describing respective quality information. The WSGroup element schema is shown in FIG.

Since homogeneous web service groups have the same web service interface, the web service group is represented by representing the tModel key attribute value. The WSGroup element has as its child elements Service elements that contain information about each web service bound to the same web service. The Service element is identified by a location attribute value that represents the address of the service.

The userInfos element is an element for describing client-side information about users who use the corresponding web service group. The userInfos element schema is shown in FIG.

The userInfos element has a userInfo element as its child element, and each userInfo element identifies a user through an ipaddress attribute value. The userInfo element has a mainServiceLocation element and a RequiredQuality element, which describe the main web service and the desired quality criteria.

When the web service group of the same type is completed, the main web service setting module 140 determines a main web service by sending a test message to each of the web services belonging to the same type of web service group. . The web service system 100 according to the present invention publishes the WSDL changed to its own address so that the client can connect to the web service system 100 through this.

After the initial setting, the client 10 can use the web service through the web service system 100 according to the present invention. In the execution time step, the service request message sent by the client 10 is sent to the main web service and receives a response message. On the other hand, the quality condition check module 105 records the measured quality while continuing to measure the quality of the main web service. In this case, the quality condition includes a time required for the service provider 20 to transmit a response message after receiving the request message.

Subsequently, if the quality of the main web service does not meet the criteria, the main web service setting module 140 sends a test message to web services in the same web service group through the above-described process, and repeats the new main. Decide on a web service.

The communication module 160 transfers the request message of the client 10 to the main web service. At this time, the client 10 does not need any modification. The communication module 160 detects the main web service while communicating with the web service management module 110 and the main web service setting module 140 to move a request message and a response message between the client 10 and the service provider 20. Mediate.

On the other hand, the client identification module 130 confirms the originating IP of the attachment information of the request message sent from the client 10 to confirm the client 10.

By applying the confirmation of the client 10, the web service management module 110 may classify and group the same web services for each client.

Subsequently, the web service system 100 according to the present invention retrieves the information of the web service listed in the web service registration module 170 and divides the grouping of similar web services around the synonyms by the grouping module 111. This is further included.

In general, the web service registration module 170 is classified into documents in the information about the web service registered by the client 10. That is, the web service of the same kind is limited to the input contents of the client 10 for the corresponding web service. Therefore, even if any two web services are not classified as the same in the initial input information for the web service, if the two web services are identified as the same web service through the synonym search, they are grouped together in the request message of the client. To raise expectations.

This will be possible by displaying the synonyms in the same language in the WSDL representing the web service and mapping them to tModel.

Meanwhile, even when the service provider 20 adds a backup system, the same tModel is registered in the web service registration module 170 to notify the backup system, thereby increasing service reliability.

Subsequently, in order to overcome the failure that occurs when providing a web service, the client 10 transmits the SOAP request message sent by viewing the WSDL to another web service provider 20 of the same service group, and transmits the SOAP response message to the corresponding client 10. It is necessary to return to.

In the structure of SOAP, SOAP itself has no representation of the system's address, so there is no difference in the SOAP message itself that is sent to multiple identical services. SOAP is carried on other protocols such as HTTP, and addresses are handled by these protocols. Therefore, in this system, the SOAP message is sent by changing the address in the protocol without changing the SOAP message.

When the web service system 100 according to the present invention sets up the same web service group, the system 100 provides a WSDL in which only the connection address portion is replaced with its own. The part that describes the web service interface of WSDL is the same when providing the same service. The part that is related to the location of the system is the port element of the service.

The client 10 reports the WSDL of the web service system 100 according to the present invention and generates and sends a SOAP message as if using a normal web service. System 100 receives the SOAP message and mediates to the appropriate system.

2 is a flowchart sequentially illustrating a web service method according to the present invention.

Web service method according to the invention, the web service registration module 170, the web service registration module 120, the web service management module 110, the main web service setting module 140, the quality condition check module 150, In the web service system 100 supporting the quality-based failover, including the client confirmation module 130, the communication module 160, and the grouping module 111,

(1) Web service registration step of registering the information of the web service provided from the client 10 and / or service provider 20 to the web service registration module 170 through the web service registration module 120 (S20) );

As described above, the client 10 and / or the service provider 20 registers the web service in the web service registration module 170 through the web service registration module 120. As described above, the information of the web service input by the client 10 is registered as WSDL in the web service registration module 120, which is registered in the web service registration module 170 through mapping with UDDI.

(2) a web service grouping step (S30) of grouping the listed web services in the same type in the web service management module 110;

The web services listed in the web service registration module 170 are classified into web services of the same kind through tModel comparison, and are grouped into one web service group.

(3) a test message transmission step (S50) of transmitting the test message by the main web service setting module 140 to the constituent web service of the group formed in the web service grouping step;

When the same web service group is completed, the main web service setting module 140 finds a web service having an optimal quality condition among them. To this end, a test message for requesting a response message of the web service is transmitted to each service provider 20 of the corresponding web service group.

(4) in the main web service setting module, a response time measuring step (S60) of measuring a response time of a corresponding web service for the test message;

The service provider 20 receiving the test message transmits the corresponding response message to the main web service setting module 140. At this time, the arrival time of the response message is measured to check the web service of the service provider 20 having the shortest response time.

(5) a main web service setting step (S70) of determining a corresponding web service having the shortest time among the response times measured in the response time measuring step as a main web service of the web service group;

The identified web service is set as the main web service of the corresponding web service group, and the corresponding content is transmitted to the communication module 160 and the web service management module 110.

Subsequently, when a request message for a web service is received from the client 10, a web service access step of accessing the main web service of the corresponding web service group through the communication module 160 is further included.

In addition, a client confirmation step (S10) of confirming a client sending a request message through the client confirmation module 130 is further included, and the web service grouping step (S30), classifying the same web service grouping for each client. Proceed by

Through this, it is possible to provide web service by creating an optimal communication environment for each client.

On the other hand, the quality condition check module 150 may further include a usage response time measurement step (S80) for measuring the response time of the main web service connected to the client 10.

The quality condition checking module 150 checks the quality standard of the corresponding main web service while continuously measuring the response time of the main web service.

In general, the quality criteria may be initially set by the client 10 for the response time of the corresponding web service, and the statistics on the response time of the relevant web service while the web service system 100 according to the present invention is driven. We can calculate the optimal response time by calculating the, and may set this response time as a quality standard.

According to this quality standard, the quality condition check module 150 checks the response time of the web service.

In addition, when the measured response time of the use response time measurement step does not satisfy a setting condition, the test message transmission step (S50), the response time measurement step (S60), and the main web service setting step ( The main web service modification step (S90) to sequentially perform the step S70 is further included.

If the quality criteria are not met and the response time confirmed by the quality condition checking module 150 is not met, the main web service of the corresponding web service group is reset. Therefore, the test message transmission step (S50), the response time measurement step (S60), and the main web service setting step (S70) described above are sequentially performed.

At this time, when the main web service modification step (S90) is determined that the response time of the web service does not satisfy the setting condition (quality condition), when the request message of the client requesting the web service of the web service group is received. It is preferable to proceed from.

In more detail, when any client 10 accesses the web service system 100 according to the present invention to receive a web service, the main web service of the corresponding web service group is requested by the client 10. Sends a response message to the client 10. At this time, if the response time does not meet the quality condition, the existing main web service is provided to the client 10 in this case.

When the client 10 is suspended in this state and transmits a request message to receive the same web service, the web service system 100 according to the present invention sends a test message to the entire web service of the corresponding web service group of the web service. Send a response message, measure the response time, and transmit the web service having the shortest response time to the client 10 as well as setting it as a new main web service of the web service group.

This is because it is unreasonable to set an arbitrary web service as the main web service in advance because the response time of the web service changes to time.

Subsequently, a grouping step (S40) of retrieving the information of the web service listed in the web service registration module 170 and subdividing the grouping of the similar web service around the synonym may be further included.

Since the segmentation of the web service grouping has been described while describing the grouping module 111, the description thereof will be omitted.

10 is a table showing a result of calling a web service when the web service system is not used according to the present invention, and FIG. 11 is a table showing a call result of a web service when the web service system is used according to the present invention. 12 is a diagram showing a call result of a web service when a disturbance situation is created by removing a LAN line in the situation of FIG. 11. Referring to this, an environment for implementing a web service system 100 according to the present invention and a result thereof are described. It will be described, thereby showing the effect of the web service system 100.

The web system system 100 according to the present invention is implemented in the Java language, and Apache Axis is used as a web service engine required for the web service provider or the client side.

For the experiment, we created a method in the form of 'double getStockPrice (String)' and published it as a web service, which returns a value that changes by ± 100 in a sinusoidal form within a certain range every 10 seconds. For example, in section 4.2, the value is increased by 100 every 10 seconds from 3200 to 3800 and decreases by 100 every 10 seconds from 3800 to 3200.

The service provider 20 is deployed identically on different servers, and since the experiment is conducted in the LAN environment, each web service reads the argument value of the sleep () command from an external file and delays the delay time. The dynamic setting allows a change in response time.

The client 10 calls the above web service at the set time interval and the number of times and outputs the result value to the screen.

The evaluation was divided into two parts, functional evaluation and performance evaluation.

In evaluating the functionality of the system, the client invokes the service once every 5 seconds.

Table 1 shows the result of calling the web service when the web service system is not used, and Table 2 shows the result of calling the web service when the web service system is used according to the present invention. In the situation of Table 2, when the LAN condition is removed by removing the LAN line, the call result of the web service is shown.

 Table 1 shows the result of calling the web service directly without using the system 100. When the delay time of 11000ms is set in the middle, a section in which the value changes to 100 or more occurs.

Tables 2 and 3 show the results when the system 100 is used, and the threshold of the response time set in the system 100 is 5000 ms. Table 2 shows the delay time of 11000ms as above, and Table 3 shows the failure condition by removing the LAN line.

The results in Table 2 and Table 3 show that when the response time exceeds 5000ms, the switch is switched to the same other web service with a response time of 3000ms.

Performance evaluation is a system for the occasional failure situation should not burden the use of the usual services, when the web service is called through the system 100 and the time it takes to call the web service without going through the system 100 Measure and compare the time taken. For each, the client made 50 calls every 2 seconds to find the maximum, minimum, and average response times. 10 is the result. The unit is ms (millisecond), and there is a difference of about 25ms between the two. That is, it takes about 25ms to go through the web service system 100 according to the present invention.

Count One 2 3 4 5 Result value 3600 3600 3700 3700 3800 Response time 30 40 20 10 11016 Count 6 7 8 9 10 Result value 3800 3600 3400 3300 3300 Response time 11026 11026 11026 11026 11026

Count One 2 3 4 5 Result value 3400 3500 3500 3600 3700 Response time 62 50 48 42 5140 Count 6 7 8 9 10 Result value 3700 3800 3700 3700 3600 Response time 3050 3045 3043 3038 3040

Count One 2 3 4 5 Result value 3200 3300 3300 3400 3500 Response time 52 48 42 38 5118 Count 6 7 8 9 10 Result value 3500 3600 3700 3700 3800 Response time 3040 3042 3038 3036 3036

According to the present invention as described above, the connection with the service provider providing the web service, as well as the way to overcome the degradation of the quality of the web service can be presented, and the optimal environment for providing the web service to the continuous quality It can be maintained by comparison.

Claims (8)

A web service registration module in which information of a web service is recorded; A web service registration module for registering information of a web service presented from a client or a service provider into the web service registration module; A web service management module for grouping the client and the same web service according to the content of the registered web service; A main web service setting module for checking a response time of a response message received by transmitting a test message requesting a web service, and determining a main web service of a corresponding group; A quality condition checking module which determines whether the response time satisfies a set quality condition and drives the main web service setting module; A client confirmation module for identifying a corresponding client when a web service request message of a client receiving a web service is received; And, A communication module for connecting the web service set in the main web service setting module and the corresponding client; Web service system that supports quality-based failover, characterized in that it includes. The method of claim 1, And a grouping module for retrieving the information of the web services listed in the web service registration module and subdividing the grouping of similar web services based on the synonyms. The method according to claim 1 or 2, The web service registration module is UDDI; The web service management module may be driven by mapping the UDDI and WSDL such that a tModel constituting the UDDI is defined as an interface of a WSDL; Web service system that supports quality-based failover, characterized in that. In the web service system supporting quality-based failover, including web service registration module, web service registration module, web service management module, main web service setting module, quality condition checking module, client confirmation module, communication module, and grouping module. , A web service registration step of registering information of a web service provided from a client and / or a service provider into the web service registration module through the web service registration module; A web service grouping step of grouping the listed web services into the same type in the web service management module; A test message transmission step of transmitting, by the main web service setting module, a test message to a constituent web service of a group formed in the web service grouping step; A response time measuring step of measuring a response time of a corresponding web service in response to the test message in the main web service setting module; A main web service setting step of determining a corresponding web service having the shortest time among the response times measured in the response time measuring step as a main web service of the web service group; And, A web service access step of connecting to a main web service of a corresponding web service group through the communication module when a request message for a web service is received from the client; Web service method that supports the quality-based failover, characterized in that it comprises a. The method of claim 4, wherein A client confirming step of confirming a client sending the request message through the client confirming module; The web service grouping step, the web service method for supporting quality-based failover, characterized in that the classification of the web service grouping by the client proceeds. The method according to claim 4 or 5, A usage response time measuring step of measuring, by the quality condition checking module, a response time of a main web service connected to a client; Modifying the main web service to perform the test message transmission step, the response time measurement step, and the main web service setting step sequentially if the measured response time of the use response time measurement step does not satisfy a setting condition Web service method for supporting the quality-based failover, characterized in that it further comprises. The method of claim 6, The main web service modification step is characterized in that proceeds from when the request message of the client requesting the web service of the web service group is received after it is confirmed that the response time of the web service does not satisfy the setting condition. Web service method to support infrastructure failover. The method according to claim 4 or 5, And a grouping step of subdividing the grouping of similar web services based on the synonyms by searching for the information of the web services listed in the web service registration module.

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