Abstract: Provided are techniques related generally to computer communication and, more specifically, to techniques that provide legacy applications with access to a cluster infrastructure. A pseudo interface layer provides applications with internet protocol (IP) family sockets access to cluster awareness protocols in a manner that may be transparent to both the application and the cluster awareness layer of a kernel.

Abstract: Provided are techniques related generally to computer communication and, more specifically, to techniques that provide legacy applications with access to a cluster infrastructure. A pseudo interface layer provides applications with internet protocol (IP) family sockets access to cluster awareness protocols in a manner that may be transparent to both the application and the cluster awareness layer of a kernel.

Abstract: Communication between clusters of processing nodes is initiated by designating a link layer address and a target node name in a remote cluster. The link layer address is transmitted to the target node via a regular network transmission. The link layer address is stored locally in each cluster and the nodes in each cluster are signaled that a configuration change has been made, so that gateway nodes in the clusters can obtain the link layer address to use for subsequent communications with the other cluster, such as event notifications of node status changes.

Abstract: Communication between clusters of processing nodes is initiated by designating a link layer address and a target node name in a remote cluster. The link layer address is transmitted to the target node via a regular network transmission. The link layer address is stored locally in each cluster and the nodes in each cluster are signaled that a configuration change has been made, so that gateway nodes in the clusters can obtain the link layer address to use for subsequent communications with the other cluster, such as event notifications of node status changes.

Abstract: According to one aspect of the present disclosure, a method and technique for product license management for a clustered environment having a plurality of nodes is disclosed. The method includes unlocking a product on a first node of the plurality of clustered nodes; responsive to unlocking the product on the first node, indicating an unlocked status of the product on a shared storage device accessible to the plurality of clustered nodes; and transmitting a self-unlock message from the first node to remaining nodes of the cluster to enable the remaining nodes of the cluster to self-unlock the product on the respective remaining nodes based on the status indication of the shared storage device.

Abstract: According to a method of access to a shared data record subject to contemporaneous read and write access by multiple requesters, a requester reads a shared data record including a payload and a first checksum. The requester calculates a second checksum of the payload of the data record. If the first and second checksums are not equal, the requester again reads the shared data record, including a third checksum, and calculates a fourth checksum of the payload of the shared data record. If the third and fourth checksums are equal, the requester processes the shared data record as valid, and if the second and fourth checksums are equal, the requester handles the shared data record as corrupt.

Abstract: A scheme for monitoring node operational status according to communications transmits messages periodically according to a heartbeat rate among the nodes. The messages may be gossip messages containing the status of the other nodes in the pairs, are received at the nodes and indications of the communications delays of the received messages are stored, which are used to compute statistics of the stored communications delays. Parameters of the node status monitoring, which are used for determining operational status of the nodes, are adjusted according to the statistics, which may include adjusting the heartbeat rate, the maximum wait time before a message is considered missed, and/or the maximum number of missed messages, e.g., the sequence number deviation, before the node is considered non-operational (down).

Abstract: Communication ability between nodes in a cluster-based computer system is tracked to inform applications executing on the nodes of the existence and quality of the endpoint-to-endpoint communications available between the nodes. Communications between a node and other nodes are tracked, and a database records the communication ability between the node and the other nodes for each link between the nodes. The tracking and recording are repeated at the other nodes. A registration by an application executing at a particular one of the nodes to receive notifications of changes in the communication ability with another node over a particular link (or in general) will cause notification of the application when the link status changes.

Abstract: A gossiping scheme for sharing node status in a cluster of nodes provides a robust mechanism for determining node status within the cluster. Nodes transmit gossip messages to each other nodes, the gossip messages listing other nodes in the cluster that are operational. When a node does not receive a gossip message from a particular node within a predetermined time period, then the node transmits messages to the other nodes indicating that the particular node is down. However, if another node has received a packet from the particular node within the predetermined time period and receives the node down message, then the other node responds with a node alive message.

Abstract: An event notification method for distributed processing systems provides reduction of queue space and event processing bandwidth associated with duplicate events such as a particular event that is duplicated and results in multiple event notifications propagated for multiple consumers. When a duplicate event notification is received at an input to an event notification queue, rather than queuing the duplicate event notification, a sequence number of the event notification already in the queue is updated to indicate to the event consumer, exactly how many duplicate events have been received. The timestamp of the updated event notification may also be set to the timestamp of the most recently received duplicate event notification.

Abstract: An event notification method for distributed processing systems provides remote and local node event notification in systems that require local registration of an event consumer in order produce an event notifications. To provide notification of an event occurring on a remote node, either event consumers on all nodes in the cluster register locally to receive event notifications and specify that the event is a cluster event, in which case the nodes send notification of their locally-occurring events to all nodes, or remote registrations are accepted at nodes and if a local consumer for the event is not present, a listener thread registers as an event consumer. The listener thread sends the event notifications to the remote nodes registered as consumers for the event by observing communication between the event producer and the local consumer, or receiving the event notifications directly if there is no local consumer.

Abstract: A gossiping scheme for sharing node status in a cluster of nodes provides a robust mechanism for determining node status within the cluster. Nodes transmit gossip messages to each other nodes, the gossip messages listing other nodes in the cluster that are operational. When a node does not receive a gossip message from a particular node within a predetermined time period, then the node transmits messages to the other nodes indicating that the particular node is down. However, if another node has received a packet from the particular node within the predetermined time period and receives the node down message, then the other node responds with a node alive message.

Abstract: According to a method of access to a shared data record subject to contemporaneous read and write access by multiple requesters, a requester reads a shared data record including a payload and a first checksum. The requester calculates a second checksum of the payload of the data record. If the first and second checksums are not equal, the requester again reads the shared data record, including a third checksum, and calculates a fourth checksum of the payload of the shared data record. If the third and fourth checksums are equal, the requester processes the shared data record as valid, and if the second and fourth checksums are equal, the requester handles the shared data record as corrupt.

Abstract: A scheme for monitoring node operational status according to communications transmits messages periodically according to a heartbeat rate among the nodes. The messages may be gossip messages containing the status of the other nodes in the pairs, are received at the nodes and indications of the communications delays of the received messages are stored, which are used to compute statistics of the stored communications delays. Parameters of the node status monitoring, which are used for determining operational status of the nodes, are adjusted according to the statistics, which may include adjusting the heartbeat rate, the maximum wait time before a message is considered missed, and/or the maximum number of missed messages, e.g., the sequence number deviation, before the node is considered non-operational (down).

Abstract: In response to a stimulus indicating configuration of a node into a cluster of a plurality of nodes including the node, the node determines whether or not the node has a universally unique identifier (UUID), and if not, the node provides its own persistent self-assigned UUID. The node searches a cluster configuration database for a temporary identifier associated with the node. In response to the node locating the temporary identifier of the node in the cluster configuration database, the node writes its self-assigned UUID into the cluster configuration database and joins the cluster.

Abstract: Communication ability between nodes in a cluster-based computer system is tracked to inform applications executing on the nodes of the existence and quality of the endpoint-to-endpoint communications available between the nodes. Communications between a node and other nodes are tracked, and a database records the communication ability between the node and the other nodes for each link between the nodes. The tracking and recording are repeated at the other nodes. A registration by an application executing at a particular one of the nodes to receive notifications of changes in the communication ability with another node over a particular link (or in general) will cause notification of the application when the link status changes.

Abstract: A unique device name is assigned to each of a plurality of shared storage devices in a cluster configuration database defining membership of nodes in a cluster. A particular node among the nodes defined by the cluster configuration database as a member of the cluster searches the cluster configuration database for a device identifier matching a device identifier of a shared storage device hosted by the particular node. In response to finding a matching device identifier in the cluster configuration database, the particular node renames, in a local configuration maintained at the particular node, a storage device associated with the matching device identifier with the unique name assigned to that storage device in the cluster configuration database.

Abstract: A second node receives a message from a first node in a cluster environment. The message includes a unique identifier of a shared data storage device including a cluster configuration database that defines membership of nodes in a cluster. In response to receiving the message, the second node attempts to find the shared data storage device. In response to finding the shared data storage device, the second node locates and reads the cluster configuration database on the shared data storage device. The second node then assimilates a cluster configuration update indicated by the cluster configuration database.

Abstract: An event notification system for distributed processing systems provides for replacement of event identifiers associated with transient objects, such as processes within the processing system. An event management interface receives a notification from an event producer that an identifier of an event produced by the event producer is no longer valid. The event management interface blocks event notification for the event and dissociates an event registration entry associated with the event from the event identifier. A new event identifier is received from the event producer by the event management interface, which associates the registration entry with the new event identifier. Event notification for the event is then resumed.

Abstract: An event notification system for distributed processing systems provides reduction of queue space and event processing bandwidth associated with duplicate events such as a particular event that is duplicated and results in multiple event notifications propagated for multiple consumers. When a duplicate event notification is received at an input to an event notification queue, rather than queuing the duplicate event notification, a sequence number of the event notification already in the queue is updated to indicate to the event consumer, exactly how many duplicate events have been received. The timestamp of the updated event notification may also be set to the timestamp of the most recently received duplicate event notification.