Abstract:
Providing efficient data replication for a transaction processing server is provided. A notification is received from the transaction processing server which completes a transaction of a message. The notification includes a message digest and a message identifier. The message identifier in the received notification is compared with a stored message identifier. In response to a match of the comparing of the message identifier, the message digest in the received notification is compared with a stored message digest. In response to a match of the comparing of the message digest, a stored input message is directly stored in a physical storage.

Description:
This Application is a counterpart of and claims the benefit of priority to Taiwan Patent Application No. 102111625, filed on Mar. 30, 2013, the contents of which are hereby incorporated by reference. 
     BACKGROUND 
     1. Field 
     The present invention relates to efficient data replication and backup, and more particularly, to a method, a backup server, and a computer program product for enabling a transaction processing server to perform efficient data replication and backup. 
     2. Description of the Related Art 
     From the perspective of most enterprise applications, especially B2B applications (in the B2B message-related field, for example), the capability of maintaining non-repudiation of data is not only inevitably an important dimension of the applications, but also the key to the success of enterprise business. Hence, most enterprise applications require keeping received transaction data (wire-in) and sending transaction data (wire-out) to ensure that the applications will each have a copy which serves as a piece of evidence and thus effectuates non-repudiation of data. However, as in the case of most B2B message applications, the payloads of files increase greatly (to, say, 100M-1G) with the size or quantity of the files; as a result, it poses an enormous challenge to most B2B applications in terms of storing the payloads efficiently and still maintaining high message throughout (i.e., the number of transactions conducted per second). 
       FIG. 1  is a schematic view, of a message process flow of an illustrative framework of a conventional typical B2B application. A transaction processing server  110  provides an application  112  (such as stock trading) for receiving an input message  102  from the client. The input message  102  either originates from an external client device directly or is sent to the transaction processing server  110  via a networking device  100 . The input message  102  is a packet or a transaction. The networking device  100  is a device capable of controlling the direction of the flow of network packets and is exemplified by an exchanger, a router, or a hub. For the details of the framework of the networking device  100 , make reference to Cisco&#39;s exchanger product Cisco Catalyst 3550 Series Switch. The transaction processing server  110  stores correctable data by a transaction and usually applies to systems of banking, stocks and securities transaction. A transaction requests that data stored in a transaction processing server be read, written, or updated. In general, a transaction includes ordering, purchasing, changing, creating, and deleting. For further details of the transaction processing server, make reference to WebSphere DataPower B2B Appliance v5.0. 
     In general, the process flow of the B2B application is as follows: 
     1) After the transaction processing server  110  has received the input message  102 , the input message  102  is sent from the kernel space of the transaction processing server  110  to the application  112  on a user space. 
     2) The application  112  of the transaction processing server  110  analyzes and processes the input message  102 . Afterward, the input message  102  is sent from the user space to the kernel space, so as to be replicated by a transaction backup server  120 . The transaction backup server  120  gives backup to a local storage or sends it to a remote storage server (such as NES/CIFS/ISCSI) of NAS; meanwhile, the message is transmitted via a network. For details of the storage server, make reference to NAS Server on Ubuntu 11.10. When necessary, the input message  102  which has been processed can also be sent from the user space to the kernel space, so as to be replicated by the transaction backup server  120 . 
     3) An operating system of the transaction backup server  120  copies the input message  102  received from the transaction processing server  110  from the kernel space to a daemon, such as an NFS daemon, on the user space. 
     4) The NFS daemon stores the input message  102  in a physical storage, such as a hard disk drive or an array of hard disk drives (RAID), of the transaction backup server  120 . 
     The aforesaid conventional process flow involves a latency of heavy I/O operation, regardless of whether network-based transmission takes place between the user space and the kernel space, or between the transaction processing server  110  and the transaction backup server  120 . Hence, the latency of the heavy I/O operation becomes the performance bottleneck of overall throughout. 
     Accordingly, it is advantageous to reduce unnecessary I/O operation between the transaction processing server  110  and the transaction backup server  120 . 
     SUMMARY 
     According to one or more embodiments of the present invention, a transaction backup server monitors (or, also known as “sniffers”) and replicates a message packet whose destination is a transaction processing server, such that the transaction processing server and the transaction backup server receive the transaction message simultaneously to thereby reduce unnecessary I/O copying operation. 
     The present invention, in an embodiment thereof, provides a method for enabling a transaction processing server to perform efficient data replication. The method comprises the steps of: receiving a notification from the transaction processing server having completed a transaction of a message, the notification including a message digest and a message identifier (message ID); comparing the message ID in the notification received with a stored message ID; comparing the message digest in the notification received with a stored message digest in response to a match of the message ID; and storing a stored input message directly in a physical storage in response to a match of the message digest. 
     According to another embodiment of the present invention, a computer program product comprises a computer-readable medium having a program code stored therein to implement the aforesaid method when executed on an information apparatus, thereby enabling a transaction processing server to perform efficient data replication. 
     According to another embodiment of the present invention, an information apparatus comprises a bus, a memory, and a processing unit. The memory is connected to the bus, wherein the memory includes instructions. The processing unit is connected to the bus, wherein the processing unit executes the instructions to implement the aforesaid method, thereby enabling a transaction processing server to perform efficient data replication. 
     Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with embodiments of the present invention should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, discussion of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment. 
     Furthermore, the described features, advantages, and characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the invention may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order that the advantages of embodiments of the invention will be readily understood, a more particular description of the embodiments of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the embodiments of the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings. 
         FIG. 1  is a schematic view of a message process flow of an illustrative framework of a conventional typical B2B application; 
         FIG. 2  is a block diagram of an illustrative hardware environment of a transaction processing server or a transaction backup server according to an embodiments of the present invention; 
         FIG. 3  is a schematic view of a message process flow of an illustrative framework of a B2B application according to an embodiment of the present invention; 
         FIG. 4  is a flow chart of a method for a packet sniffing module of the transaction backup server according to an embodiment of the present invention; and 
         FIG. 5  is a flow chart of a method for a storage buffer managing module of the transaction backup server according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     In order that the advantages of embodiments of the invention will be readily understood, a more particular description of the embodiments of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the embodiments of the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings. 
     As will be appreciated by one skilled in the art, the embodiments of the present invention may be embodied as an appliance, a method, or a computer program product. Accordingly, embodiments of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.), or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module,” or “system.” Furthermore, embodiments of the present invention may take the form of a computer program product embodied in any tangible storage medium of expression having computer-usable program code embodied in the storage medium. 
     Any combination of one or more computer-usable or computer-readable storage medium(s) may be utilized. The computer-usable or computer-readable storage medium may be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. More specific examples (a non-exhaustive list) of the computer-readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a transmission media such as those supporting the Internet or an intranet, or a magnetic storage device. Note that the computer-usable or computer-readable storage medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via, for instance, optical scanning of the paper or other medium, then compiled, interpreted, or otherwise processed in a suitable manner, if necessary, and then stored in a computer memory. In the context of this document, a computer-usable or computer-readable storage medium may be any medium that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-usable storage medium may include a propagated data signal with the computer-usable program code embodied therewith, either in baseband or as part of a carrier wave. The computer usable program code may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc. 
     Computer program code for carrying out operations of embodiments of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user&#39;s computer, partly on the user&#39;s computer, as a stand-alone software package, partly on the user&#39;s computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer or server may be connected to the user&#39;s computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). 
     The present invention is described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. 
     These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks. 
     The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. 
     Referring now to  FIG. 1  through  FIG. 5 , systems, methods, and computer program products are illustrated as structural or functional block diagrams or process flowcharts according to various embodiments of the present invention. The flowcharts and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions. 
       FIG. 2  is a block diagram of an illustrative hardware environment of a transaction processing server or a transaction backup server  202  according to the present invention. In an exemplary embodiment, a server is a universal desktop computer comprising: a processor for executing various applications; a storage device for storing various information and program code; a display device, a communication device, and an input/output device which function as interfaces for communicating with a user; and a peripheral component or other components serving a specific purpose. In another embodiment, the present invention is implemented in another way and thus having less or more other devices or components. The network can also be implemented in any form of a connection, including a fixed connection, such as a local area network (LAN) or a wide area network (WAN), or getting connected to the Internet through a dial-up connection provided by an Internet service provider (ISP). The network connection is not restricted to cable connection and wireless connection; instead, it can also be implemented by wireless connection in the form of a GSM connection or a Wi-Fi connection for communicating with a client computer. The network further comprises other hardware and software components (not shown), such as an additional computer system, router, and firewall. 
     As shown in  FIG. 2 , a server  202  includes a processor unit  204  coupled to a system bus  206 . Also coupled to system bus  206  is a video adapter  208 , which drives/supports a display  210 . System bus  206  is coupled via a bus bridge  212  to an Input/Output (I/O) bus  214 . Coupled to I/O bus  214  is an I/O interface  216 , which affords communication with various I/O devices, including a keyboard  218 , a mouse  220 , a Compact Disk-Read Only Memory (CD-ROM)  222 , a floppy disk drive  224 , and a flash drive memory  226 . The format of the ports connected to I/O interface  216  may be any known to those skilled in the art of computer architecture, including but not limited to Universal Serial Bus (USB) ports. 
     The server  202  is able to communicate with a service provider server  252  via a network  228  using a network interface  230 , which is coupled to system bus  206 . Network  228  may be an external network such as the Internet, or an internal network such as an Ethernet or a Virtual Private Network (VPN). Using network  228 , the server  202  is able to access service provider server  252 . 
     A hard drive interface  232  is also coupled to system bus  206 . Hard drive interface  232  interfaces with a hard drive  234 . In a preferred embodiment, hard drive  234  populates a system memory  236 , which is also coupled to system bus  206 . Data that populates system memory  236  includes server  202 &#39;s operating system (OS)  238  and application programs  244 . 
     OS  238  includes a shell  240 , for providing transparent user access to resources such as application programs  244 . Generally, shell  240  is a program that provides an interpreter and an interface between the user and the operating system. More specifically, shell  240  executes commands that are entered into a command line user interface or from a file. Thus, shell  240  (as it is called in UNIX®), also called a command processor in Windows®, is generally the highest level of the operating system software hierarchy and serves as a command interpreter. The shell provides a system prompt, interprets commands entered by keyboard, mouse, or other user input media, and sends the interpreted command(s) to the appropriate lower levels of the operating system (e.g., a kernel  242 ) for processing. Note that while shell  240  is a text-based, line-oriented user interface, the present invention will equally well support other user interface modes, such as graphical, voice, gestural, etc. As depicted, OS  238  also includes kernel  242 , which includes lower levels of functionality for OS  238 , including providing essential services required by other parts of OS  238  and application programs  244 , including memory management, process and task management, disk management, and mouse and keyboard management. 
     The hardware framework of other computer or server  252  is identical or similar to that of the server  202 , or is any conventional basic framework, and the present invention is not limited thereto. For example, other computer  252  is a desktop computer, a notebook computer, a personal digital assistant (PDA), or a smartphone. However,  FIG. 2  and the above examples are not restrictive of the present invention. Other computer  252  comprises a browser. The browser comprises a program module and instructions. The program module and commands comply with the Hypertext Transfer Protocol (HTTP) whereby a World Wide Web (WWW) client (i.e., other computer or server  252 ) sends and receives web-based messages through the Internet and communicate with the server  202 . 
     The application program  244  comprises a packet sniffing module  246  and a storage buffer managing module  248 . The packet sniffing module  246  and the storage buffer managing module  248  include program modules and instructions. The program modules and instructions communicate with another computer or server  252  to sniff and replicate a message packet delivered to a destination. In fact, the packet sniffing module  246  and the storage buffer managing module  248  are either modules within an application program or are implemented by means of a daemon (that is, come in the form of modules of an application program or come in the form of a daemon). However, in another embodiment, the packet sniffing module  246  and the storage buffer managing module  248  are implemented by a program in another form. The packet sniffing module  246  and the storage buffer managing module  248  include codes for carrying out the processes illustrated with  FIGS. 4 and 5  and described below. 
     The hardware elements depicted in the server  202  are not intended to be exhaustive, but rather are representative to highlight essential components required by the present invention. For instance, the server  202  may include alternate memory storage devices such as magnetic cassettes, Digital Versatile Disks (DVDs), Bernoulli cartridges, and the like. These and other variations are intended to be within the spirit and scope of the present invention. 
       FIG. 3  is a schematic view of a message process flow of an illustrative framework of a B2B application according to an embodiment of the present invention. As shown in the diagram, the illustrative framework of a B2B application comprises a transaction processing server  310  and a transaction backup server  320  positioned in the same network segment. The transaction processing server  310  provides an application  312  for receiving an input message  302  from the client. The input message  302  either originates from an external client device (such as a computer) directly or is sent to the transaction processing server  310  via a networking device  300 . The networking device  300  is a device capable of controlling the direction of the flow of network packets and is exemplified by an exchanger, a router, or a hub. In an embodiment of the present invention, the process flow of the B2B application is as follows: 
     1) The transaction processing server  310  configures the IP address and port of the transaction backup server  320  specified to thereby create a message transmission path. Hence, the credential of the transaction processing server  310  is transmitted to a reservation buffer managing module  324  of the transaction backup server  320  so as to enable the decryption operation of a transmission layer (for example, decryption of SSL). In fact, it is feasible that the transaction backup server  320  be configured as a reliable server for the transaction processing server  310  beforehand; as a result, the transmission of the credential is optional rather than required. 
     2) To allow the exchanger or hub to send the input message  302 , the application  312  on the user space receives the input message  302  from the kernel space of the transaction processing server  310 . 
     3) A packet sniffing module  322  of the transaction backup server  320  monitors continuously a message packet whose destination is the transaction processing server  310 , and thus the packet sniffing module  322  also receives a copy of the input message  302 . With the credential attributed to the transaction processing server  310  and received by the reservation buffer managing module  324 , the packet sniffing module  322  decrypts the input message  302  and stores the input message  302  in a packet cache buffer  326 . 
     The message digest and message ID are stored in the reservation buffer managing module  324 . The message digest is a checksum of the contents of the message or is obtained by means of hashing or MD5. 
     4) After the transaction processing server  310  has completed the message transaction and decided to keep (or discard) the message, a reservation buffer managing module  314  of the transaction processing server  310  sends a notification to the reservation buffer managing module  324  of the transaction backup server  320 . The notification comprises the message digest and the message ID. The message digest and the message ID are for use in identifying the transaction of a message. 
     The reservation buffer managing module  324  compares the message digest and message ID in the notification received and the message digest and message ID stored in the reservation buffer managing module  324 . If the comparison yields a match in whole, the packet cache buffer  326  will directly copy the stored input message  302  to a physical storage  328 , such as a hard disk drive or a RAID. 
     If the matching process has not been finished in a specific period of time, the reservation buffer managing module  324  will simply discard message data stored in the packet cache buffer  326  and indicated by the same message ID. 
     5) After the aforesaid comparing step, the reservation buffer managing module  324  sends an affirmative confirmation (or a negative confirmation) to the reservation buffer managing module  314  of the transaction processing server  310 . If the reservation buffer managing module  314  receives a negative confirmation, the whole message will be sent to the transaction backup server  320  and stored therein. In doing so, an embodiment of the present invention ensures that message data will be kept securely, even in the worst situation, such as timeout. 
       FIG. 4  is a flow chart of a method for a packet sniffing module of the transaction backup server according to an embodiment of the present invention.  FIG. 4  illustrates an embodiment of the present invention in conjunction with  FIG. 3 . 
     Step  400 : the packet sniffing module  322  monitors continuously message data whose destination is the transaction processing server  310  and thus also receives a copy of the input message data  302 . 
     Step  402 : determine whether the destination of a message packet received is the transaction processing server  310 , and discard the received message packet directly if its destination is not the transaction processing server  310  (step  404 ). 
     Step  406 : determine whether to enable decryption operation of a transmission layer (for example, decryption of SSL) to thereby decrypt the received message packet, that is, determine whether the decryption is enabled by a credential received by the reservation buffer managing module  324 . Perform message packet decryption when the determination is affirmative (step  408 ). 
     Step  410 : determine whether the packet cache buffer  326  is full. Introduce the message packet into the packet ache buffer  326  when it is determined that the packet cache buffer  326  is not full (step  412 ). 
     Step  414 : allocate additional kernel cache by memory mapping, such as mmap, when it is determined that the packet cache buffer  326  is full. 
       FIG. 5  is a flow chart of a method for a storage buffer managing module of the transaction backup server according to an embodiment of the present invention.  FIG. 5  illustrates an embodiment of the present invention in conjunction with  FIG. 3 . 
     The reservation buffer managing module  324  compares the message digest and message ID in the notification received and the message digest and message ID stored in the reservation buffer managing module  324 . If the comparison yields a match in whole, the packet cache buffer  326  will directly copy the stored input message  302  to the physical storage  328 , such as a hard disk drive or a RAID. 
     Step  500 : as described before, after the transaction processing server  310  has completed the message transaction and decided to keep (or discard) the message, the reservation buffer managing module  314  of the transaction processing server  310  sends a notification to the reservation buffer managing module  324  of the transaction backup server  320 . The storage buffer managing module  324  receives the notification. As described before, the notification comprises the message digest and the message ID. 
     Step  502 : the reservation buffer managing module  324  compares the message ID in the notification received and the message ID stored in the reservation buffer managing module  324 . If the comparison does not yield any match, a negative confirmation will be sent to the reservation buffer managing module  314  (step  508 ). 
     Step  504 : if the comparison yields a match, compare the message digest in the notification received and the message digest stored in the reservation buffer managing module  324 . If the comparison does not yield any match, a negative confirmation will be sent back to the reservation buffer managing module  314  (step  508 ). Then, the reservation buffer managing module  324  simply discards message data stored in the packet cache buffer  326  and indicated by the same message ID. Furthermore, after the reservation buffer managing module  314  has received the negative confirmation, the whole message is sent to the transaction backup server  320  and stored therein. In doing so, an embodiment of the present invention ensures that message data will be kept securely, even in the worst situation, such as timeout. 
     Step  506 : if the comparison yields a match, the packet cache buffer  326  will directly copy the input message  302  stored in the packet cache buffer  326  to the physical storage  328 , such as a hard disk drive or a RAID, and send an affirmative confirmation back to the reservation buffer managing module  314  (step  510 ). 
     As described before, the present invention is not limited to the environment of the switch illustrated with the aforesaid embodiments. In fact, the environment of a hub applies to the present invention as well. In the environment of a hub, a message packet is replicated and sent to all devices connected with the hub. In the environment of the exchanger, a message packet is sent to a related port with authority. Today, most switches are characterized by port mapping whereby a message packet is replicated at a port and sent to another port preconfigured. 
     The foregoing preferred embodiments are provided to illustrate and disclose the technical features of the present invention, and are not intended to be restrictive of the scope of the present invention. Hence, all equivalent variations or modifications made to the foregoing embodiments without departing from the spirit embodied in the disclosure of the present invention should fall within the scope of the present invention as set forth in the appended claims.