JP2732688B2 - Management host switching control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Overview] Management in a system in which a plurality of host processing devices share a communication control processing device and a management host that manages communication resources under the communication control processing device is defined The host switching control method has a function to enable the management host to declare the management host when another failure occurs in the management host. Notification process from each host processing device to the communication control processing device, and when the communication control processing device receives a declaration of a management host, the request is stacked, and the management host is notified to the host processing device that declared earlier. The process of notifying permission and, if the management host fails, another host that has declared the management host next from the stack. And a process of newly notifying of a management host permission, wherein the management host is automatically switched when the management host fails.

[Industrial applications]

The present invention relates to a management host switching control method in a system in which a plurality of host processing devices share a communication control processing device, and in which a management host for managing communication resources under the communication control processing device is defined.

[Conventional technology]

FIG. 3 shows an example of the prior art, and FIG. 4 shows an example of the conventional command sequence.

As shown in FIG. 3 (a), a plurality of host processors 10
When A and 10B share one communication control processor (CCP) 11 and use the same communication line 13 under the control of the communication control processor 11, conventional control is performed as follows, for example.

One host determined in advance as a management host, for example, the host processor 10A activates the communication line 13 or the terminal 20. The communication control processing device 11 stores the host processing device 10A as a management host.

When a session establishment request is sent from the terminal 20, the communication control processing device 11 notifies the host processing device 10A managing the terminal 20 of a session establishment request message.

The host processing device 10A, which is the management host, determines the communication partner requested by the terminal 20 by looking at the message. For example, if it is a program that runs on the host processing device 10B, the host processing device 10A Notify.

The host processor 10B that has received the notification establishes a logical session and performs data communication with the terminal 20.

As shown in FIG. 3B, if the host processing device 10A, which is the management host, goes down due to a failure, the request from the terminal 20 cannot be accepted.

Therefore, in the prior art, when the host processing device 10A fails, an operator intervenes and the host processing device 10B
Then, a terminal management notification as shown in FIG. Thereafter, the communication control processor 11 stores that the management host of the terminal 20 is the host processor 10B, and notifies the host processor 10B of a session establishment request from the terminal 20.

FIG. 4 shows a command sequence between the host processing device and the communication control processing device. As in the example of FIG. 3, it is assumed that the management host is the host A and the partner terminal communicates with the host B.

When the host A, which is the management host, is started, the host A notifies the partner terminal that the administrator of the terminal is the host A by using the ACTPU / ACTLU command. Note that these commands are commands for activating the physical unit / logical unit formed by the communication resources. + Resp
Is the response to it.

When a communication request to the host B occurs at the partner terminal, the partner terminal transmits a session establishment request message to the host A because the management host is the host A.

The host A determines that the session establishment request is for the host B, and notifies the host B of the request for the session establishment by a CDINIT command. CDINIT
The command is a communication command between the hosts.

The host B sends a session start message (BIND command) to the partner terminal. Thereafter, data communication is performed between the host B and the partner terminal.

If a failure occurs on host A, which is the management host,
In order to switch the management host from host A to host B according to an instruction from the operator, ACTP to the partner terminal
Issue U / ACTLU command.

[Problems to be solved by the invention]

Conventionally, when a plurality of host processing devices share a communication control processing device and use communication resources such as a communication line under the communication control processing device, the management host is determined in advance and the management host is determined via the management host. Thus, a logical session is established with a communication partner and communication is performed.

Therefore, when a failure occurs in the management host, another host processing device cannot establish a new logical session. In order to make this possible, an operation for instructing another host processing device to newly become a management host is required, and there has been a problem that communication cannot be quickly resumed.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problem and to enable, when a failure occurs in a management host, communication to be promptly continued by another host processing device.

[Means for solving the problem]

 FIG. 1 is a diagram illustrating the principle of the present invention.

In FIG. 1, reference numerals 10A and 10B denote host processing units having a CPU and a memory for data processing, 11 a communication control processing unit (CCP) for controlling communication via a communication line, and 12 a control host declaration information. Represents the stack to store.

The host processing devices 10A and 10B share the communication control processing device 11.

When the system of the host processor 10A starts up, the host processor 10A receives a session establishment request message from a terminal and declares a management host for notifying the request to a communication partner by a process P1. Similarly, the host processor 10B declares the management host by the process P2 when the own system starts up.

When receiving the declaration of the management host, the communication control processor 11 sets the request in the stack 12 by the process P3,
An earlier declared host processor, for example, host processor 10
Notify A of management host permission.

Thereby, the host processing device 10A thereafter operates as the management host.

When the host processing device 10A serving as the management host fails, the communication control processing device 11 causes the stack 12
Then, the host processing device 10B declaring the management host is selected next to the host processing device 10A, and the host processing device 10B is newly notified of the management host permission.

As a result, when the management host fails, the management host is automatically switched without the intervention of an operator or the like.

[Action]

According to the present invention, the communication control processor 11 stacks and stores the declarations of all the management hosts, and notifies the permission of a new management host when a failure occurs in the management host, so that the communication can be automatically continued. Become. It should be noted that the information on the host processing device that has been given permission as the management host may be stored separately from the stack 12 shown in FIG.

〔Example〕

FIG. 2 shows an example of a command sequence according to an embodiment of the present invention.

In FIG. 2, the sequence shown by the thick solid line is a part different from the conventional technique described in FIG. Host A
The description will be made on the assumption that the two host processing apparatuses, namely, the host B and the host B share a communication control processing apparatus, and the partner terminal communicates with the host B.

When the system A starts up, prior to issuing the ACTPU / ACTLU command for notifying that the other terminal is owned, the host A makes a declaration that it can be a management host. This command is called the ACTDTE command.

The communication control processing device returns a + resp response, stacks the declaration of the management host, and gives the permission of the management host to the host A because this declaration is the first declaration.

When the host A obtains the permission of the management host, it notifies the partner terminal that the terminal administrator is the host A by ACT.
Performed by PU / ACTLU command.

When a communication request to the host B occurs at the partner terminal, the partner terminal transmits a session establishment request message to the host A because the management host is the host A.

The host A determines that the session establishment request is for the host B, and notifies the host B of the request for the session establishment by a CDINIT command.

The host B sends a session start message (BIND command) to the partner terminal. Thereafter, data communication is performed between the host B and the partner terminal.

Although the description is delayed in time, the host B that has started up after the delay of the host A issues an ACTDTE command and declares a management host, similarly to the host A. The communication control processor stacks this declaration. However, since the permission of the management host has already been given to host A, host B
Do not grant this permission.

Thereafter, it is assumed that a failure has occurred in the host A. The host failure may be detected directly by the communication control processing device, or may be detected by notification from the host processing device or the monitoring device. Various methods have been known for this failure detection, and a description thereof will be omitted.

When recognizing the failure of the host A, the communication control processing device extracts the stack information. Since it is known that the host B has declared the management host next to the host A, permission of the management host is given to the host B. This is done automatically without operator intervention. When receiving the permission, the host B notifies that the owner of the partner terminal is the host B.

Thereafter, the host B becomes the management host, and the session establishment request message from the partner terminal is notified to the host B.

Although an example has been described in which two host processing devices share the communication control processing device, control can be similarly performed with three or more host processing devices.

〔The invention's effect〕

As described above, according to the present invention, in the event of a host failure, it is possible to automatically switch to the substitute host without performing an operation for switching the management host, and the communication is not stopped.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining the principle of the present invention, FIG. 2 is an example of a command sequence according to an embodiment of the present invention, FIG. 3 is an example of a prior art, and FIG. 4 is an example of a conventional command sequence. In the figure, 10A and 10B are host processing devices, 11 is a communication control processing device,
12 indicates a stack, 13 indicates a communication line, and P1 to P4 indicate processing steps.

Claims (1)

(57) [Claims] In a system in which a plurality of host processing devices (10A, 10B) share a communication control processing device (11), a message from a terminal requesting a logical connection with a communication partner is received and the request is distributed. (P1, P2) in which the host processor that has the function as a management host notifies the communication control processor of the declaration of the management host to perform. , Stacking the request and notifying the host processing device that declared earlier of the management host permission (P3)
If the host processing device that has become the management host fails, the communication control processing device selects another host processing device that has declared the management host next from the stack, and A new management host permission notification step (P4), wherein the management host is automatically switched when the management host fails.