Techniques to provide a flexible witness in a distributed system

A method comprising:

• deploying a cloud witness service and one or more local witness services to selectively serve one or more cluster sites each having at least two storage/compute nodes, the one or more local witness services running on one or more external devices local to an associated cluster site of the one or more cluster sites, the cloud witness service running on a central cloud management platform that is remote from the one or more cluster sites;
• managing the cloud witness service and the one or more local witness services with the central cloud management platform;
• and
• selectively performing arbitration services with either the cloud witness service or one of the one or more local witness services if a partition in one of the one or more cluster sites fails or communication between partitions in one of the one or more cluster sites fails,
• wherein the one or more local witness services and the cloud witness service are instantiations of a witness server and are selectively reachable via a uniform service interface.

A system comprising:

• one or more cluster sites each having at least two storage/compute nodes;
• at least one local external device associated with at least one of the one or more cluster sites, the at least one local external device configured to run a local witness service;
• and
• a central cloud management platform in communication with the one or more cluster sites, the central cloud management platform configured to run a cloud witness service, and to manage the local witness service and the cloud witness service,
• wherein the local witness service and the cloud witness service are each configured to selectively perform identical arbitration services if a storage/compute node in one of the one or more cluster sites fails or communication between storage/compute nodes in a cluster fails, and wherein the local witness service and the cloud witness service are instantiations of a witness server and are selectively reachable via a uniform service interface, and
• wherein the central cloud management platform is configured to determine which of the cloud witness service and local witness service is a presiding witness service, at any given time, for a corresponding one of the one or more cluster sites.