CN113411231A

CN113411231A - CORBA middleware communication delay performance optimization method

Info

Publication number: CN113411231A
Application number: CN202110661523.0A
Authority: CN
Inventors: 吕浩; 沈建飞; 刘文科; 何川; 耿岩; 孙晓毓; 周琪; 杨少华; 张拓
Original assignee: CETC 20 Research Institute
Current assignee: CETC 20 Research Institute
Priority date: 2021-06-15
Filing date: 2021-06-15
Publication date: 2021-09-17

Abstract

The invention provides a CORBA middleware communication delay performance optimization method. The keyword oneway is used to modify the communication interface between the client and the server, so that the interface becomes a one-way operation, that is, after the client sends a request, the CORBA intermediate The software forwards the call request to the server-side application for processing, and the client does not need to wait for the server-side response, and immediately returns to perform subsequent processing. The reliability of the implementation method is verified by calculating the packet loss rate and packet error rate. On the premise of ensuring reliable transmission, the present invention can simplify the communication process, improve the communication efficiency, and reduce the communication delay. In addition, the method is simple to implement, has nothing to do with the real-time performance of the operating system, and has nothing to do with the type of data transmitted, and the server receives the There is no packet loss, no error packets, and guaranteed communication reliability. The method can simplify the communication process and reduce the communication delay.

Description

CORBA middleware communication delay performance optimization method

Technical Field

The invention relates to the field of radio middleware, in particular to a plurality of technologies such as middleware, an object-oriented development mode, an Interface Definition Language (IDL), a soft bus and the like. The invention utilizes the keyword oneway to modify the communication interface between the client and the server, can simplify the information interaction process of the CORBA middleware, and reduces the communication delay of the middleware on the basis of ensuring reliable transmission.

Background

CORBA middleware is an object-oriented middleware standard promulgated by the Object Management Group (OMG), a common service between operating systems and application software. The core of CORBA is an Object Request Broker (ORB), which encodes/decodes the message communicated between the client and the server to generate a format independent of the programming language, and completes the sending and receiving of the message through the default communication mechanism of ethernet, so that the client does not need to consider the physical location, implementation details and other contents of the server object, and can play a role of a soft bus shielding the differences of the processor, the operating system and the programming language. These characteristics allow CORBA to be adopted by the SCA specification and applied to software radio systems.

Due to the introduction of the middleware, the communication delay among the components in the software radio system is invisibly increased, and the communication efficiency of the software radio system is directly determined by the performance of the CORBA communication delay, so that how to reduce the CORBA middleware communication delay is the research focus of the invention.

At present, in the aspect of middleware time delay optimization, part of researchers adopt a thread pool, a priority mechanism and a global scheduling service to strengthen the management and control of system resources, and the method focuses on optimizing an operating system instead of optimizing a middleware communication process and is not suitable for an operating system with poor real-time performance, such as Linux; part of researchers adopt other communication mechanisms (such as RapidIO and the like) to realize CORBA middleware communication, the method is complex to realize, and the CORBA middleware based on non-Ethernet is not widely applied; some researchers have adopted simple types as much as possible for transmitted data from the perspective of encoding and decoding to improve the encoding and decoding rate, but the method is not suitable for application scenarios with more complex data transmission.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a CORBA middleware communication delay performance optimization method. In order to reduce the communication delay of the middleware, improve the operating efficiency of a software radio system and meet the requirement of high real-time performance, the invention analyzes the working principle of CORBA and provides a middleware communication delay performance optimization method based on keyword oneway.

The invention uses the keyword oneway to modify the communication interface between the client and the server, so that the interface becomes unidirectional operation, namely after the client sends a request, the CORBA middleware forwards the call request to the server for processing, and the client does not need to wait for the response of the server and immediately returns to execute the subsequent processing, thereby simplifying the communication flow and having more efficient information exchange. However, the reliability of the unidirectional operation cannot be guaranteed, and the reliability of the implementation method is verified by calculating the packet loss rate and the packet error rate.

The technical scheme adopted by the invention for solving the technical problem comprises the following steps:

[ step 1] define oneway operation;

modifying an interface for completing data communication between the client and the server by using the keyword oneway, and deleting the custom exception to obtain an IDL file;

step 2, verifying the feasibility of the implementation method;

mapping the IDL file into a required language by using an IDL interface generator to generate a corresponding root code file and a corresponding frame file; adding test codes in the root code file and the frame file, and compiling to generate an executable file;

running an executable file, starting a test thread, calling a communication interface to start testing, and recording GIOP (group operation protocol) messages of communication between a client and a server;

if the server does not send the Response message in the GIOP message to the client and the Response _ flags field of the Request message in the GIOP message is 00, the operation is an oneway operation, the realization method is feasible, and step 3 is executed; otherwise, executing step 1;

step 3, verifying the reliability of the implementation method;

the reliability is verified by calculating the packet loss rate and the packet error rate, and the specific steps are as follows:

starting a testing thread, calling a communication interface between a client and a server for N times, and counting the number N of received data packets at the server₁And calculating packet loss rate L_NCalculated as follows:

L_N＝(N-N₁)/N*100％ (1)

comparing whether the length of the data packet received by the server is equal to the length of the data packet sent by the client, comparing whether the content of the data packet received by the server is equal to the content of the data packet sent by the client, if the length is equal and the content is equal, the packet is a correct packet, otherwise, the packet is an error packet, and counting the number N of the error packets₂Calculating the packet error rate W_NCalculated as follows:

W_N＝N₂/N*100％ (2)

if there is no packet loss (i.e. L)_N0%) and no error packets (i.e., W)_N0%), indicating a reliable transmission, step 4 is performed; otherwise, skipping to execute the step 1;

step 4, calculating the communication time delay;

starting a test thread, calling a communication interface between a client and a server M times, and recording the time t for starting to call the communication interface₁Recording the interface end time t after M times of calling₂Calculating the communication time delay according to the formula (3):

D_M＝(t₂-t₁)/M (3)

obtaining a communication delay D_M。

In step 2, the languages include C, C + + and Java, and the IDL file is mapped to a corresponding language, and the C + + language is adopted in the present invention.

In order to improve the accuracy, the calling is required for multiple times, and the value range of N in the step 3 is N not less than 10000.

In order to improve the accuracy, the calling is required for multiple times, and the value range of M in the step 4 is M not less than 10000.

The method has the advantages that the communication interfaces of the client side and the server side of the middleware are modified by using the oneway keyword, so that the communication flow can be simplified, the communication efficiency is improved, and the communication time delay is reduced on the premise of ensuring reliable transmission.

The invention adopts the keyword oneway to modify the interfaces of the data communication between the client and the server, and deletes the custom exception, because CORBA adopts the default Ethernet TCP/IP protocol as the bottom layer transmission mechanism, the data received by the server has no packet loss and no error packet, and the communication reliability is ensured.

Drawings

FIG. 1 is a diagram of a one-way call.

Fig. 2 is a schematic diagram of a two-way call.

Fig. 3 is a schematic diagram illustrating message interaction between oneway operation client and server GIOP.

Fig. 4 is a schematic diagram of message interaction between the twoway operation client and the GIOP service end.

Fig. 5 shows the oneway operation Request message contents.

Fig. 6 shows the contents of the twoway action Request message.

Fig. 7 is a diagram illustrating middleware communication delay.

Fig. 8 is a diagram comparing 10000 oneway and twoway communication delays for calling the communication interface.

Detailed Description

The invention is further illustrated with reference to the following figures and examples.

The invention provides a middleware communication time delay optimization method based on keyword oneway, and takes omniORB as an example for testing and verification, wherein omniORB is a CORBA middleware product with wide application.

oneway is a key defined in the IDL specification that indicates that the operation is unidirectional. Fig. 1 and 2 are schematic diagrams of a one-way call and a two-way call. Compared with bidirectional calling, after the client side with unidirectional calling sends a request, the CORBA middleware forwards the calling request to the server side application for processing, and the client side does not need to wait for the response of the server side and immediately returns to execute subsequent processing, so that the transmission efficiency of information can be improved by using oneway keyword modification operation. However, if the unidirectional operation is executed, the client does not know whether the operation is normally called, and the reliability cannot be ensured.

[ step 1] define oneway operation

The invention defines a simple interface with the function name of pushPacket. The interface only realizes data transmission from the client to the server and has no other functions, the input parameter of the function is transmission test data, and the self-defined exception is ERROR _ BAD _ SIZE.

According to the IDL specification, the interface defaults to non-oneway operation (namely towway), adds oneway keywords in front of the pushPacket, and deletes self-defined exception to obtain an IDL file of the oneway operation.

[ step 2] verification of the feasibility of the method

The IDL file is mapped into a C + + language to generate a corresponding root code file and a corresponding frame file; adding test codes in the root code file and the frame file, and compiling to generate an executable file; and running the executable file, starting a test thread, calling a communication interface, and recording GIOP (group operation protocol) messages of communication between the client and the server.

Fig. 3 and 4 are schematic diagrams of message interaction between the oneway operation and the twoway operation client and the server GIOP. For the twoway operation, the client and server communicate as follows.

1) The client sends a LocateRequest message to the server;

2) after receiving the LocateRequest message, the server sends a LocateRely message to the client, and confirms that the appointed object request is accepted;

3) the client sends a Request message to the server, calls a communication interface and starts communication;

4) and the Response message sent by the server to the client represents whether the calling is successful or not.

For the oneway operation, the LocateRequest and LocateReply messages communicated between the client and the server are identical to towway, the Response _ flags field of the Request message is different from towway, and the biggest difference is that the oneway operation server does not send a Response message to the client.

Request messages of oneway operation and towway operation as shown in fig. 5 and 6, it is known from the frame format that the response _ flags field of the message indicates whether the operation is one oneway operation. oneway operation is 00 and twoway operation is 03, conforming to the frame format definition. The result shows that the implementation method for modifying the communication interface by using oneway is feasible.

[ step 3] verification of the reliability of the implementation method

Since the user-defined exception ERROR _ BAD _ SIZE is deleted, the reliability of the implementation method is verified by calculating the packet loss rate and the packet ERROR rate. The packet loss rate and the packet error rate can be calculated according to the equations (1) and (2), respectively.

The test results are shown in table 1, where table 1 is statistics of packet loss rate and packet error rate 10000 times by calling oneway operation interface.

Byte number/KB	Packet loss rate	Packet error rate
			1	0％	0％
3	0％	0％
			5	0％	0％
7	0％	0％

When N is 10000, data with different lengths (1KB, 3KB, 5KB, and 7KB) is transmitted, and there is no packet loss or no packet error. The N value is changed, and data with different lengths (1KB, 3KB, 5KB and 7KB) is sent, and the conclusion is the same. The result shows that the implementation method for modifying the communication interface by using oneway has no packet loss and no error packet, because the bottom layer adopts the communication protocol of TCP/IP, the calling of the operation is ensured to be reliable transmission.

Step 4, calculating the communication time delay. The middleware communication delay refers to the time required for the client and the server to complete a communication process (i.e., call a pushPacket interface), as shown in fig. 7. The communication delay can be calculated according to equation (3).

As shown in fig. 8, when M is 10000, data (for example, 1KB) with the same length is transmitted, and the communication interface is decorated with the keyword oneway, so that the communication delay can be effectively reduced. The same conclusion is reached by changing the data length (3KB, 5KB, 7KB) of the transmitted data. The result shows that the implementation method for modifying the communication interface by using oneway can reduce the communication delay by nearly 60 percent.

Claims

1. a CORBA middleware communication delay performance optimization method is characterized in that comprising the following steps:

[Step 1] Define the oneway operation;

Use the keyword oneway to modify the interface between the client and the server to complete data communication, and delete the custom exception to get the IDL file;

[Step 2] Verify the feasibility of the implementation method;

Use the IDL interface generator to map the IDL file to the required language, and generate the corresponding root code file and framework file; add test code to the root code file and the framework file, and compile and generate executable files;

Run the executable file, start the test thread, call the communication interface to start the test, and record the GIOP message communicated between the client and the server;

If the server does not send the Response message in the GIOP message to the client, and the response_flags field of the Request message in the GIOP message is 00, it indicates that the operation is a oneway operation, indicating that the implementation method is feasible, and execute step 3; otherwise, execute step 3 1;

[Step 3] Verify the reliability of the implementation method;

The reliability is verified by calculating the packet loss rate and packet error rate. The specific steps are:

Start the test thread, call the communication interface between the client and the server N times, count the number of received data packets N ₁ on the server, and calculate the packet loss rate. The packet loss rate L _N is calculated as follows:

L _N =(NN ₁ )/N*100% (1)

Compare whether the length of the data packet received by the server is equal to the length of the data packet sent by the client, and compare whether the content of the data packet received by the server is the same as the content of the data packet sent by the client. is a correct packet, otherwise the packet is an error packet, count the number of error packets N ₂ , calculate the error packet rate, and the error packet rate W _N is calculated as follows:

W _N =N ₂ /N*100% (2)

If there is no packet loss and no error packets, it indicates that the transmission is reliable, and go to step 4; otherwise, skip to step 1;

[Step 4] Calculate the communication delay;

Start the test thread, call the communication interface between the client and the server M times, record the time t ₁ when the communication interface starts to be called, record the end time t ₂ of the interface after calling M times, and calculate the communication delay. The communication delay is calculated according to formula (3). :

D _M =(t ₂ -t ₁ )/M (3)

The communication delay _DM is obtained.

2 . The method for optimizing the communication delay performance of CORBA middleware according to claim 1 , wherein in step 2, the languages include C, C++ and Java, and the IDL files are mapped to corresponding languages. 3 .

3 . The method for optimizing the communication delay performance of CORBA middleware according to claim 1 , wherein the value range of N in step 3 is N≧10000. 4 .

4 . The method for optimizing the communication delay performance of CORBA middleware according to claim 1 , wherein the value range of M in step 4 is M≧10000. 5 .