Netapp, Inc.

Sohan Shetty

Akhil Kaushik

Anoop Chakkalakkal Vijayan

Dhruvil Shah

Murali Subramanian

Rakesh Bhargava

Rohit Chaudhary

Systems and methods include negotiating a primary bias state for primary and secondary storage sites when a mediator is temporarily unavailable for a multi-site distributed storage system. In one example, a computer-implemented method comprises detecting, with the primary storage site having a primary storage cluster, a temporary loss of connectivity to a mediator or a failure of the mediator. The computer-implemented method includes negotiating the primary bias state and setting the primary bias state on a secondary storage cluster of the secondary storage site when the secondary storage cluster detects a temporary loss of connectivity to the mediator, determining whether the primary storage cluster receives a confirmation of the secondary storage cluster setting the primary bias state, and setting the primary bias state on the primary storage cluster when the primary storage cluster receives the confirmation.

Methods and systems for negotiating a primary bias state in a distributed storage system

Systems and methods are described for efficiently processing events related to a relationship between a primary copy of data at a primary storage system and a mirror copy of the data at a cross-site secondary storage system of a multi-site distributed storage system. According to an example, a mediator agent that is configured on both primary and secondary storage systems provides coordination and serialization for various events generated in the relationship. The multi-site distributed storage system performs actions based on the event processing such as performing a failover operation from the primary storage system to the secondary storage system or resynchronizing the relationship to ensure application protection and availability.

Methods and systems to interface between a multi-site distributed storage system and an external mediator to efficiently process events related to continuity

Multi-site distributed storage systems and computer-implemented methods are described for providing common snapshot retention and automatic fanout reconfiguration for an asynchronous leg after a failure event that causes a failover from a primary storage site to a secondary storage site. A computer-implemented method comprises providing an asynchronous replication relationship with an asynchronous update schedule from one or more storage objects of the first storage node to one or more replicated storage objects of the third storage node, creating a snapshot copy of the one or more storage objects of the first storage node, transferring the snapshot copy to the third storage node based on an asynchronous mirror policy, and intercepting the snapshot create operation on the primary storage site and transferring the snapshot copy to the second storage node to provide a common snapshot between the second storage node and the third storage node.

Methods and multi-site systems to provide recovery point objective (RPO) protection, snapshot retention between secondary storage site and tertiary storage site, and automatically initiating realignment and reconfiguration of a protection configuration from the secondary storage site to the tertiary storage site upon primary storage site failure

A computer-implemented method comprises providing a synchronous replication relationship from one or more storage objects of a first storage node to one or more replicated storage objects of a second storage node, providing an asynchronous replication relationship with an asynchronous update schedule from the one or more storage objects of the first storage node to one or more replicated storage objects of the third storage node to provide a protection configuration, tracking, with the third storage node of the tertiary site, a state of the secondary storage site, automatically performing a failover from the primary storage site to the secondary storage site and activating a synchronous mirror copy for the one or more replicated storage objects of the second storage node, and automatically initiating realignment and reconfiguration of the protection configuration to the tertiary storage site based upon the state of the secondary storage site.

Methods and multi-site systems to provide recovery point objective (RPO) protection and automatically initiate realignment and reconfiguration of a protection configuration from the secondary storage site to the tertiary storage site upon primary storage site failure

Multi-site distributed storage systems and computer-implemented methods are described for improving a resumption time of input/output (I/O) operations during an automatic unplanned failover (AUFO). A computer-implemented method includes determining, with a second storage cluster, whether heartbeat information from one or more storage objects of a CG of a first set of CGs is received during a time period, determining an out of sync state for a data replication relationship between the CG of the first set of CGs and a mirrored CG of a second set of CGs when the heartbeat information is not received during the time period and sending a single bulk role change call with a cluster identifier from the second cluster to an external mediator to provide a role change from follower to leader in the second set of CGs.

Methods and systems to improve input/output (I/O) resumption time by batching multiple non-conflicting operations during a non-disruptive automatic unplanned failover from a primary copy of data at a primary storage system to a mirror copy of the data at a cross-site secondary storage system

Systems and methods for reducing delays between the time at which a need for a resynchronization of data replication between a volume of a local CG and its peer volume of a remote CG is detected and the time at which the resynchronization is triggered (Reseed Time Period) are provided. According to an example, information indicative of the direction of data replication between the volume and the peer volume is maintained within a cache of a node. Responsive to a disruptive operation (e.g., relocation of the volume from a first node to a second node), the Reseed Time Period is lessened by proactively adding a passive cache entry to a cache within the second node at the time the CG relationship is created when the second node represents an HA partner of the first node and prior to the volume coming online when the second node represents a non-HA partner.

Facilitating immediate performance of volume resynchronization with the use of passive cache entries

Multi-site distributed storage systems and computer-implemented methods are described for improving a resumption time for processing of input/output (I/O) operations during an automatic unplanned failover (AUFO). A first storage cluster includes a first set of consistency groups (CGs) and a second storage cluster includes a second mirrored set of CGs. A computer-implemented method includes prefetching, with a user space of the second storage cluster, configuration information from a replicated database prior to starting the AUFO workflow, sending the configuration information to a kernel space of the second storage cluster on a per CG level while queuing the AUFO workflow, and determining if any in progress workflows conflict with the AUFO workflow.

Methods and systems to improve resumption time of input/output (I/O) operations based on prefetching of configuration data and early abort of conflicting workflows during a non-disruptive automatic unplanned failover from a primary copy of data at a primary storage system to a mirror copy of the data at a cross-site secondary storage system

Systems and methods for re-aligning data replication configuration of a cross-site storage solution after a failover are provided. According to one embodiment, after a failover, the new primary distributed storage system orchestrates flipping of the data replication configuration of a peered consistency group (CG) to reestablish zero RPO and zero RTO protections for the peered CG. The primary causes the secondary distributed storage system to perform an atomic database operation on its remote configuration database to (i) delete an existing source configuration that identifies the secondary as a source of data replication; and (ii) persist a new destination configuration identifying the secondary as a destination of data replication. Then, the primary performs an atomic database operation on its local configuration database to (i) delete an existing destination configuration identifying the primary as the destination; and (ii) persist a new source configuration identifying the distributed storage system as the source.

Re-aligning data replication configuration of primary and secondary data serving entities of a cross-site storage solution after a failover event

Systems and methods for reducing delays between the time at which a need for a resynchronization of data replication between a volume of a local CG and its peer volume of a remote CG is detected and the time at which the resynchronization is triggered (Reseed Time Period) are provided. According to an example, information indicative of the direction of data replication between the volume and the peer volume is maintained within a cache of a node. Responsive to a disruptive operation (e.g., relocation of the volume from an original node to a new node), the Reseed Time Period is lessened by proactively adding a passive cache entry to a cache within the new node at the time the CG relationship is created when the new node represents an HA partner of the original node and prior to the volume coming online when the new node represents a non-HA partner.

Growing community of inventors

Bengaluru, India

Sohan Shetty