Systems and methods for configuration independent unplanned failover within a cross-site storage system having bidirectional synchronous replication

A non-transitory computer-readable storage medium embodying a set of instructions, which when executed by one or more processing resources of a distributed storage system, cause the one or more processing resources to:

• establish bi-directional synchronous replication between one or more members of a first consistency group (CG1) of a primary storage site and one or more members of a second consistency group (CG2) of a secondary storage site with each storage site having read/write access while maintaining zero recovery point objective (RPO) and Zero recovery time objective (RTO);
• initiate a non-disruptive planned failover (PFO) to change a role for the secondary storage site and change a role for the primary storage site;
• initiate, with the primary storage site, a PFO out of synchronization (OOS) event;
• sending the PFO OOS event to a mediator agent of the primary storage site with no indication of a role for serving input output (IO) for the primary storage site;
• and
• sending, with the mediator agent of the primary storage site, a request for the PFO-OOS to an external mediator at a tertiary site to determine, independent of role configuration information of the primary storage site, if the primary storage site should be assigned a primary role or a secondary role for serving IO operations.

A distributed storage system comprising:

• one or more processing resource;
• and
• one or more non-transitory computer-readable medium, coupled to the one or more processing resources, having stored therein instructions that when executed by the one or more processing resource cause the one or more processing resources to:
• establishing bi-directional synchronous replication between one or more members of a first consistency group (CG1) of a primary storage site and one or more members of a second consistency group (CG2) of a secondary storage site with each storage site having read/write access while maintaining zero recovery point objective (RPO) and Zero recovery time objective (RTO);
• initiating, with the primary storage site, a planned failover (PFO) out of synchronization (OOS) event that is sent to a mediator agent with no indication of a role for serving IO for the primary storage site;
• initiate a role independent automated unplanned failover (AUFO) based on the response from the mediator agent;
• determine a role stored in a replicated database of the primary storage site;
• and
• start an AUFO-source configuration if the role in the replicated database is primary.