Systems and methods to reduce application input/output resumption time due to a failure of a storage site or a network partition within a cross-site storage system

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 site having read/write access while maintaining zero recovery point objective (RPO) and Zero recovery time objective (RTO);
• detect a failure in a heartbeat session based on no heartbeat message being received from the secondary storage site during a predetermined time period or detect a failure in a replication session from one or more members of CG1 to one or more members of CG2;
• transition CG1 to a fast resynchronization with CG2 and start a fence state to prevent input/output (I/O) operations on the one or more members of CG1;
• start a fast resynchronization timer for a first predetermined time period;
• start a coordinated out of sync timer for a second predetermined time period that is less than the first predetermined time period;
• performing a health check task for the secondary storage site based on sending health check communications via interconnect (IC) links between the primary storage site and the secondary storage site and via a connection between an external mediator and the secondary storage site;
• and
• prematurely terminating the fast resynchronization timer to temporarily remain in the fenced state and acquiring consensus for the primary storage site from the external mediator to resume I/O operations on the one or more members of CG1 when the health check task fails to receive communications from the one or more members of CG2 via the interconnect links and via the connection between the external mediator and the secondary storage site.

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:
• 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 site having read/write access while maintaining zero recovery point objective (RPO) and Zero recovery time objective (RTO);
• detect a failure in a heartbeat session based on no heartbeat message being received from the secondary storage site during a predetermined time period or detect a failure in a replication session from one or more members of CG1 to one or more members of CG2;
• transition CG1 to a fast resynchronization with CG2 and start a fence state to prevent input/output (I/O) operations on the one or more members of CG1;
• start a fast resynchronization timer for a first predetermined time period;
• performing a health check task for the secondary storage site based on sending health check communications via interconnect (IC) links between the primary storage site and the secondary storage site and via a connection between an external mediator and the secondary storage site;
• determining a network partition when the health check task receives a response from the secondary storage site via the connection between the external mediator and the secondary storage site while failing to receive communications from the one or more members of CG2 via the interconnect links;
• and
• start a coordinated out of sync timer for a second predetermined time period that is less than the first predetermined time period to allow for recovery of the IC links.