Abstract: A method and system for increasing server cluster availability by requiring at a minimum only one node and a quorum replica set of replica members to form and operate a cluster. Replica members maintain cluster operational data. A cluster operates when one node possesses a majority of replica members, which ensures that any new or surviving cluster includes consistent cluster operational data via at least one replica member from the immediately prior cluster. Arbitration provides exclusive ownership by one node of the replica members, including at cluster formation, and when the owning node fails. Arbitration uses a fast mutual exclusion algorithm and a reservation mechanism to challenge for and defend the exclusive reservation of each member. A quorum replica set algorithm brings members online and offline with data consistency, including updating unreconciled replica members, and ensures consistent read and update operations.

Abstract: A method and system for increasing server cluster availability by requiring at a minimum only one node and a quorum replica set of replica members to form and operate a cluster. Replica members maintain cluster operational data. A cluster operates when one node possesses a majority of replica members, which ensures that any new or surviving cluster includes consistent cluster operational data via at least one replica member from the immediately prior cluster. Arbitration provides exclusive ownership by one node of the replica members, including at cluster formation, and when the owning node fails. Arbitration uses a fast mutual exclusion algorithm and a reservation mechanism to challenge for and defend the exclusive reservation of each member. A quorum replica set algorithm brings members online and offline with data consistency, including updating unreconciled replica members, and ensures consistent read and update operations.

Abstract: A method and system for increasing server cluster availability by requiring at a minimum only one node and a quorum replica set of replica members to form and operate a cluster. Replica members maintain cluster operational data. A cluster operates when one node possesses a majority of replica members, which ensures that any new or surviving cluster includes consistent cluster operational data via at least one replica member from the immediately prior cluster. Arbitration provides exclusive ownership by one node of the replica members, including at cluster formation, and when the owning node fails. Arbitration uses a fast mutual exclusion algorithm and a reservation mechanism to challenge for and defend the exclusive reservation of each member. A quorum replica set algorithm brings members online and offline with data consistency, including updating unreconciled replica members, and ensures consistent read and update operations.

Abstract: A method and system for increasing server cluster availability by requiring at a minimum only one node and a quorum replica set of replica members to form and operate a cluster. Replica members maintain cluster operational data. A cluster operates when one node possesses a majority of replica members, which ensures that any new or surviving cluster includes consistent cluster operational data via at least one replica member from the immediately prior cluster. Arbitration provides exclusive ownership by one node of the replica members, including at cluster formation, and when the owning node fails. Arbitration uses a fast mutual exclusion algorithm and a reservation mechanism to challenge for and defend the exclusive reservation of each member. A quorum replica set algorithm brings members online and offline with data consistency, including updating unreconciled replica members, and ensures consistent read and update operations.

Abstract: A dependency filter object for use in a server cluster is described. In an implementation, a method includes bringing online one or more resource objects included in a dependency tree. Each of the resource objects corresponds to a resource available in a server cluster. The dependency tree includes a dependency filter object that specifies a dependency of a first one of the resource objects on a second one of the resource objects. The bringing online of the first resource object is managed according to the specified dependency on the second resource object.

Abstract: A method and system for increasing server cluster availability by requiring at a minimum only one node and a quorum replica set of replica members to form and operate a cluster. Replica members maintain cluster operational data. A cluster operates when one node possesses a majority of replica members, which ensures that any new or surviving cluster includes consistent cluster operational data via at least one replica member from the immediately prior cluster. Arbitration provides exclusive ownership by one node of the replica members, including at cluster formation, and when the owning node fails. Arbitration uses a fast mutual exclusion algorithm and a reservation mechanism to challenge for and defend the exclusive reservation of each member. A quorum replica set algorithm brings members online and offline with data consistency, including updating unreconciled replica members, and ensures consistent read and update operations.

Abstract: A virtual computing environment comprising virtual machines may be created to clone a computing environment for testing purposes. To provide an accurate testing environment, the network configuration of the cloned computing environment may be preserved in the virtual computing environment. However, deploying the virtual computing environment on a physical network that comprises the cloned computing environment may create addressing conflicts. Accordingly, a technique for preserving network configuration data without creating addressing conflicts is provided herein. A virtual computing environment comprising an internal virtual network and external virtual network is fenced off to isolate the virtual computing environment from a physical external network. The virtual computing systems are connected to the internal virtual network for communication, using the preserved network configuration, between virtual computing environments.

Abstract: In a first exemplary media implementation, one or more processor-accessible media include processor-executable instructions that, when executed, direct a system to perform actions that include: accumulating host status information at multiple hosts; and sending the accumulated host status information from the multiple hosts. In a second exemplary media implementation, one or more processor-accessible media include processor-executable instructions that, when executed, direct a system to perform actions that include: receiving host status information from multiple hosts; and making load balancing decisions responsive to the received host status information.

Abstract: A failover scope comprises a node collection in a computer cluster. A resource group (e.g., application program) is associated with one or more failover scopes. If a node fails, its hosted resource groups only failover to nodes identified in each resource group's associated failover scope(s), beginning with a first associated failover scope, in order, thereby defining an island of nodes within which a resource group can failover. If unable to failover to a node of a resource group's first failover scope, failover is attempted to a node represented in any next associated failover scope, which may require manual intervention. Failover scopes may represent geographic sites, whereby each resource group attempts to failover to nodes within its site before failing over to another site. Failover scopes may be managed by the cluster runtime automatically, e.g., an added node is detectable as belonging to a site represented by a failover scope.

Abstract: In a server cluster, a system and method is provided for mitigating redundant resource failure notifications and other problems resulting from late handling of messages. Traditional resource management can result in the generation of redundant resource failure notifications that trigger unnecessary recovery actions, or cause other cluster problems such as performing an action that has previously been handled as part of failure recovery. The present invention tracks resource failures and eliminates recovery actions for redundant resource failure notifications. An incarnation number is passed to a resource each time it is called, and is incremented whenever a resource failure notification is delivered. Failure notifications having an incarnation number lower than the current incarnation number are discarded.

Abstract: A method and system for increasing server cluster availability by requiring at a minimum only one node and a quorum replica set of replica members to form and operate a cluster. Replica members maintain cluster operational data. A cluster operates when one node possesses a majority of replica members, which ensures that any new or surviving cluster includes consistent cluster operational data via at least one replica member from the immediately prior cluster. Arbitration provides exclusive ownership by one node of the replica members, including at cluster formation, and when the owning node fails. Arbitration uses a fast mutual exclusion algorithm and a reservation mechanism to challenge for and defend the exclusive reservation of each member. A quorum replica set algorithm brings members online and offline with data consistency, including updating unreconciled replica members, and ensures consistent read and update operations.

Abstract: In a server cluster, a system and method is provided for mitigating redundant resource failure notifications and other problems resulting from late handling of messages. Traditional resource management can result in the generation of redundant resource failure notifications that trigger unnecessary recovery actions, or cause other cluster problems such as performing an action that has previously been handled as part of failure recovery. The present invention tracks resource failures and eliminates recovery actions for redundant resource failure notifications. An incarnation number is passed to a resource each time it is called, and is incremented whenever a resource failure notification is delivered. Failure notifications having an incarnation number lower than the current incarnation number are discarded.

Abstract: A failover scope comprises a node collection in a computer cluster. A resource group (e.g., application program) is associated with one or more failover scopes. If a node fails, its hosted resource groups only failover to nodes identified in each resource group's associated failover scope(s), beginning with a first associated failover scope, in order, thereby defining an island of nodes within which a resource group can failover. If unable to failover to a node of a resource group's first failover scope, failover is attempted to a node represented in any next associated failover scope, which may require manual intervention. Failover scopes may represent geographic sites, whereby each resource group attempts to failover to nodes within its site before failing over to another site. Failover scopes may be managed by the cluster runtime automatically, e.g., an added node is detectable as belonging to a site represented by a failover scope.

Abstract: A method and system for increasing server cluster availability by requiring at a minimum only one node and a quorum replica set of replica members to form and operate a cluster. Replica members, independent from the nodes, maintain cluster operational data. A cluster operates when one node possesses a majority of replica members, which ensures that any new or surviving cluster includes consistent cluster operational data via at least one replica member from the immediately prior cluster. Arbitration provides exclusive ownership by one node of the replica members, including at cluster formation, and when the owning node fails. Arbitration uses a fast mutual exclusion algorithm and a reservation mechanism to challenge for and defend the exclusive reservation of each member. A quorum replica set algorithm brings members online and offline with data consistency, including updating unreconciled replica members, and ensures consistent read and update operations.

Abstract: A method and system for increasing server cluster availability by requiring at a minimum only one node and a quorum replica set of replica members to form and operate a cluster. Replica members, independent from the nodes, maintain cluster operational data. A cluster operates when one node possesses a majority of replica members, which ensures that any new or surviving cluster includes consistent cluster operational data via at least one replica member from the immediately prior cluster. Arbitration provides exclusive ownership by one node of the replica members, including at cluster formation, and when the owning node fails. Arbitration uses a fast mutual exclusion algorithm and a reservation mechanism to challenge for and defend the exclusive reservation of each member. A quorum replica set algorithm brings members online and offline with data consistency, including updating unreconciled replica members, and ensures consistent read and update operations.

Abstract: In a first exemplary media implementation, one or more processor-accessible media include processor-executable instructions that, when executed, direct a system to perform actions that include: accumulating host status information at multiple hosts; and sending the accumulated host status information from the multiple hosts. In a second exemplary media implementation, one or more processor-accessible media include processor-executable instructions that, when executed, direct a system to perform actions that include: receiving host status information from multiple hosts; and making load balancing decisions responsive to the received host status information.

Abstract: A method and system wherein following a partitioning of a server cluster, operational subgroups arbitrate for possession of a quorum resource that determines cluster representation, wherein the arbitration is biased by a relative weight of the subgroup. The weight may be relative to the original cluster weight, or submitted as a bid that is relative to other possible subgroup weights. The biasing gives subgroups that are better capable of representing the cluster an arbitration advantage over lesser subgroups. The biasing weight of each subgroup may be determined by node count and/or by a calculation of the subgroup's resources. The arbitration may be delayed based on the relative weight, or alternatively, the arbitration may comprise a bidding process in which a subgroup's bid is based on the subgroup's relative weight.

Abstract: A custom palette comprises colors on a plurality of luminance levels consisting of colors of uniform luminance. The spacing in luminance between levels varies in relation to the luminance, the spacing between levels being closer at low luminance and increasing at greater luminance. The palette preferably includes a gray color from each luminance level, highly saturated colors at the vertices of every alternate level, and a selection of lower saturation colors encircling the gray color on each level. The selection of lower saturation colors preferably includes a higher concentration of flesh and sky colors.

Abstract: A method and system for increasing server cluster availability by requiring at a minimum only one node and a quorum replica set of replica members to form and operate a cluster. Replica members, independent from the nodes, maintain cluster operational data. A cluster operates when one node possesses a majority of replica members, which ensures that any new or surviving cluster includes consistent cluster operational data via at least one replica member from the immediately prior cluster. Arbitration provides exclusive ownership by one node of the replica members, including at cluster formation, and when the owning node fails. Arbitration uses a fast mutual exclusion algorithm and a reservation mechanism to challenge for and defend the exclusive reservation of each member. A quorum replica set algorithm brings members online and offline with data consistency, including updating unreconciled replica members, and ensures consistent read and update operations.

Abstract: A method and system for forming a new cluster of servers having state data that is consistent with the state data of a cluster that previously existed. The previous cluster preserves its state data by recording transactions to a log file in conjunction with a sequence number maintained by each node. The node that recorded the transaction then increments its copy of the sequence number and attempts to replicate the transaction to other nodes of the cluster. If the transaction is replicated, each other node commits the transaction and increments its sequence number. If the node fails before it can replicate the transaction, then no other nodes will increment their sequence numbers, whereby the next logged transaction has the same sequence number as the previously logged, but orphaned replicated transaction. When a new node forms a cluster, it unrolls the log file so as to become consistent with the state of the previous cluster.