Computer-implemented multi-resource shared lock

A server system comprising:

• a plurality of computer entities, each configured to request locks;
• multiple resources;
• and
• communication linkage between each of said computer entities and each of said multiple resources, and between each of said multiple resources, wherein:
• at least one of said computer entities is configured to request a multi-resource lock to one of said multiple resources via said communication linkage;
• said one resource is configured to determine whether a resource lock is available at said one resource and, if so, communicating with all peer said resources to determine whether a resource lock is available via said communication linkage;
• if said peer resources indicate a resource lock is available, lock all of said resources to said requesting computer entity, and said one resource communicates said lock of said resources to said requesting computer entity via said communication linkage;
• and
• if any said resource indicates contention for said multi-resource lock, said one resource communicates said contention to said requesting computer entity via said communication linkage, and said requesting computer entity backs off said multi-resource lock request and, after a random time interval, repeats said request.

A resource configuration system for use with a plurality of computer entities, each configured to request locks for resources, said system comprising:

• multiple resources;
• and
• communication interfaces configured to provide communication linkage of each of said multiple resources with respect to each of said computer entities, and to provide communication linkage of between each of said multiple resources, wherein:
• one of said resources is configured to respond to a request by one of said computer entities for a multi-resource lock to one of said multiple resources, said response comprising determining whether a resource lock is available at said one resource and, if so, communicating with all peer said resources to determine whether a resource lock is available via said communication linkage;
• if said peer resources indicate a resource lock is available, lock all of said resources to said requesting computer entity, and said one resource communicates said lock of said resources to said requesting computer entity via said communication interface;
• if any said resource indicates contention for said multi-resource lock, said one resource communicates said contention to said requesting computer entity via said communication interface, such that said requesting computer entity backs off said multi-resource lock request and, after a random time interval, repeats said request;
• and
• if said one resource determines a resource lock is available at said peer resource, and is unable to communicate with all said other resources to determine whether a resource lock is available, said one resource communicates said failure to said requesting computer entity via said communication interface, such that said requesting computer entity backs off said multi-resource request and, after a random time interval, requests a single-resource lock to a default resource of said multiple resources.

A computer program product comprising a computer usable medium storing a computer readable program when executed on at least one computer of a server system, said server system comprising a plurality of computer entities and multiple resources;

• causes the server system:
• one of said computer entities to request a multi-resource lock to one of said multiple resources;
• said one resource to determine whether a resource lock is available at said one resource and, if so, to communicate with all peer said resources to determine whether a resource lock is available;
• if said peer resources indicate a resource lock is available, to lock all of said resources to said requesting computer entity, and said one resource to communicate said lock of said resources to said requesting computer entity;
• and
• if any said resource indicates contention for said multi-resource lock, said one resource to communicate said contention to said requesting computer entity, and said requesting computer entity to back off said multi-resource lock request and, after a random time interval, to repeat said request.