JP2013239939A - Mail system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve stable service by avoiding congestion of a mail gateway and/or a mail system even when external conditions such as mail profiles and so on are changed, and to facilitate the estimation of the performance of the mail gateway.SOLUTION: A mail gateway monitors plural pieces of information in the internal processing of a program, and when the monitored information exceeds a threshold, the mail gateway determines the degree of influence on congestion for each mail received by the mail gateway, and preferentially regulates the processing of mails having a higher degree of the influence on the congestion. In addition, it visualizes the information on the internal processing of the program, which could not be conventionally monitored from the outside a server, and associates each processing to perform analysis and display.

Description

  The subject matter disclosed in this specification relates to a technology of a mail gateway constituting a mail system.

  With the spread of mobile phone e-mail (hereinafter referred to as e-mail), the e-mail service of a company that provides communication services for mobile phones and mobile terminals (hereinafter referred to as mobile phones) (hereinafter referred to as mobile communication carriers) The provided system (hereinafter referred to as mail system) handles a large amount of mail. Hereinafter, an example of a mail system of a mobile communication carrier will be described.

  A mail system of a mobile communication carrier performs processing for relaying mail received from a mobile phone or the Internet to a destination, processing for converting mail character codes, attached images, etc., authentication processing, billing processing, etc. Delivered. The above processing is realized by a server device (hereinafter referred to as a server) called a mail gateway (mail server, mail relay device, mail transfer server, mail delivery server, etc.) installed in a mobile communication carrier.

  At the same time, the mail gateway is responsible for congestion control of the mail gateway itself and the entire mail system in order to realize stable operation of the entire mail system. As an example of congestion control performed by the mail gateway, there is a method disclosed in Patent Document 1. In Patent Document 1, the number of mail processes per unit time of the mail gateway is measured, and when the number of processes exceeds a predetermined threshold, the mail gateway regulates mail reception (paragraphs 0016 and 0017). The threshold value and the reception restriction method can be set in advance by the operator, and the operator can restrict the reception of mail according to the congestion state by setting a plurality of threshold values (paragraphs 0025, 0078, FIG. 5). As a result, even if a large amount of mail traffic exceeding the mail gateway itself or the processing capacity of the mail system occurs, the mail gateway regulates the inflow of mail and realizes stable operation (paragraph 0028).

Patent No. 3756331

  In recent years, traffic flowing into carrier systems has been increasing due to the spread of smartphones and the like, and mobile carriers are frequently changing and adding systems. In the background as described above, the mail gateway has the following two problems.

  The first problem is to realize stable operation of the system even if a large amount of mail traffic exceeding the processing capacity occurs as described above. However, in the method of setting the threshold of reception restriction after setting the processing status of the server in advance as in Patent Document 1, if the processing status of the server set in advance differs from the processing status in the real system, the mail gateway There is a problem that the congestion control of the system does not function sufficiently or the optimum processing performance cannot be maintained.

  To set the mail gateway threshold, the following work is required. First, conditions (processing status) such as the size of the mail, the number of destinations, the content of the mail profile and the connection pattern from the mobile phone are determined. Next, a load test is performed to apply mail traffic of various loads under the determined conditions, and a threshold value at which the mail gateway or mail system can be stably operated without being congested is determined. The above threshold is a value obtained by subtracting the margin from the maximum number of mail processes per unit time of the mail gateway or mail system (hereinafter referred to as limit processing performance), or a value obtained by multiplying the limit processing performance by a factor of margin ratio. decide.

  In an actual mail system, when the mail size is larger than expected or when the number of recipients increases, the threshold and the actual limit processing performance deviate, which may prevent stable operation. The operator must perform a series of operations for determining the threshold value and set the threshold value again. These changes in conditions occur not only due to changes on the mobile phone or user side, but also on the system side of the mobile communication carrier such as service expansion or system configuration change.

  The second problem is that it is difficult to estimate the number of units to be added (sizing) in the environment where the preconditions are likely to change as described above when adding to avoid congestion of the mail gateway. In general, mail gateway sizing is often a clear indicator from the outside of the mail gateway, such as the number of mail processes, CPU utilization, and memory usage. However, it is difficult to estimate the performance of a mail gateway in an environment where a number of preconditions change.

  That is, there is a need for a technique that can solve the above two problems in a mail system of a mobile phone carrier.

  In this specification, the mail gateway monitors information on a plurality of program internal processes, and automatically or manually sets a threshold value for the above information from the mail gateway or the outside, and avoids congestion by regulating when the threshold value is exceeded. Even if the preconditions such as the mail profile change due to the method and the method that determines the impact on congestion for each mail received by the mail gateway and preferentially regulates the processing of mail with high impact on congestion A technique for stably operating a mail gateway and / or a mail system is disclosed. In addition, the mail gateway discloses a technique that makes it easy to estimate the performance of the mail gateway by visualizing internal processing of the program that could not be monitored from the outside of the server, analyzing each related process, and displaying it. .

  The disclosed mail system has a mail gateway. The mail gateway acquires the internal processing time and status inside the program, information including exclusive information, information on the disk device and network I / O output, communication information with an external server, etc., and outputs them to the operation management terminal. The mail gateway monitors the acquired information or a combination of the above information and determines whether to start the regulation. The mail gateway performs not only mail reception restriction such as SMTP (Simple Mail Transfer Protocol) but also mail transmission restriction and command relay restriction in a protocol for operating a mailbox such as IMAP (Internet Message Access Protocol). The processing that the mail gateway performs at the time of regulation differs depending on the information acquired and monitored.

  When the regulation starts, the mail gateway changes the processing according to the content and situation of the mail. Unlike Patent Document 1, it preferentially regulates the mail processing, the number of addresses, the size of the part to be analyzed, the content of the command for sending and receiving mail, and the processing load applied to the mail gateway. To do. However, in order to prevent the situation where mail with heavy processing load is not sent at all, the mail gateway sets the mail classification (hereinafter referred to as mail class) depending on the processing load and changes the probability of restriction for each mail class. . The restriction probability of a mail class with a high impact on congestion and a high processing load is set high, and the restriction rate of a mail class with a low load is set low. In addition, the mail gateway switches the mail processing of the mail class with a high processing load that is not regulated to the processing with a reduced load.

  The mail gateway program is implemented by a combination of functions (hereinafter referred to as state processing functions) that are blocked in units such as communication processing and program status, and information including internal processing time and status is the state processing. Acquired within a function or between multiple state processing functions. The operator monitors the mail gateway state processing function list and internal processing status from the operation management terminal, and dynamically changes the internal processing information to be acquired by operating the state processing function output to the operation management terminal. can do. In addition, the operator can set items to be monitored and items to be combined from the operation management terminal and dynamically apply them.

One specific aspect is a mail system including a mail gateway for sending and receiving mail,
The mail gateway has a function of acquiring information inside the program, a function of monitoring the information inside the program, a function of associating a mail gateway regulation process from the monitored information, and a function of the mail gateway from the related information. A function for starting or ending regulation, a function for grouping mail according to the effect of mail on the mail gateway and / or mail system, and a function for selecting mail processing for each mail group at the time of the regulation It is characterized by.

  Further, in the mail gateway, the function of acquiring the information inside the program is displayed in units of processing functions in which the acquired information is output to an external server or terminal and the internal processing of the program is blocked on the external server or terminal. And a function that enables automatic determination of which processing function is delayed, or an operator can easily determine, and a function that allows the operator to dynamically set the information that the operator wants to acquire for each processing function. Also good.

  According to the disclosure, it is possible to provide a mail gateway that effectively avoids congestion even if a precondition such as a mail profile changes. In addition, it becomes possible to facilitate the performance estimation of the mail gateway.

It is a block diagram which illustrates the outline system configuration in an example. 2 is a block diagram illustrating a configuration of a mail gateway 106. FIG. A display example of the operation management terminal 109 is shown. An example of each regulation sequence of the mail gateway 106 is shown. An example of a flow chart of mail reception regulation of the mail gateway 106 is shown. An example of a flow chart of mail transmission regulation of the mail gateway 106 is shown. An example of a command restriction flowchart of the mail gateway 106 is shown. An example of a flowchart of the monitoring process of the mail gateway 106 is shown.

  Hereinafter, embodiments will be described with reference to the drawings.

  FIG. 1 is a block diagram showing the system configuration of the mail system of this embodiment.

  The mail system according to the present embodiment is configured in the carrier equipment network 103, and includes a mail gateway 106, a mailbox server 107, and an operation management terminal 109.

  The communication terminal 101 is a terminal device capable of data communication such as a mobile phone terminal, a tablet, and a PC, and is connected to the mail system of the present embodiment in the carrier equipment network 103 via the wireless network 102. The wireless network 102 is a wireless network managed by a mobile phone communication carrier. The carrier facility network 103 is a network and network facility that relays communication from the wireless network 102 to the Internet 104 and the mail gateway 106. The wireless network 102 and the carrier equipment network 103 are managed by a mobile phone carrier that manages the mail gateway 106 of this embodiment.

  The mail transfer server 105 is also called an MTA (Mail Transfer Agent), is connected to the mail system of the present embodiment in the carrier equipment network 103 via the Internet 104, and transmits / receives mail to / from the mail gateway 106. The mail transfer server 105 is installed in an equipment network managed by a communication provider such as an Internet provider or another mobile phone communication carrier. The mail transfer server 105 performs a process of transmitting mail of another communication carrier that manages the mail transfer server 105 to the mail gateway 106.

  The mail gateway 106 performs processing for relaying mail received from the communication terminal 101 to the mail transfer server 105 or the mailbox server 107, processing for relaying mail received from the mail transfer server 105 to the mailbox server 107, and communication terminal 101. A process for relaying a request for operating a mailbox and a response between the server and the mailbox server 107 is performed. In the present embodiment, a sequence in which the mail transmission path is the communication terminal 101, the mail gateway 106, the mail transfer server 105, or the mailbox server 107 in order will be described as an example. Is also applicable. In this embodiment, the communication protocol is not limited. Generally, the protocol between the mail gateway 106 and the communication terminal 101 or between the mail gateway 106 and the mail transfer server 105 is SMTP, ESMTP (Extended SMTP), IMAP, MMS ( Multimedia Messaging Service).

  The mailbox server 107 performs processing for storing the mail received via the mail gateway 106 in the user's mailbox and processing for the mailbox operation request received via the mail gateway 106.

  In this embodiment, a plurality of mail gateways 106 and mailbox servers 107 are each configured as one system for load distribution.

  The operation management terminal 109 is a terminal device for monitoring and operating a mail system such as a PC or a tablet. The operation management terminal 109 is a process for displaying the status of the mail gateway 106 or the mailbox server 107, changing the settings, etc. Processing for notifying the operator of an alarm received from the gateway 106 or the mailbox server 107 is performed.

  The authentication information server 110 is a server that manages user information of mobile communication carriers. The mail gateway 106 acquires user authentication information from the authentication information server 110 when performing user authentication or the like.

  FIG. 2 shows a hardware configuration of an information processing apparatus that implements the mail gateway 106.

  The information processing apparatus that implements the mail gateway 106 includes a processor 202, a volatile memory 207, a disk 209 that is a nonvolatile storage unit, and an input / output circuit interface 203 for transmitting and receiving data to and from the carrier equipment network 103. And an internal communication line such as a bus connecting them.

  The volatile memory 207 or the disk 209 stores the mail gateway program 204 and includes a volatile storage unit 205 that stores data. The mail gateway program 204 includes various control programs for realizing processing in which the mail gateway 106 transmits and receives mail, and these control programs are executed by the processor 202.

  The mail gateway program 204 may be stored in advance in the volatile memory 207 or the disk 209, or a removable storage medium or communication medium (that is, a network or a digital signal or carrier wave propagating through the medium) not shown. Via the volatile memory 207 or the disk 209. The disk 209 further stores data such as a log output from the mail gateway program 204 and a setting file of the mail gateway program 204.

  The contents described below are realized as functions of the mail gateway 106 by executing various control programs included in the mail gateway program 204 by the processor 202.

  The volatile storage unit 205 calculates monitoring information 210 acquired and / or monitored by the mail gateway 106, restriction information 221 that defines a restriction method for avoiding congestion, and the magnitude of influence on mail congestion. Therefore, it includes mail class definition information 222, which is definition information for classifying mail, and a queue 250. The monitoring information 210 includes processing statistical information 211, lock information 212, I / O input / output information 213, session information 214, mail processing count 215, mail profile statistics 216, queue retention information 217, and process CPU information 218. Is done. The processing statistical information 211 is information including time statistics (hereinafter referred to as processing time statistics) and execution count statistics (hereinafter referred to as execution count statistics) performed by the mail gateway 106. The lock information 211 is information on exclusive processing performed by the mail gateway 106, and includes information such as the number of times the lock has been acquired, the number of times that the lock has not been acquired, the lock holding time, and the time that the lock has not been acquired. . The lock information 211 is used to determine the processing efficiency of the mail gateway 106. When the processing efficiency of the mail gateway 106 decreases due to the exclusion process, the values of the number of times the lock could not be acquired, the holding time of the lock, and the time waited without acquiring the lock increase.

  The mail gateway 106 has a plurality of types of locks, and the mail gateway 106 is composed of a plurality of processes or threads (hereinafter, in the present embodiment, the processes or threads are unified by the notation of processes). The mail gateway 106 prepares the same number of lock information 211 as the product of the number of types of locks and the number of processes in order to avoid performing exclusive processing to acquire the lock information 211. The I / 0 input / output information 213 is processing information of each I / 0 such as communication with a disk, a RAID storage device, and an external server, and includes information such as a communication time, a processing count, and a waiting processing count. . Also, the I / 0 processing information for communication with the external server includes the state of a memory area (hereinafter referred to as a transmission / reception buffer) used for transmission / reception. In general, since I / 0 input / output tends to be a performance bottleneck of the mail gateway 106, the mail gateway 106 holds I / 0 input / output information 213 for I / 0.

  The session information 214 is information on a communication session with the communication terminal 101 and the mail transfer server 105, and includes the number of sessions, a time when the session is held, a time when the session is disconnected from the communication terminal 101, and the like.

  The mail processing number 215 is the number of mails processed by the mail gateway 106 within a predetermined time. The mail profile information 216 indicates statistical information on command profiles such as mail traffic, mail transmission commands, and mailbox operations, and includes statistical information such as mail size, number of addresses, mail header and body sizes, and commands. The queue retention information 217 is information on the queue 250 held by the mail gateway 106, and includes information such as the number of emails retained in the queue 250, the number of successful transmissions, and the number of failures. The process CPU information 218 is the CPU usage rate of each process of the mail gateway 106. Information included in the monitoring information 210 can be displayed on the operation management terminal 109 in real time.

  The mail class definition information 222 is definition information for classifying mail. The mail class classifies the mail characteristics into several groups, such as the size of the mail, the number of recipients, the size of the part to be processed by the mail gateway 106, the content of the command for sending and receiving mail. is there. For example, a mail class using mail size as an index can be classified into mail sizes of 1 KB or less, 1 KB to 100 KB, and more than 100 KB. In the mail class using the command contents as an index, it can be defined by a combination condition of the type of command and information attached as an argument of the command. For example, conditions such as a command for searching a mailbox and a search range can be described. One mail class definition information 222 stores one index mail class.

  The restriction information 221 is information related to restriction that is executed when the monitoring information 210 exceeds a threshold value or changes significantly in a short time. The restriction information 221 includes one or more pieces of information of the monitoring information 210, a threshold value of the monitoring information 210 for performing the restriction, a mail class that affects the monitoring information 210, and a process at the time of restriction for each mail class. (Or function). In the restriction information 221, a plurality of combinations of mail classes and monitoring information 210 can be set. Based on the restriction information 221, the mail gateway 106 associates the mail characteristics (that is, the mail class) with the monitoring information 210 that has a large influence by processing the mail, and can select a restriction process with a high effect of avoiding congestion.

In order to reduce the mail processing load in the restriction information 221, even if no restriction is made,
Describe settings that can change processing for each mail class. Specific examples of use of the restriction information 221 will be described with reference to FIGS.

  The queue 250 is an area for storing mail received by the mail gateway 106. The mail gateway 106 holds a backup of the queue 250 on the disk 209 so that mail is not lost during processing.

  FIG. 3 is a diagram illustrating an example of a display example of the operation management terminal 109. Reference numeral 300 is a setting screen for acquiring the processing statistical information 211, and reference numeral 350 is a screen displaying the processing time statistics of the processing statistical information 211.

  The setting screen 300 shows the flow of the state processing function that constitutes the mail gateway 106, and here shows an example of mail reception processing and transmission processing. In the mail reception process flow 301, the mail gateway 106 receives a connection from the communication terminal 101 (302), the greeting process (303) performed at the start of communication with the communication terminal 101, and the communication terminal 101 is authenticated. A series of processing in mail reception such as communication processing (304) with the authentication information server 110 and mail reception processing (305) is arranged in the processing order. The mail gateway 106 acquires three types of processing time statistics for each state processing function, a series of mail reception processing 301, and a set time described later, and stores them in the corresponding processing statistical information 211.

  The operator can set where to display the processing time statistics of the state processing function. In the example of FIG. 3, “statistic A” indicates a processing time statistic from 302 to 305, and “statistic B” indicates a processing time statistic of communication 304 with the authentication information server 110. For example, when the operation management terminal 109 is realized by a tablet or the like, it can be set whether or not the processing state is acquired by touching with a finger. In addition, the execution count statistics of the processing statistical information 211 and the items of the lock information 212 can be similarly displayed and set.

  The display screen 350 is an example of a screen that displays the set processing time statistics. In addition to the example of FIG. 3, each item of the monitoring information 210 such as processing time statistics in units of state processing functions, processing time statistics of a series of mail reception processes 301, lock information 212, and the like can be displayed. In addition, it is possible to select and display only information to be compared, and to display a comparison with past processing statistical information 211 remaining in the log.

  Based on the correlation of the displayed information group, the operator can determine which process of the mail gateway 106 is delayed and what is the performance bottleneck of the mail gateway 106. Similarly, it is possible to automatically detect the cause of the delay and the performance bottleneck by setting the processing flow for determining the correlation in the mail gateway 106.

  FIG. 4 is a diagram showing an example of a restriction sequence of the mail gateway 106. As shown in FIG. The mail gateway 106 has three types of restriction functions: mail reception restriction that restricts mail reception, mail transmission restriction that restricts mail transmission, and command restriction that restricts commands such as mailbox operations. Each regulation in FIG. 4 is started after detecting that any threshold value of the monitoring information 210 is exceeded (step 401) in the processing in which the mail gateway 106 monitors the monitoring information 210 (hereinafter, monitoring processing). Details of the monitoring process are shown in FIG.

  Steps 402 to 409 show a mail reception restriction sequence. First, the communication terminal 101 connects to the mail gateway 106 to transmit mail (step 402), and the mail gateway 106 performs reception restriction determination 1 (step 403). Details of the mail reception restriction determination 1 (step 403) will be described with reference to 502 in FIG. If it is determined in step 403 that the restriction is made, the mail gateway 106 disconnects the connection with the communication terminal 101 (step 404). If it is determined that the restriction is not restricted, the mail gateway 106 continues the reception process and sends the mail from the communication terminal 101. The command and the mail text are received (step 405). Next, the mail gateway 106 performs mail reception determination 2 (step 406) from the information acquired in step 405. Details of the mail reception determination 2 (step 406) will be described with reference to 506 in FIG. If it is determined in step 406 that the restriction is made, the mail gateway 106 transmits a restriction response in such a manner that the user of the communication terminal 101 can understand the error content (step 407). If it is determined that the restriction is not restricted, the received mail is stored in the queue 250. Then, a normal response 409 is transmitted to the communication terminal 101 (step 408).

  Steps 421 to 424 show a mail transmission restriction sequence. First, the mail gateway 106 retrieves the mail stored in Step 408 from the queue 250 (Step 421). Next, the mail gateway 106 refers to the contents of the retrieved mail and makes a mail transmission restriction determination (step 422). Step 422 is processing for determining whether or not to restrict transmission based on the size of the extracted mail, the size of the area to be processed, and the processing load assumed for transmission, and details will be described with reference to FIG. If it is determined in step 422 that the mail gateway 106 is restricted, the mail gateway 106 stores the mail in the queue 250 that is retrieved after a predetermined time. If it is determined that the mail gateway 106 is not restricted, the mail gateway 106 transmits a plurality of mails to the mail transfer server 105. The process is performed and transmitted (step 424).

  The communication from step 441 to step 446 is a mailbox operation command of the communication terminal 101 and its response. Mailbox operations include operations such as IMAP, POP, and MMS, such as the communication terminal 101 logging in to its own mailbox, retrieving mail, changing the status such as marking a mail as read, and obtaining a list of mailboxes. Often implemented with protocols. Steps 441 to 446 show examples of command relay restriction in the sequence in which the communication terminal 101 acquires mail from the mailbox server 107.

  First, the mail gateway 106 receives a command request for acquiring mail from the communication terminal 101 (step 441), and the mail gateway 106 makes a command restriction determination (step 443). Step 443 is a restriction determination process for avoiding congestion of the mail gateway 106 and the mailbox server 107, and details will be described with reference to FIG. If it is determined to be restricted in step 443, a restriction response is transmitted (step 444). Otherwise, a mail acquisition request is transmitted to the mailbox 107 (step 445). Next, the mail gateway 106 acquires the mail (step 446) and transmits it to the communication terminal 101 (step 447).

  FIG. 5 is a diagram showing a flow of the mail reception restriction determination function of the mail gateway 106. FIG. 5 shows a flow for determining whether or not to restrict when the mail gateway 106 receives mail from the communication terminal 101, and selecting a restriction method. Step 502 corresponds to 403 in FIG. 4, and step 506 corresponds to 406 in FIG. The flow shown in FIG. 5 is executed as a part of the mail gateway program 204.

  There are two types of mail reception restriction determination in FIG. 5, a connection disconnection method and a restriction response method. The restriction response is a means for sending a response to the mail or the command for sending the mail received from the mail gateway 106 communication terminal 101, including a message indicating that the restriction is made, to the user operating the communication terminal 101. Can tell the situation. On the other hand, the disconnection is means for the mail gateway 106 to disconnect the connection with the communication terminal 101, and it is not known from the communication terminal 101 whether the connection has been disconnected due to restrictions. Therefore, it is better for the mail gateway 106 to select a restriction response in the reception restriction. However, depending on the situation of the mail gateway 106, it may be more effective for avoiding congestion to disconnect the connection in order to avoid congestion. In FIG. 5, the mail gateway 106 executes the flow based on the above preconditions.

  First, the mail gateway 106 receives a connection from the communication terminal 101 (step 501), and performs the following determination process (step 502).

(1) Whether the number of sessions with the communication terminal 101 exceeds the threshold value (2) The processing time statistics of the reception processing of the mail gateway 106 is the time for disconnecting the connection from the communication terminal 101 side during the mail reception processing If the above determination condition is met, the mail gateway 106 disconnects the connection (step 503). Proceed (step 504). (1) is performed to suppress an increase in the number of sessions and an increase in the load on the mail gateway 106, the wireless network 102, and the carrier equipment network 103. (2) is performed to reduce retransmission of mail by the communication terminal 101. When the mail gateway 106 approaches a congestion state, the reception processing time of the mail gateway 106 becomes longer. If the situation further deteriorates, a situation occurs in which the user handling the communication terminal 101 is disconnected before the mail gateway 106 completes the reception process. There is a case of resending. At this time, the mail gateway 106 performs processing corresponding to the retransmission by the communication terminal 101, thereby further increasing the load on the mail gateway 106. Therefore, the mail gateway 106 makes the determination (2) in order to reduce retransmission of the mail.

  After receiving the mail (step 504), the mail gateway 106 receives the mail size, the number of recipients, the size of the mail header or the mail body to be analyzed, and the address that needs to be converted (image transfer server) 105), and the mail class is determined according to the mail class definition information 222 (step 505). Next, the mail gateway 106 searches the restriction information 221 for an item corresponding to the determined mail class, and determines whether or not to restrict (step 506). In step 506, the rate of restriction is set to increase as the load on the mail gateway 106 or the mail system increases. However, the load on the mail system is very large, and the mail restriction rate is not set to zero. The reason for not setting the mail restriction rate to zero is to prevent mail that cannot always be transmitted from the communication terminal 101 from being generated. If one mail is determined to be in a plurality of mail classes in step 505, the mail gateway 106 determines in step 506 whether to regulate for each of the plurality of mail classes.

  Examples of the mail class used in the restriction determination in step 506 include mail size, number of mail destinations, analysis size such as character conversion and header analysis. As for the mail size, the larger the size, the greater the load on the disk I / O (I / 0 input / output information 213). Similarly, with regard to the number of mail destinations, when the mail gateway 106 internally copies and processes the addresses, the load on the disk I / O (I / 0 input / output information 213) increases as the number of addresses increases. . For processing such as character conversion and header analysis, when the load of the CPU information 218 of the process that performs the processing is increased, the efficiency of the exclusive processing (lock information 212) is deteriorated, or the processing statistical information 211 of the processing is delayed. there is a possibility. It is also possible to set a mail class that combines a plurality of information such as the product of the mail size and the number of mail addresses. As described above, the operator can dynamically set the monitoring information 210 correlated with the mail class in the restriction information 221.

  If it is determined in step 506 that there is a restriction, the mail gateway 106 transmits a restriction response (step 507).

  In step 509, the mail gateway 106 refers to the restriction information 221, determines whether the mail class is a target for changing the reception process, and proceeds to step 510 if it is a target for changing the process. In step 510, the mail gateway 106 performs a reception process that is partially modified to reduce the load on the mail gateway 106 or the mail system, instead of the normal reception process. As an example of steps 509 and 510, there is a mail class flow in which the product of the mail size and the number of mail addresses exceeds a threshold. If the mail gateway 106 is copying and processing mail for the destination, the mail gateway 106 stores the copied mail for the destination in the queue 250 at a time, but the product of the mail size and the number of mail destinations is large. As the time goes on, the load on the disk I / O (I / 0 input / output information 213) increases. Therefore, if the mail is determined to be a mail class in which the product of the mail size and the number of mail addresses exceeds the threshold (step 509), the mail gateway 106 performs processing to reduce the load on the disk I / O. Change (step 510). The processing to reduce the load is a method in which the mail gateway 106 divides the mail copied for the destination into a plurality of times, and waits for a certain time after storing the mail once and then stores the next mail. is there. The mail gateway 106 continues the mail reception process after passing through step 509 or step 510.

  FIG. 6 is a diagram showing a flow of the mail transmission restriction determination function of the mail gateway 106. FIG. 6 shows a flow of determining whether to restrict and selecting a restriction method when the mail gateway 106 transmits mail to the mail transfer server 105 (see FIG. 4 for details). The flow shown in FIG. 6 is executed as a part of the mail gateway program 204, and mainly converts a mail character or the like according to a mail sending process (hereinafter referred to as a sending process) and a mail destination. It is executed by a process (hereinafter referred to as a conversion process). These processes are registered as CPU information 218 of the monitoring information 210.

  First, the mail gateway 106 acquires mail from the queue 250 (step 601), and determines whether the monitoring information 210 related to transmission processing exceeds a threshold value (step 603). Examples of monitoring information 210 in step 603 include conversion process CPU information 218, processing time (processing statistical information 211) delay, and exclusive processing (lock information 212). These monitoring information 210 includes processing performed by the conversion process. Related. Since the conversion process converts the header of the email and the characters included in the email body, if the part to be converted such as the email header or body is large, the CPU information 218 of the conversion process rises and the processing time ( There is a characteristic that the delay of the processing statistical information 211) and the efficiency of the exclusive processing (lock information 212) deteriorate. Therefore, the mail gateway 106 performs a regulation method using the above characteristics in steps 604 to 607.

  In step 603, if the monitoring information 210 exceeds the threshold value, the process proceeds to step 604. If it is determined not to restrict, the process proceeds to step 607. In step 604, the mail gateway 106 acquires the mail size to be processed in the conversion process and the size to be analyzed, and determines the mail class according to the mail class definition information 222 for the mail. Next, the mail gateway 106 searches the restriction information 221 for an item corresponding to the determined mail class, and determines whether to restrict (step 605). As in step 506, step 605 is set such that the greater the load on the monitoring information 210, the higher the probability of being restricted. If the restriction is determined in step 605, the mail gateway 106 stores the mail in the queue 250 taken out after a predetermined time (step 606), and if it is determined not to restrict, the mail transmission process is continued (step 607). In step 606, the mail gateway 106 may change the time stored in the queue 250 for each mail class.

  FIG. 7 is a diagram showing a flow of the command restriction determination function of the mail gateway 106. FIG. 7 shows a flow of determining whether or not to restrict and selecting a restriction method when the mail gateway 106 receives a request command for mailbox operation from the communication terminal 101 (see FIG. 4 for details). The flow shown in FIG. 7 is executed as a part of the mail gateway program 204.

  First, the mail gateway 106 determines whether the monitoring time 210 such as the response time (processing statistical information 211) of the mailbox server 107 and the CPU information 218 of the process performing the command processing exceeds a threshold (step 701). In step 701, if the monitoring information 210 exceeds the threshold value, the process proceeds to step 702, and if it is determined not to restrict, the process proceeds to step 707. In step 702, the mail gateway 106 determines a mail class according to the mail class definition information 222. The mail class definition information 222 used in step 702 is classified with the command type as an index, and does not necessarily include the mail characteristics and the like. In step 703, the mail gateway 106 determines whether the load imposed on the monitoring information 201 by the command processing is high according to the mail class and the restriction information 221, and determines whether to perform restriction.

  Specific examples of commands (email class) that perform the restriction in step 703 include a search request for a high-load mailbox, a request to acquire a large mail, a request to acquire a large amount of mail at a time, and the like. . If it is determined in step 703 that a restriction is made, a restriction response is transmitted as a response to the mail gateway 106 command (step 704). If it is determined that no restriction is made, the process proceeds to step 705. In step 705, the mail gateway 106 determines whether the number of reception requests within the set time exceeds the threshold value. As an example of step 705, there is a request for confirming whether new mail has arrived in the user's mailbox in the mailbox server 107 (hereinafter referred to as an update confirmation request). Currently, since there is a communication terminal 101 that frequently and automatically transmits an update confirmation request in a mobile communication carrier, a response indicating that there is no update is transmitted in step 705 in response to an unnecessary update confirmation request. Some communication terminals 101 frequently access a mailbox in order to check whether new mail has arrived in the mailbox. Frequent access to the mailbox increases the load on the mail gateway 106 and the mailbox server 107. Therefore, in step 705, if it is determined that the user has a lot of mailbox access, the restriction and the response from the mail gateway 106 to the mailbox server 107 are not relayed to the mailbox server 107, and a response indicating that there is no new mail is created and transmitted. (Step 706). If it is determined in step 705 that no restriction is made, the command processing is continued (step 707).

  Note that the flows shown in FIGS. 5 to 7 are merely examples of restriction determination. By changing the setting of the mail gateway 106 by the operator, it is possible to freely change the judgment conditions for each regulation, the contents of the regulation processing, and the order of each judgment. The above setting is realized by the operator setting a determination condition or the like on the operation management terminal 109 or changing the setting file of the mail gateway 106. By the above setting change, the operator can reflect the information obtained from the operation experience of the mail gateway 106, and the effect of avoiding congestion can be enhanced.

  FIG. 8 is a diagram showing a flow of the monitoring processing function of the mail gateway 106. FIG. 8 shows a flow until the mail gateway 106 monitors the monitoring information 210 and validates the restriction process described in the restriction information 221 when any of the pieces of monitoring information exceeds a threshold value. The flow shown in FIG. 8 is repeatedly executed as part of the mail gateway program 204, for example, periodically.

  First, the mail gateway 106 checks each piece of information in the monitoring information 210 (step 801), and if any of the information exceeds the threshold or has a large change in a short time, it is described in the restriction information 221. The restriction processing function is activated (step 803). The function of restriction processing in step 803 indicates the restriction function of mail reception restriction, mail transmission restriction, or command restriction, and the activation of the restriction function refers to the restriction determination process (FIGS. 5 to 7). Indicates to start. If there is no problem in the monitoring information 210 in step 801, the restriction function is invalidated, that is, the restriction state is released (step 807).

  Next, in step 804, the mail gateway 106 determines the effect of the restriction function, and if there is an effect, continues the restriction (step 806), and if not, raises an alarm to the operator or the operation management terminal 109 (step 806). Step 805).

  Next, the mail gateway 106 identifies the cause of the processing delay in steps 811 to 813. The mail gateway 106 acquires processing time statistics, execution count statistics, and lock information 212 of processing statistical information 211 such as mail reception processing, mail transmission processing, command relay processing, etc., and any of the processing exceeds a threshold. (Step 811). If there is a process that exceeds the threshold value in step 811, the correlated part is extracted by referring to the processing information of the state processing function of the process (step 812), and the cause of delay or the bottleneck part is determined by the operator. Or displayed on the operation management terminal 109 (step 813). By step 813, the operator can facilitate performance bottleneck analysis and performance estimation of the mail gateway 106.

  Next, a second embodiment will be described. The algorithm for extracting the correlation can be changed by the operator setting a determination condition or the like on the operation management terminal 109 or by changing the setting file of the mail gateway 106.

  The second embodiment is a method of avoiding congestion by increasing the resources related to the monitoring information 210 exceeding the threshold value instead of the regulation function performed by the first embodiment. The second embodiment can be realized by replacing the regulation function performed by the first embodiment with a function for increasing resources. Differences between the second embodiment and the first embodiment will be described below with reference to the drawings. The second embodiment has the configuration shown in FIG. 1 and has the display function of the operation management terminal 109 shown in FIG. In the second embodiment, the regulation function shown in FIGS. 4 to 7 is not used.

  In FIG. 2, instead of the restriction function stored in the restriction information 221 in the first embodiment, the second embodiment stores a function for increasing resources.

  In steps 803 to 807 of FIG. 8, the restriction function is replaced with a function for increasing resources. For example, if the threshold value of the CPU information 218 of a specific process is exceeded (step 801) and the CPU of the entire server has room, the mail gateway 106 increases the number of the specific processes (step 803). If the I / O input / output information 213 of the disk device exceeds the threshold (step 801), the mail gateway 106 mounts an additional disk area (step 803). If the I / O input / output information 213 of the other server exceeds the threshold (step 801), another server can be started using the mail gateway 106 as a trigger (step 803). In steps 804 to 807, the flow is the same only by replacing the restriction function with a function for increasing resources.

  In addition, in an actual mail system, there are servers that perform various processes such as a server that performs accounting processing in addition to the server groups shown in the first and second embodiments. It is also possible to apply to a method for avoiding congestion.

  101: communication terminal, 103: carrier equipment network, 105: mail transfer server, 106: mail gateway 107: mailbox server, 109: operation management terminal.

Claims (13)

A mail system including a mail gateway that receives mail from a mail transmission device and delivers mail to the mail reception device,
The mail gateway is
A function to acquire information in the program internal processing,
A function of monitoring the information;
A function of associating a mail gateway regulation process from the monitored information;
A function to start or end the regulation of the mail gateway from the related information;
The ability to group emails according to the impact of received emails on email gateways and / or email systems;
A mail system having a function of selecting mail processing at the time of restriction for each mail group. The mail system according to claim 1,
The mail gateway is
A function to obtain statistical time of communication maintenance time when mail reception from a communication terminal fails,
A function of acquiring a statistical time required for the reception processing of the mail gateway;
A function of comparing the two types of statistical information;
A mail system comprising: a function of disconnecting a connection when the reception processing time exceeds the communication maintenance time. The mail system according to claim 1 or 2,
The mail gateway is
The ability to analyze the characteristics of received emails and / or commands;
A function of associating and managing received mail and / or command characteristics and monitoring information of the mail system;
A mail system comprising: a function for determining mail reception restrictions based on characteristics of received mail. The mail system according to claim 3,
The mail gateway is
A mail system having a function of increasing the probability of restricting reception as the influence of received mail on a mail gateway and / or mail system increases. The mail system according to claim 3,
The mail gateway is
A mail system comprising a function for changing a processing method of received mail to a process for reducing the influence when it is determined that the received mail has a large influence on the mail gateway and / or the mail system. The mail system according to claim 1,
The mail gateway is
A function of managing the characteristics of the mail to be transmitted in association with the monitoring information of the mail system;
A function for determining whether to restrict transmission of mail according to the characteristics of the transmitted mail when the monitoring information of the mail system exceeds a threshold;
A mail system comprising: a function of delaying transmission of the mail for a specified time when it is determined that the restriction is performed in the determination. The mail system according to claim 1,
The mail gateway is
A function of managing the characteristics of the received command in association with the monitoring information of the mail system;
A function for determining whether to restrict the reception of a command according to the characteristics of a command received when the monitoring information of the mail system exceeds a threshold;
And a function of transmitting a restriction response to the command when it is determined that the restriction is performed in the determination. The mail system according to claim 1,
The mail gateway is
A function of managing the characteristics of the received command in association with the monitoring information of the mail system;
A function of transmitting a response indicating that there is no update to the command when receiving a command response for confirming the update of the mail gateway when the monitoring information of the mail system exceeds a threshold value. Characteristic mail system. The mail system according to claim 1,
The mail gateway is
If the monitoring information of the mail system has exceeded a threshold value, or if the monitoring information of the mail system has changed significantly in a short time, one or more regulation functions related to the monitoring information state are enabled. A mail system characterized by having a function. A mail system including a mail gateway that receives mail from a mail transmission device and delivers mail to the mail reception device,
The mail gateway is
It is composed of a function group that is blocked in units such as communication processing and the internal state of the program, and a function for displaying the function group on an operation terminal, etc.
A function for selecting information to be displayed by selecting the function group;
A function to acquire a plurality of information in the program internal processing;
A mail system comprising a function of displaying the plurality of pieces of information on an operation terminal or the like. The mail system according to claim 10, wherein
The mail gateway is
A function of comparing information acquired in the function group and the processing group;
And a function of extracting correlated information as a result of the comparison. The mail system according to claim 1, wherein
The mail gateway is
In the exclusive process used by the process or thread in the mail gateway, a function of acquiring exclusive process information including information on the number of times the exclusive process was performed for each of a plurality of locks and / or information on the time of the exclusive process;
And a function of displaying the exclusive information on an operation terminal. The mail system according to claim 1,
The mail gateway is
A function of increasing one or a plurality of resources related to the monitoring information state when the monitoring information of the mail system has exceeded a threshold value or when the monitoring information of the mail system has changed significantly in a short time; A mail system characterized by comprising.

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