Abstract: Examples include group leader role queries. Examples include detection of a loss of communication, via a first communication protocol, between first and second computing devices, transmission, via a second communication protocol, of a query for information about the second computing device currently having the group leader role. Examples further include a determine not to assume the group leader role with the first computing device based on receiving a response to the query via the second communication protocol from the second computing device.

Abstract: Examples include group heartbeat information in a Domain Name System (DNS) server text record. Examples include replacement of group heartbeat information, stored in a text record of a DNS server, with current group heartbeat information of a computing device indicating that the computing device has a group leader role for a group of computing devices.

Abstract: A high-availability network device cluster role synchronization technique for devices configured with multiple network controllers is disclosed. An HA node may contain information regarding a role within a cluster for that HA node. This information should properly be maintained or erased based on a type of failover for an HA device. For example, if there is a loss of the active controller that causes only a controller failover, changes to the role of the HA node may not be necessary. Thus, an election process within a cluster may be avoided. However, if a failover of an entire HA node occurs (or restart of an HA node), role information prior to the restart may not be applicable and an election process may need to be initiated such that the cluster may continue to function. Different types of roles may exist for nodes within a cluster.

Abstract: Examples include designation of a standby node. Some examples may include designation of a new node as a standby node when new transactions logged at a master node during a loss of service between a designated standby node and the master node exceeds a transaction threshold before the duration of the loss of service exceeds a timeout threshold.

Abstract: This disclosure is directed to heartbeat messages for a high-availability redundant distributed computing environment (e.g., a quorum data storage implementation). Heartbeat messages may be sent from a node to other members of a duster as an indication of hardware state, network connectivity, and possibly application status on the sending node. If a member of a cluster (or quorum) goes silent (e.g., misses heartbeats), other members of the duster (or quorum) may consider that member (or the node that hosts that member) to be non-functional and may initiate a recovery action. Techniques are disclosed for using low-latency non-persistent storage for some heartbeat messages (referred to herein as a “non-persistent heartbeat messages”) to replace a portion of typical persistent (e.g., disk-based) heartbeat messages to reduce overall processing for periodic heartbeat messages. Further, implementations that aggregate multiple heartbeat messages from a node into a fewer number of heartbeat messages are disclosed.

Abstract: This disclosure is directed to heartbeat messages for a high-availability redundant distributed computing environment (e.g., a quorum data storage implementation). Heartbeat messages may be sent from a node to other members of a duster as an indication of hardware state, network connectivity, and possibly application status on the sending node. If a member of a cluster (or quorum) goes silent (e.g., misses heartbeats), other members of the duster (or quorum) may consider that member (or the node that hosts that member) to be non-functional and may initiate a recovery action. Techniques are disclosed for using low-latency non-persistent storage for some heartbeat messages (referred to herein as a “non-persistent heartbeat messages”) to replace a portion of typical persistent (e.g., disk-based) heartbeat messages to reduce overall processing for periodic heartbeat messages. Further, implementations that aggregate multiple heartbeat messages from a node into a fewer number of heartbeat messages are disclosed.

Abstract: Examples include group heartbeat information in a Domain Name System (DNS) server text record. Examples include replacement of group heartbeat information, stored in a text record of a DNS server, with current group heartbeat information of a computing device indicating that the computing device has a group leader role for a group of computing devices.

Abstract: A high-availability network device cluster role synchronization technique for devices configured with multiple network controllers is disclosed. An HA node may contain information regarding a role within a cluster for that HA node. This information should property be maintained or erased based on a type of failover for an HA device. For example, if there is a loss of the active controller that causes only a controller failover, changes to the role of the HA node may not be necessary. Thus, an election process within a cluster may be avoided. However, if a failover of an entire HA node occurs (or restart of an HA node), role information prior to the restart may not be applicable and an election process may need to be initiated such that the cluster may continue to function. Different types of roles may exist for nodes within a cluster.

Abstract: Examples include group leader role queries. Examples include detection of a loss of communication, via a first communication protocol, between first and second computing devices, transmission, via a second communication protocol, of a query for information about the second computing device currently having the group leader role. Examples further include a determine not to assume the group leader role with the first computing device based on receiving a response to the query via the second communication protocol from the second computing device.

Abstract: Examples include designation of a standby node. Some examples may include designation of a new node as a standby node when new transactions logged at a master node during a loss of service between a designated standby node and the master node exceeds a transaction threshold before the duration of the loss of service exceeds a timeout threshold.