JPH0476622A - Load module library management processing method - Google Patents

Abstract

PURPOSE:To eliminate the need of backup processing by securing data before update to improve the substantiality of a load module library by the dual structure of an old management table and a new management table. CONSTITUTION:Dual management tables 18a and 18b are provided as the table where information for management of a load module library 17 is stored, and they are alternately used by a management table access part 14 as new and old management tables to update the generation. When contents of the library 17 are updated by a data update part 16, data other than data in tables 18a and 18b is written additionally by reserving a new area but is not overwritten. Logical stamps 19a and 19b are set to the first positions of respective areas or logical stamps 19a' and 19b' are set to the last positions of these areas in tables 18a and 18b by a logical stamp management part 15, and the validity of write to tables 18a and 18b is secured by these logical stamps.

Description

[Detailed Description of the Invention] [Summary] Regarding a load module library management processing method in a data processing system that manages a load module library, the load module library is managed with the aim of increasing robustness against failures when updating the load module library. The management table that stores information for the management table has a dual structure of old and new, and when updating the load module, data other than the management table is additionally written by securing a new area, and the validity of writing to the management table is determined by a logical stamp. The system is configured to guarantee the following.

[Industrial application field]

The present invention relates to a load module library management processing method in a data processing system that manages five load module libraries.

In recent years, making systems fault tolerant (FT) and non-stop has become an important issue.

In order to implement active maintenance of the system, it is necessary to guarantee updated data for the two-generation load module library. Therefore, there is a need for a technology that guarantees data from five updates ago even if a system failure occurs while accessing the first generation load module library.

[Prior Art] In conventional load module libraries, if the system goes down while updating a load module, the previous data, especially meta information such as space information, cannot be guaranteed.

Even the load module before the update cannot be used (sometimes it happens).

Therefore, in the conventional method, when updating the load module library, it was necessary to take a backup before updating to prepare for data destruction during the update work.

[Problem to be solved by the invention]

In the conventional technology, when implementing active maintenance of the system, it is necessary to perform bank up processing of data before updating, which takes two man-hours and has a negative impact on cost. Furthermore, when starting up the system after a failure, restoration from the bank amplifier is required, so there is a problem in that it takes time until the load module library becomes usable.

The present invention aims to solve the above problems, improves the robustness against failures when updating the load module library, and
The purpose of this invention is to provide a means that eliminates the need for bank up processing before updating and restoration processing in the event of a failure.

[Means to solve the problem]

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

In FIG. 1, 10 is a data processing bag Lll consisting of a CPU, memory, etc., is a linkage editor that creates a load module that is an executable program;
2 is a loader that loads a specified load module into the main memory; 13 is a load module library management unit that manages a load module library; 14 is a management table access unit that accesses a management table; 15
1 is a logical stamp management unit that manages logical stamps in the management table; 16 is a data update unit that updates load modules; 17 is a load module library that stores a load module group; IBa;

J8b represents a management table that stores meta information for managing the load module library, 19a19a', 19b, and 19b' represent logical stamps, and DI-D3 represents data.

In the present invention, the management table 18 is a table that stores information for managing the load module library 17.
a, 181) and are used alternately by the management table access unit 14 as new and old, respectively.
Upgrade your generation.

Load module library 1 is updated by data update unit 16.
When updating the contents of 7, management tables 18a and 18b
For data other than 5, secure a new area and write additionally.
Avoid so-called overwriting.

In the management tables 18a and 18b, the logical stamp management unit 15 adds logical stamps 19a and 19 at the beginning of each area.
b, and logical stamps 19a', 1 at the final position of each area.
9b' is set, and the validity of writing to the management file 18a, 18b is guaranteed by these logical stamps.

[Effect]

One of the management tables 18a and 18b for managing meta information of the load module library 17 is "new" and the other is "old".Due to the dependence of the loader 12, when extracting the load module, .

Use the “new” management table.

The linkage editor 11 updates the load module library 17 via the load module library management unit 13. For example, if the management table 18a is
If the management table 18b is "old", the management table to be updated is the management table 18b side.

When changing the contents of the data D2, instead of overwriting the changed contents in the storage area of the data D2, an area is reserved for 5 separate areas and the changed contents are additionally written as data D2'.

Then, point to data D2' from the management table 18b.

When the data update is completed, j) FL values are set as the logical stamps 19b and 19b' in the management table 18b, and an input/output command is issued to update the management table 18b.

If the above processing is completed normally, management table 1
The management table 8b is used as the new one, and the management table 18a is switched to the old one.

When updating the load module library 17.

When a failure such as a system down occurs, the load module library 17 becomes incomplete.

However, in case 2 of the present invention, for example, even if there is a failure when updating the management table 18b, the other management table 18b
The contents of a are guaranteed as they are, and the binary data can be used as is for the data D2 that is subject to 5 update.

〔Example〕

FIG. 2 is a diagram illustrating duplication of management tables according to an embodiment of the present invention, FIG. 3 is a data structure of a load module library according to an embodiment of the present invention, and FIG. 4 is a diagram illustrating management according to an embodiment of the present invention. Explanation of Table Validity Confirmation FIG. 2 FIG. 5 shows a processing flow at the time of updating according to an embodiment of the present invention.

In the present invention, for example, as shown in FIG. 2, one side is the old management table 18a and the other side is the new management table 18b.
The management table has a dual structure.

In normal times, the management table used for loading the load module is the new management table IBb, and when updating is required, the new and old management table 18a is used.
Write on the side. Note that the management tables 18a and 18b are
It has information for managing meta information 20 such as space management information of the data body configuring the load module.

In this embodiment, the data structure of the load module library is as shown in FIG.
a is the 0th block at the beginning, and management table 18b is the 1st block.
It is designed to be placed on each block.

Management tables 18a, 18b point to blocks called control segments 30. The control segment 30 stores meta information 20 shown in FIG. Each control segment 30 points to a corresponding lock on the load module main body 3I.

As described above, the management tables 18a and 18b are used alternately, and when the control segment 30 or the load module body 31 is updated, additional writing is always performed in the free area.

The validity of the management table is guaranteed by a logical stamp. The logical stamp is a sequence number that is incremented by 1, for example, every time an update is made.

FIG. 4(a) shows an example of logical stamps 19 and 19' for the current generation management table 18. The same value is set for the logical stamp values of ■ and ■.

Figure 4 (b) shows an example of logical stamps 19 and 19' for the new generation management table I8, where ■ and ■ are larger than the logical stamp values of ■ and ■ shown in Figure 4 (a). Therefore, the management table 18 shown in FIG. 4 (b) is better.
It can be seen that this is newer than what is shown in (a).

If a system failure occurs while the management table 18 is being updated by an input/output command, the contents of the management table 18 being updated may become undefined. Figure 4 (c)
indicates the status.

In this case, the first logical stamp 19 and the final logical stamp 19' are compared. If these values match,
The contents of the management table 18 can be considered correct. If the logical stamps 19 and 19' before and after 5 do not match, the contents of the management table 18 are incorrect, so
Discard its contents and use the other management table.

In this example, a large sequence number is used as the logical stamp value, but time information at the time of update may also be used.

The update process for the load module library 17 is performed, for example, as shown in FIG. The following will explain the processes (a) to (g) shown in FIG. 5(a).

(a) Read the management table from the load module library 17.

[Yes]) Check the validity of the logical stamp explained in FIG. The one with the same logical stamp values before and after and the latest value is recognized as the new management table, and the other is recognized as the old management table. In this example, it is assumed that the management table ■ shown in FIG. 5(b) is the new management table, and the management table ■ is the old management table.

(C) Add 1 to the value of the logical stamp in the management table ■.

(d) Write a logical stamp at the beginning of the old management table ■. Store this value as *1.

(e) Add the load module information to the new %l area and reflect the management information of the new area in the management table ■.

ffl Determine whether all necessary information has been written, and if it still remains, repeat process (e).

(Ugly) Once you have finished writing the necessary information, please fill out the management file.
Finally, a logical stamp with the same value as *1 stored in process (d) is written out, and the process ends.

As a result, the load module library 17 shown in FIG. 5(b) is updated as shown in FIG. 5(c), and the old management table, management table ■, becomes the latest management table.

[Effects of the Invention] As described above, according to the present invention, even if a load module is crashed during update, the data before update can be guaranteed. The robustness of the row 1' module library is increased, and the conventional backup process when updating a load module is no longer necessary.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention. FIG. 2 is a diagram illustrating duplication of management tables according to an embodiment of the present invention. FIG. 3 is a data structure of a load module library according to an embodiment of the present invention. FIG. 4 is an explanatory diagram of management table validity confirmation according to an embodiment of the present invention. FIG. 5 shows a processing flow at the time of updating according to an embodiment of the present invention. In the figure, 10 is a data processing word fi, +1 is a linkage editor, ]2 is a loader, 13 is a load module library management section, ]4 is a management table access section, 15 is a logical stamp management section, 16 is a data update section, and 17 is a Load module library. 18a and 18b represent management tables, 19a and 19b represent logical stamps, and D1 to D3 represent data.

Claims (1)

[Claims] A load module which is an executable program,
In a data processing system managed as a load module library (17), the management tables (18a, 18b) that store information for managing the load module library have a dual structure of old and new management tables. Data other than the above will be additionally written by securing a new area, and the validity of writing to the management table is determined by the logical stamp (19
A load module library management processing method characterized by ensuring the following: a, 19b).