Abstract: Various systems and methods for managing node connectivity in distributed storage systems are disclosed. For example, one method involves detecting a communication fault between two nodes. A first node is configured to communicate input/output (I/O) requests to the second node as in-flight I/O requests. The second node is configured to communicate locally generated I/O requests and the received I/O requests to storage devices. Once the communication fault is detected, a fencing operation is performed. The fencing operation can include processing some of the received I/O requests by the second node, and rejecting any additional in-flight I/O requests received from the first node.

Abstract: Various systems and methods for performing Input/Output (I/O) quiesce and drain operations in multi-node distributed storage systems are disclosed. For example, one method involves receiving a message. The message indicates a request for a operation to be performed by a node, where the node can receive I/O requests from an application, as well as remote I/O requests from another node. The node can issue the I/O requests and the remote I/O requests to the one or more storage devices. In response to receipt of the message, the method performs a first portion of a operation on the node. The first portion of the operation includes the node not processing any additional locally generated I/O requests and processing additional remote I/O requests.

Abstract: Various systems and methods for determining connectivity of various elements of distributed storage systems. For example, one method involves generating first connectivity information for a node, where the node can to access data that is organized using logical objects. The logical objects include first logical objects and second logical objects. Each of the second logical objects includes one or more of the first logical objects. The first connectivity information for the node indicates accessibility of the node to the first logical objects. The method also includes generating second node connectivity information for the node, where the second connectivity information for the node indicates accessibility of the node to the second logical objects. The generating the second node connectivity information is based on the first connectivity information.

Abstract: Various systems and methods for managing node connectivity in distributed storage systems are disclosed. For example, one method involves detecting a communication fault between two nodes. A first node is configured to communicate input/output (I/O) requests to the second node as in-flight I/O requests. The second node is configured to communicate locally generated I/O requests and the received I/O requests to storage devices. Once the communication fault is detected, a fencing operation is performed. The fencing operation can include processing some of the received I/O requests by the second node, and rejecting any additional in-flight I/O requests received from the first node.

Abstract: Various systems and methods for interval-controlled replication are described. For example, one method involves a node receiving a first interval indication indicating start of a first interval. After receiving the first interval indication, an application on the node initiates a first write, which includes the node initiating a first local write and a first remote write. The first local write accesses a local storage. The first remote write accesses a remote storage and replicates the first local write. The node waits for acknowledgements indicating that the local and remote writes have finished, as well as for a second interval indication, before the first write from the application is treated being complete.

Abstract: Various systems and methods for interval-controlled replication are described. For example, one method involves a node receiving a first interval indication indicating start of a first interval. After receiving the first interval indication, an application on the node initiates a first write, which includes the node initiating a first local write and a first remote write. The first local write accesses a local storage. The first remote write accesses a remote storage and replicates the first local write. The node waits for acknowledgements indicating that the local and remote writes have finished, as well as for a second interval indication, before the first write from the application is treated being complete.