Method and system for using temporary exclusive blocks for parallel accesses to operating means

摘要

In at least one example embodiment, the invention relates to a computer-implemented method, a computer-implemented system and a computer program product for controlling the access to splittable resources in a distributed client server system operating in parallel. The resource control system is designed for a plurality of clients connected to the system and is used to maintain consistency of the data. When a client makes a first attempt to access a resource of the server, an exclusive lock for the requested resource is allocated to the accessing client, that blocks the access to the resource for other clients, said exclusive lock only being allocated for a pre-determinable period of time and then automatically discontinued.

主权项

1. A computer-implemented method for controlling an access to sharable resources in a distributed client-server system in parallel operation, wherein a control function is performed centrally for a plurality of clients connected to the distributed client-server system, the control function comprising:
registering an access request from an accessing one of the plurality of clients that is requesting access to one of the sharable resources; determining a time interval for the accessed one of the sharable resource to be blocked from access by other of the plurality of clients based on a type of the one of the sharable resources and a type of the access request, where the type of the access request is one of requests to READ, WRITE, EXE, LIST and QUERY the sharable resource; allocating an exclusive lock, for the accessed one of the sharable resources, to the accessing client, the exclusive lock blocking access by other of the plurality of clients to the accessed one of the sharable resources and the exclusive lock being allocated for the time interval and then automatically expiring after the time interval elapses; providing the accessing client with meta information indicating the time interval for which the accessing client is assigned the exclusive lock; allowing one of the plurality of clients to re-obtain an exclusive lock on one of the sharable resources if the requested sharable resource had formerly been blocked for the one of the plurality of clients by way of an exclusive lock and if the one of the plurality of clients wishes to access the requested sharable resource by way of a REGAIN request; and sending an UPDATE to the client in respect of the sharable resource in response to the REGAIN request for the same sharable resource, the UPDATE including changes made in a time period between expiration of a previous exclusive lock and the allocation of a subsequent exclusive lock for the one of the plurality of clients in respect of the requested sharable resource.