Abstract: Various systems, methods, and processes to optimize partition arbitration are disclosed. In response to a cluster being partitioned into multiple network partitions, a determination is made, using a first node in a first network partition, whether the first node wins one or more coordination points. The determination of the first node is then transmitted to a second node in the first network partition. Further, another determination is made using the second node whether the second node wins one or more other coordination points other than the one or more coordination points won by the first node.

Abstract: Various methods, systems, and processes to prevent data corruption caused by a pre-existing split brain condition in a cluster are presented. In response to determining that a node is no longer part of a sub-cluster, another node in the sub-cluster is designated as a racer node. The racer node accesses a matrix, and the matrix includes information to determine whether a majority of coordination points in a cluster are accessible by nodes in the sub-cluster. Based on the accessing, a determination is made that the information indicates that the majority of coordination points are accessible by the nodes. The information is then broadcasted.

Abstract: Various systems, methods, and processes to optimize input/output (I/O) fencing operations in systems that implement coordination points are presented. A matrix is generated. The matrix includes information indicating the accessibility of one or more coordination points by a node. The method then transmits the matrix to one or more other nodes.

Abstract: Various systems, methods, and processes to optimize partition arbitration are disclosed. In response to a cluster being partitioned into multiple network partitions, a determination is made, using a first node in a first network partition, whether the first node wins one or more coordination points. The determination of the first node is then transmitted to a second node in the first network partition. Further, another determination is made using the second node whether the second node wins one or more other coordination points other than the one or more coordination points won by the first node.

Abstract: Various methods, systems, and processes to prevent data corruption caused by a pre-existing split brain condition in a cluster are presented. In response to determining that a node is no longer part of a sub-cluster, another node in the sub-cluster is designated as a racer node. The racer node accesses a matrix, and the matrix includes information to determine whether a majority of coordination points in a cluster are accessible by nodes in the sub-cluster. Based on the accessing, a determination is made that the information indicates that the majority of coordination points are accessible by the nodes. The information is then broadcasted.

Abstract: Various systems, methods, and processes to optimize input/output (I/O) fencing operations in systems that implement coordination points are presented. A matrix is generated. The matrix includes information indicating the accessibility of one or more coordination points by a node. The method then transmits the matrix to one or more other nodes.

Abstract: Various methods and systems for automatically ranking electronic communications such as emails based on both content and social factors are disclosed. One method assigns a rank to an electronic communication, where assigning the rank involves both assigning a content-based rank to the electronic communication and assigning a social rank to the electronic communication. The rank assigned to the electronic communication can include both the content-based and social rank. Alternatively, the rank can be derived from the content-based and social ranks (e.g., the rank can be an average of the content-based and social ranks).

Abstract: Various embodiments of methods and systems for dynamically switching to a new coordinator resource are disclosed. In one embodiment, a method involves receiving information identifying a new coordinator resource for use by a cluster; detecting whether each of the nodes within the cluster is committing to use the new coordinator resource; and switching from an existing coordinator resource to the new coordinator resource, in response to detecting that each of the nodes within the cluster is committing to use the new coordinator resource. This method can be performed concurrently with normal cluster operations, and thus the cluster need not be disabled to perform the switchover.

Abstract: An apparatus or method for preserving the relationships or dependencies between content of files in a file system or between content of files in separate file systems. The preservation of relationships or dependencies may require the preservation of the files and their content as well. In one embodiment, the method includes receiving a first instruction that, when implemented, performs an operation involving a first file in a file system, wherein the first file is related to the second file. In response to receiving the first instruction, a second instruction is selected that, when implemented, performs a second operation involving the first file or a second file, wherein the second instruction is implemented before or after implementing the first instruction.