JPS6116353A - Ncp breakdown preventing system of communication control processor - Google Patents

Abstract

PURPOSE:To minimize the service stop range when a software trouble occurs in a communication control program (NCP), by inhibiting the use of only the resource of task of a control routine which encounters logical contradiction of software. CONSTITUTION:If the task of a background processing routine L5 detects logical contradiction of software by a control table 20 during processing execution, the routine L5 reports this detection to a supervisor L4. The supervisor L4 terminates forcibly the task of the routine L5 and inhibits the use of resources which the routine L5 uses. An operator indicates dynamic dumping to the NCP, and a communication access method program (VTAM)13 commands it to an NCP17. After completion of dumping, the VTAM13 executes forced deactivation to reset resources, which are causes of troubles, to the initial state by the indication of the operator for the purpose of synchronizing the VTAM and the NCP with each other. The VTAM13 executes activation to activate resources into the usable state by the indication of the operator, and the NCP work using resources is restarted.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a technology for handling failures in an information processing system, particularly when a software failure occurs in a communication control program NCP in a communication control processing device for network control. , minimize the range of service outage and NCP
Concerning methods for preventing towning.

[Conventional technology]

FIG. 2 is an overview 1 of a typical example of an information processing system to which the present invention is directed. ] in the figure is a post processor, 2
is an application program, 3 is a communication access method program v=
4 represents a communication control processing unit CCP, 5 represents a communication control program NCP, 6 represents a communication line, and 7 represents a terminal.

Telecommunications Access Act Program VTAM (hereinafter referred to as ■TA
M) 3 is a communication control processing unit CCP (hereinafter referred to as c
The communication control program NCP (hereinafter abbreviated as NCP) 5 in the application program 2 and the terminal 7 is efficiently controlled, and at the same time, network management, RAS, etc. It performs advanced and diverse service functions related to.

The NCP 5 consists of a large number of control routines, and as shown in the figure, it is hierarchized into functional levels from, for example, to L5. In this example, the main contents of each functional level are as follows.

LI Nihad Error City Ul Wholesale Rechin L2;
Interrupt control routine L, which controls transmission and reception in character units: Routine L3', which executes transmission control procedures:
Channel Control Routine L4 - Supervisor L: Hack Ground Processing Routine By the way, in the conventional CCP 4, when some kind of software failure occurs in the NCP, the NCP goes down and all service functions of the NCP are stopped. This is the same as the shutdown that occurs when a hardware failure occurs.

For example, if a logical contradiction is detected while the L5 hackground processing routine is executing the process, then
``Notify the supervisor of L, Hashi, to that effect using a macro, and the supervisor will cause the NCP to go down after taking necessary measures.

In general, logical contradictions in software depend on the timing of processing, appear as rare cases, and are often not repeatable. For example, when the L5 processing routine refers to the control table used as a resource, the pointer's address is? If you encounter a response error or an error where something that should not exist appears to exist, a logical contradiction will be detected immediately and the NCP will go down, but then the I
If you start over from PI7, it often does not reproduce.

[Problem that the invention seeks to solve]

When a logical contradiction is detected in the resources used by a control routine in NCP, other unrelated control routines will also be stopped, resulting in a down state, which will have a large impact and make it difficult to restart the service. It took a long time to complete the process, which caused problems in system operation.

[Means for solving problems]

In the present invention, when a software failure occurs in the NCP,
In order to minimize the extent of service outage and avoid a complete outage, what should we do when we encounter a logical contradiction in the software? This method disables the use of only the task resources of the 1tl routine, and its means include a host processor equipped with a communication access method program TAM, and a communication control program LNCP that is linked with the communication access method program VTAM of the host processor. In an information processing system having a communication control processing device, when the communication system 9 wholesale program NCP detects a logical contradiction in the software while a certain control fill routine task included in its own program is running, Forcibly terminate the task and prohibit the use of the resources used by the task.'' - Written access method program VTAM
In accordance with the Telecommunications Access Act Progera 1, VTAM:
This system is characterized in that it instructs the communication control program NCP to execute a dynamic dump, and also initializes resources that were previously prohibited from use so that they can be reused.

[Effect]

By means of the present invention, when a task being executed detects a logical contradiction in software, the resources of that task, such as the control at1 table, are prohibited from being used, and the task is forcibly terminated.1. Ru. The task's service for that resource is stopped. However, for other resources (
”” Zahis is maintained possible.

〔Example〕

The details of the present invention will be explained below based on examples.

FIG. 1 is an explanatory diagram of a system according to an embodiment of the present invention.

In the figure,] 1 is a post processor, 12 is an application program, 13 is a communication access method program VTAM, 14 is a data center for dumping, 15 is a communication control processing bag WCCP,
16 is a local memory, 17 is a communication control program NC
P, 18 is a hack ground processing routine L5. 19 is a supervisor L4. 20 is a control table, 21 is a common area, 2
2 is a save area, 23 is a local processor, 24 is a register group, 25 is an operator console, and 26 is a communication line. In addition, ■ to [phase] indicate processing procedures.

Next, the operation of this embodiment will be explained according to the processing procedures from (1) to [phase].

(2) While the task L is being executed, the control table 20 is used to detect logical contradictions in the software.

(2) The L5 notifies the L4 of the software logical contradiction detection number.

(2) If L4, the contents of the common area 21, register group 24, etc. are saved to the save area 22.

■Forcibly terminate the task of L4 beam.

(2) Disable the use of the resources (control table 20) used by the L4 beam.

■L4 goes to VTAM13 of host processor 11, NC
P17 notifies that a logical contradiction has been detected and that the use of a specific resource (control table 20) has been prohibited. ■T8 to 13 outputs and displays this on the operator console.

■The operator instructs the NCP to perform a dynamic dump, and
TAM 13 instructs this to NCP 17.

(2) The contents of the local memory 16 are read out and stored in the dump data center 14.

After completion of the dump described in (■■), in order to synchronize VTAM and NCP, the VTAM 13 executes a forced deactivation to temporarily return the resource (control table 20) that caused the failure to its initial state in response to an operator's instruction.

After confirming that the resource (control table 20) has been returned to the initial state in [phase] ■, the VTAM 13 activates the resource (control table 20) to a usable state according to the operator's instructions. The NCP service using the resource (control table 20) is restarted.

In this way, NCP 17 can control table 2 in the above example.
When a logical contradiction is detected in the control table 20, its use is simply prohibited, and only the service that uses that control table 20 is stopped. For example, only a certain communication line becomes unusable. This period of partial outage lasts until VTAM reinitializes the control table 20 and commands it to resume from the IPL state, during which time the remaining NCPe
, Noh service as it is! ! can continue.

Note that in the NCP, the L4 supervisor uses flags to manage the use of each resource by permitting or prohibiting its use. For example, when the L5 task uses a resource, its flag 1 is ON: Harisodo, OFF:
Enables execution only when the flag is ON.

[Effects of the Invention] According to the present invention, even if a software failure occurs in the NCP, in most cases, only a predetermined range of services is stopped, reducing the number of cases where the NCP goes completely out of service or goes down. I can only lie down. This improves the reliability of the system and enables 24-hour operation.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a system according to an embodiment of the present invention, and FIG. 2 is a schematic diagram of an example of an information processing system targeted by the present invention. In the figure, 11 is a host processor, 12 is an application program, 13 is a communication access method program VTAM, 14 is a dump cheek set, 15 is a communication control processing unit CCP,
16 is a local memory, 17 is a communication control progera J,
N CP, 18 is a hack ground processing routine, 19
is the supervisor, 20 is the control table, 21 is the common area, 22
23 represents a save area, 23 represents a local processor, 24 represents a register group, 25 represents an operator console, and 26 represents a communication line.

Claims (1)

[Claims] In an information processing system having a host processor equipped with a communication access method program VTAM and a communication control processing device equipped with a communication control program NCP that cooperates with the communication access method program VTAM of the host processor, the communication control program NCP includes: When a certain control routine task included in its own program detects a logical contradiction in the software while it is running, it forcibly terminates the task, disables the use of the resources used by the task, and sends the above message to that effect. Notify the Access Law Program VTAM, and notify the Telecommunications Access Law Program V
The NCP down prevention method is characterized in that the TAM instructs and executes a dynamic dump to the communication control program NCP, and also initializes the previously disabled resources to make them reusable.