JPS6219957A - Preventing system for depression state of transaction - Google Patents

Abstract

PURPOSE:To prevent the generation of a depression phenomenon where the transactions of a specific group are kept under a queuing state for processing for a long period of time, by processing with priority the transactions of a group whose processing result value does not reach the processing security level. CONSTITUTION:The priority is set in 0-14 steps and the more the number of steps the higher the priority. The transaction processing queue 10 has a search chain for each priority. The transaction group table 12 provided to each transaction group is connected to the search chain of the queue 10 in accordance with each priority. The transactions 14 are connected to the tables 12 of each group in the order of arrival.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to transaction scheduling in an online system, and in particular, to preventing low-priority transactions from sinking in an online system that processes and executes transactions according to priority. Regarding the method of

[Background of the invention]

Conventionally, a method using limit priority and limit value is known as a method to prevent transactions from sinking in online systems (Hitachi, Ltd.: IIITAC Manual 7).
Ii VO53DCCMII Explanation 8090-6
-321), this is a method in which when the number of queued transactions in a group exceeds a limit value, the priority of that group is temporarily raised to the limit priority, and the accumulated transactions are processed preferentially. By setting appropriate limit priorities and limit values, sinking can be prevented. but,
Since the appropriate value itself changes depending on the transaction load situation, it is practically difficult to determine the appropriate value for all groups in advance, and there is a risk that stagnation will continue to occur under inappropriate setting values. there were.

[Purpose of the invention]

An object of the present invention is to provide a means for preventing a phenomenon in which transactions of a certain group, especially a low priority group, are left unprocessed for a long time in an online system where transactions of multiple groups coexist. It is.

[Summary of the invention]

In order to prevent the transactions of a specific group of online systems from sinking, set a certain processing guarantee value for the group, and ensure that the processing performance value (number of transactions that have already been processed) of the group is still below the processing guarantee value. As long as it doesn't reach.

Regardless of the priority, it is sufficient to process transactions in a group with priority over transactions in groups whose processing performance value has already reached the guaranteed processing value.The guaranteed processing value is specified for each transaction group. The processing performance value is cleared to zero when the sum of the processing performance values of each group reaches a certain value. Note that among groups whose processing performance values do not reach the guaranteed processing value, the transactions of the group with the higher priority are processed preferentially. The same applies to groups whose processing performance values have both reached the guaranteed processing value.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1, 2, and 3.

FIG. 1 shows the table structure of the transaction processing queue of the online system. It is now assumed that there are 15 levels of priority from 0 to 14, and the higher the number, the higher the priority. 10 is a transaction processing queue, which has a search chain for each priority. A transaction group table 12 that exists for each transaction group searches the transaction processing queue 10 according to its priority.
connected to a chain. Each transaction 14 is connected to the transaction group table 12 of the group to which it belongs on a first-come, first-served basis.

FIG. 2 shows the entry configuration of the transaction group table 12. 16 indicates a guaranteed processing value for this group, which is set in advance as an external parameter.

18 is the processing performance value, which is the number of transactions of this group that have been processed since the last time the transaction was cleared to zero.

20 is an entry indicating the number of transactions currently waiting for processing execution in this group. Here, the processing result values are cleared to zero all at once when the sum of the processing result values of each transaction group reaches a certain value. Also, in 22.24, the forward pointer and backward pointer of the search chain are cleared to zero. This is the entry to enter.

FIG. 3 is a flowchart for selecting a transaction to be processed next using the tables shown in FIGS. 1 and 2. First, the search is started from the group 26 with the highest priority of 14. At 30, point the transaction group table to L, and at 32, confirm that there is a transaction waiting to be processed in the group, and at 34
Compare the processing performance value of the group with the guaranteed processing value, and if the guaranteed processing value has not been reached yet, select the first transaction waiting in the first-come, first-served order in the transaction group in 36. 0 The transaction to be selected is the one in question. If it is not found in the group, proceed to the next transaction group at 30, and when the search for the transaction group of that priority is completed at 28, the search moves to a transaction group of lower priority at 40. In this way, when it is found at 38 that the search has been completed up to the transaction group with priority 0, the search ends without selecting any transaction.

(In this case, the processing performance value is the processing value, and there are no pending transactions for groups that do not return to the !II value. At this time, search is performed by removing the 34 conditions.) Transaction selection is
This is carried out when the processing of one of the transactions is completed and online system resources become available and a new transaction can be started.

According to this embodiment, in FIG. 1, transactions of a group with a priority of 14 @regardless of the arrival status, a transaction with a priority of 10
By setting processing guarantee values for groups with priority level 2 and priority level 2, it is possible to prevent transactions in these low priority groups from sinking.

[Effects of the Invention] According to the present invention, in an online system that processes transactions consisting of a plurality of groups, it is possible to prevent a sinking phenomenon in which transactions belonging to a specific group such as a low priority group are in a waiting state for a long time. It has the effect of preventing occurrence.

For example, in Figure 1, if the guaranteed processing values for four transaction groups with priorities 14, 10.10°2 are set to 50, 20, 20, 10, and the sum of the processing performance values becomes 100, each Assume that the processing performance value is cleared to zero. At this time, the ratio of the number of processed transactions for each group is approximately 50%, 20%, and 1, respectively.
0%.

Since it is 10%, it is effective to prevent transactions in low priority groups from sinking regardless of the arrival status of transactions in high priority groups.

A concise explanation on the same page. Figure 1 is a table layout diagram of the transaction processing queue of the online system, and Figure 2 is a table layout diagram of the transaction processing queue of the online system.
FIG. 3, which is an entry configuration diagram of the group table, is a flowchart when selecting a transaction to be processed.

10...Transaction processing queue, 12...Transaction group table, 14...Transaction, 16...Processing setting value, 18...Processing result value, 20...Number of transactions waiting to be processed, 22
...Forward pointer, 24...Bank word pointer, 26-40...Transaction to be processed lth

Claims (1)

[Claims] In an online system that processes transactions made up of multiple groups, a table that has, for each group, an entry that indicates a preset processing guarantee value and an entry that indicates a processing performance value that is the number of transactions that have already been processed in the group. The feature is that by providing priority processing to transactions in groups whose actual processing value does not reach the guaranteed processing value, it prevents the occurrence of a sinking phenomenon in which transactions in a specific group are left waiting for processing for a long time. A method to prevent transaction sinking.