JPS5816492B2 - Shared exclusive control method for data sets - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides that upon access by a host processing system or multiple host processing systems to a data set within a data volume, the entire occupancy of said data volume by a job of either host processing system is 6 For example, as shown in Figure 1, data sets stored in a data volume can be shared between multiple host processing systems and In the case where the data set A is shared by the host processing system ■, if the data set A is accessed by the job, the host processing system ■ is the data server.
- Issue a RESERVE command to A.

At this time, if this RESERVE command is issued to dataset A via path I-I, controller ■, and path ■, the controller performs path reservation using the access paths of path I-I and path ■. .

Therefore, while this path reservation is being performed, even if the host processing system ■ needs to access data set B, the data volume is
- Since the path is reserved for host processing system ■ by I and cannot be accessed, the state is the same as if the entire data volume set was occupied by host processing system I via controller ■, and host processing system I's job processing had to be significantly delayed.

Moreover, even if the host processing system ■ accesses data set A through the path ■-L second controller and the route via path ■, the path I-I reserved for path reservation, the first There is a problem in that only the route from the controller and path mR can be used, and the double route provided to improve system reliability may become useless.

In addition, when multiple jobs are executed on the host processing system I or I and a data set is shared or used exclusively, (A) this is done when the data set is opened, and (B) the data set is accessed. This control is sometimes performed by a system management program.

In this case, shared or exclusive control is performed by comparing the attributes of the data set and the processing format.

The attributes of this dataset include (a) those that can be shared by multiple read jobs or one write job;
(b) Can be shared by multiple read jobs and one write job; (e) Can be shared by multiple jobs regardless of processing type (reading, writing); and (a') There is only reading (b'l writing (creation of data set)), updating (reading, writing), etc.

If shared exclusive control is performed when the above human data is opened, the burden on the job will be small, but there is a problem that the exclusive time will be longer, so this control should be performed when accessing the data set (B) above. There are cases where it is done.

In the case of (B), a unique password corresponding to the data set is determined between jobs that share the data set, and sharing is allowed when the data set is opened prior to access.

Then, when it is desired to temporarily occupy the data set for a job, an ENQ macro command is issued.

At this time, the operand of the ENQ macro instruction is the above password, and the system management program checks whether another job has already issued the ENQ macro instruction using that password, and if it has already been issued, , first EN
Since the job that issued the Q macro instruction issues the DEQ macro instruction and finishes occupying the data set, the execution of the ENQ macro instruction issued later is made to wait.

Therefore, the above case can be summarized as follows.

(b) When two jobs share and exclusively use one data set, the control expected by the jobs is the same regardless of whether the jobs are running within the same host processing system or between different host processing systems. However, the RESERVE instruction must be issued between different host processing systems, and the ENQ macro instruction must be issued within the same host processing system. The macro instructions to be issued are different.

(b) When issuing the above RESERVE command, the path is reserved, and this function cannot be utilized even if an alternate path exists.

Further, other data sets in the reserved data volume are also path reserved at the same time, so they cannot be accessed from other host processing systems.

The present invention solves the above-mentioned problems by minimizing the time required for a job to occupy the entire data volume in a single system or among multiple systems, so that as soon as the required data set is processed, other jobs can The purpose of this paper is to provide a shared exclusive control method for data sets that passes empty data volumes to users.

To this end, the sharing exclusive control scheme of data sets according to the present invention provides for controlling access to a plurality of data sets in one or more data volumes by one or more host processing systems via one or more controllers. In this method, an adapter device is provided between the controller and the data volume, the adapter device has a reserve register in which parameters for using the data volume are registered, and commands corresponding to the parameters are sent from the system. The feature is that a predetermined data set within the survey data volume is accessed to check whether the two match or do not match.

Next, one embodiment of the present invention will be described based on FIG.

In the figure, 1 is a first controller, 2 is a second controller, 3 and 4 are channel devices provided in the host processing system (I), and 5 and 6 are channel devices provided in the host processing system (I).
).

and the host processing system ■ is channel device 3 or 4.
Accordingly, the first controller 1 or the second controller 2
and the host processing system (1) is connected to the first controller 1 or the second controller by means of a channel device 5 or 6.
It is connected to controller 2.

7 is an adapter, and this adapter includes a reserve register 8 for effectively accessing the data set in the data volume 9, as described later.
will be provided.

In this reserve register 8, as shown in FIG. 3, the volume number, system ID, job ID, extent (header track number and tail track number), exclusive level, etc. are entered.

The volume number here refers to the number assigned to the many devices that make up the data volume.
The system ID is a system identifier for identifying the host processing system (I), (1), etc., and the job ID is a job identifier for identifying multiple jobs.

An extent is an address range occupied by a data set within a data volume, with a header track number indicating the first position of the address range, and a chill track number indicating the last position.

The exclusive level is the attribute of the data set described above (aXbXc).

In the present invention, when a host processing system performs a data open to access a previous data set of a data volume based on a job, or
When the NQ macro instruction is issued, a RESERVE instruction is issued with the device address that is the volume number of the specified volume, and the following parameter information (1) to (5) is sent to the controller from the host processing system in response to the RESERVE instruction. Transferred to -o-ra.

(1) System ID (2) Job ID (3) Extent (4) Exclusion level (5) Access mode Here, the access mode (5) indicates the access mode such as reading or writing.

Then, the system management program sets the above parameter information and transfers it to the controller.

Of these, the access mode is only "transferred to the controller", but other parameter information is entered in the reserve register 8 provided in the adapter 7 along with the volume number of the designated volume.

Now, when the host processing system (I) shown in FIG. 2 accesses a specific data set in the data volume 9 for a job, the host processing system (I) first goes through the channel device 3 and the first controller 1. A RESERVE command for the data volume 9 is issued.

In response to this command, parameter information including the above (1) to (5) is issued, and based on this, the first controller 1 makes the adapter 7 exclusive, and then registers the reserve register 8.
It also reads the witness information regarding the data volume,
It is checked whether the extent specified by the RESERVE command is included therein.

If it is not included, the parameter specified in the above parameter information,
The system ID, job ID, extent, exclusive level, etc. are entered in the reserve register 8.

This completes the reservation. If the specified extent has been entered in the reserve register 8, check whether the system ID and job ID specified in the above parameter information match those that have already been entered. Compare.

If they match, it can be seen that the job is ready for use because it has simply been reserved again from an already registered job.

However, if they do not match, the extent (
It can be seen that the data set) is already reserved.

Therefore, at this time, the first controller 1 compares the access mode specified in the parameter information with the exclusive level entered in the reserve register 8, and decides whether to accept or reject the RESERVE command. .

Therefore, while investigating the reserve register 8, the Itj table volume 9 and the adapter 7 are set to the occupied state, but after that (well, since they are not path reserves), if the (I re-extents do not match), the free path It is possible to simultaneously access the same data volume via the controller and (f) If the job ID and system ID match, access is possible regardless of the reserved path or access path. (Ilr) If the extents match but the system ID and job ID do not match, sharing or exclusive control is performed depending on the exclusion level of the job that issued the RESERVE command first and the access form of the RESERVE command issued later.

As described above, in the present invention, each parameter is stored in the adapter register for shared or exclusive control between systems and jobs, thereby reducing the burden on software for such control. .

Also, by not making access to datasets in a data volume dependent on reserved paths, you can immediately access other datasets for other jobs after processing a particular dataset. The time required to occupy the entire data volume is minimized to ensure efficient use.

Furthermore, accesses from different host processing systems or accesses from multiple jobs from the same host processing system can be controlled by the same RESERVE command.

[Brief explanation of drawings]

FIG. 1 shows a conventional data set sharing exclusive control method, FIG. 2 shows an embodiment of the data set sharing exclusive control method according to the present invention, and FIG. 3 shows the inside of an adapter in the method of FIG. An example of the format of the register registered in is shown below. In the figure, 1 is a first controller, 2 is a second controller,
3, 4, 5, and 6 are channel devices, 7 is an adapter, 8 is a reserve register, and 9 is a data volume.

Claims (1)

[Claims] 11. A control scheme in which a plurality of data sets in one or more data volumes are accessed by one or more host processing systems via one or more controllers, wherein an adapter device is provided between the controller and the data volumes. The adapter device is provided with a reserve register in which parameters for using the data volume are registered, and a command corresponding to the parameters is sent from the system to check whether they match or not. A shared exclusive control method for data sets, characterized in that data sets are accessed.