Abstract: The acquisition of a lock among nodes of a divided cluster is disclosed. A method is performable by each of at least one node of the cluster. A node waits for a delay corresponding to its identifier. The node asserts intent to acquire the lock by writing its identifier to X and Y variables where another node has failed to acquire the lock. The node waits for another node to acquire the lock where the other node has written to X, and proceeds where Y remains equal to its own identifier. The node waits for another node to acquire the lock where the other node has written to a Z variable, and writes its own identifier to Z and proceeds where the other node has failed. The node writes a value to Y indicating that it is acquiring the lock, and maintains acquisition by periodically writing to Z.

Abstract: A method for communicating node liveness in a multinode data processing system employs an operating system function that provides a degree of self-awareness in “sensing” an imminent but still pending failure as the basis for providing special flag signals over a channel which employs nonvolatile storage in a heartbeat signaling path.

Abstract: The determination of node and/or adapter liveness in a distributed network data processing system is carried out via one messaging protocol that can be assisted by a second messaging protocol which is significantly less susceptible to delay, especially memory blocking delays encountered by daemons running on other nodes. The switching of protocols is accompanied by controlled grace periods for needed responses. This messaging protocol flexibility is also adapted for use as a mechanism for controlling the deliberate activities of node addition (birth) and node deletion (death).

Abstract: A system, method and computer readable medium are provided for monitoring functionality of multiple network interfaces and providing fault recovery. The network interfaces are grouped into nodes and a monitoring address is assigned to each of the network interfaces such that the monitoring address for each of the network interfaces is on a different subnet than the monitoring addresses for all of the other network interfaces in the same node as that network interface. According to the method, each of the network interfaces is assigned one or more recovery addresses that each are different than its monitoring address. A monitoring message is periodically sent to each of the network interfaces via the monitoring addresses in order to determine the functionality of the network interfaces. If no monitoring message is received within a predetermined period, a recovery operation is performed for one of the network interfaces using one or more recovery addresses of the one network interface.

Abstract: A system to improve communication security in cluster machine processing may include interconnected computers that can jointly process data. The system may also include a shared secret key used by each of the interconnected computers to encrypt, decrypt, and/or authenticate data being sent, or received, from one of the interconnected computers to another of the interconnected computers. The system may further include a new shared secret key used by each of the interconnected computers to encrypt, decrypt, and/or authenticate data being sent, or received, from one of the interconnected computers to another of the interconnected computers. In addition, the new shared secret key may coexist with the shared secret key without adversely affecting the joint processing of data performed by the plurality of interconnected computers.

Abstract: A method for managing node-specific quorum roles in a cluster of nodes. The method comprises assigning a configuration change of node role attributes to a node in the cluster, with each attribute being represented by a bit of a binary value. The binary value corresponding to the specified node role attributes is converted to an integer value and the integer value is stored in a node record associated with the node. The node record is accessed to isolate each bit of the integer value associated with the node and the node role attributes assigned to the node are identified from each of the isolated bits of the integer value associated with the node. A determination of whether the configuration change can be safely supported by a configuration quorum of nodes required to represent the cluster's configuration accurately is made based on the identified node role attributes.

Abstract: A method is provided for establishing clusters in a distributed data processing environment having a plurality of nodes. The frequency of messages sent for the purpose of cluster formation is selected based on ranking of the nodes. Higher ranking nodes transmit such messages more frequently than lower ranking nodes. Lower ranked nodes thus are provided with an opportunity to join a cluster without first having to transmit their own messages to effectuate the joining.

Abstract: A method is provided for establishing clusters in a distributed data processing environment having a plurality of nodes. The frequency of messages sent for the purpose of cluster formation is selected based on ranking of the nodes. Higher ranking nodes transmit such messages more frequently than lower ranking nodes. Lower ranked nodes thus are provided with an opportunity to join a cluster without first having to transmit their own messages to effectuate the joining.

Abstract: A system, method and computer readable medium are provided for configuring network interfaces grouped into nodes for monitoring functionality. According to the method, a base address and subnet mask for the network interfaces are received, and a monitoring address is automatically generated for each of the network interfaces based on the base address, the subnet mask, and the nodes. The monitoring addresses is generated such that the monitoring address for each of the network interfaces is on a different subnet than the monitoring addresses for all of the other network interfaces in the same node as that network interface. Additionally, the monitoring addresses are assigned to the network interfaces for use by the monitoring process, with each of the monitoring addresses being assigned by being added as an additional network interface address of its network interface. Also provided is a method for monitoring functionality of network interfaces and providing fault recovery.

Abstract: The determination of node and/or adapter liveness in a distributed network data processing system is carried out via one messaging protocol that can be assisted by a second messaging protocol which is significantly less susceptible to delay, especially memory blocking delays encountered by daemons running on other nodes. The switching of protocols is accompanied by controlled grace periods for needed responses. This messaging protocol flexibility is also adapted for use as a mechanism for controlling the deliberate activities of node addition (birth) and node deletion (death).

Abstract: The determination of node and/or adapter liveness in a distributed network data processing system is carried out via one messaging protocol that can be assisted by a second messaging protocol which is significantly less susceptible to delay, especially memory blocking delays encountered by daemons running on other nodes. The switching of protocols is accompanied by controlled grace periods for needed responses. This messaging protocol flexibility is also adapted for use as a mechanism for controlling the deliberate activities of node addition (birth) and node deletion (death).

Abstract: A method for communicating node liveness in a multinode data processing system employs an operating system function that provides a degree of self-awareness in “sensing” an imminent but still pending failure as the basis for providing special flag signals over a channel which employs nonvolatile storage in a heartbeat signaling path.

Abstract: The determination of node and/or adapter liveness in a distributed network data processing system is carried out via one messaging protocol that can be assisted by a second messaging protocol which is significantly less susceptible to delay, especially memory blocking delays encountered by daemons running on other nodes. The switching of protocols is accompanied by controlled grace periods for needed responses. This messaging protocol flexibility is also adapted for use as a mechanism for controlling the deliberate activities of node addition (birth) and node deletion (death).

Abstract: The determination of node and/or adapter liveness in a distributed network data processing system is carried out via one messaging protocol that can be assisted by a second messaging protocol which is significantly less susceptible to delay, especially memory blocking delays encountered by daemons running on other nodes. The switching of protocols is accompanied by controlled grace periods for needed responses. This messaging protocol flexibility is also adapted for use as a mechanism for controlling the deliberate activities of node addition (birth) and node deletion (death).

Abstract: A system, method and computer readable medium are provided for configuring network interfaces grouped into nodes for monitoring functionality. According to the method, a base address and subnet mask for the network interfaces are received, and a monitoring address is automatically generated for each of the network interfaces based on the base address, the subnet mask, and the nodes. The monitoring addresses is generated such that the monitoring address for each of the network interfaces is on a different subnet than the monitoring addresses for all of the other network interfaces in the same node as that network interface. Additionally, the monitoring addresses are assigned to the network interfaces for use by the monitoring process, with each of the monitoring addresses being assigned by being added as an additional network interface address of its network interface. Also provided is a method for monitoring functionality of network interfaces and providing fault recovery.

Abstract: A method is provided for establishing clusters in a distributed data processing environment having a plurality of nodes. The frequency of messages sent for the purpose of cluster formation is selected based on ranking of the nodes. Higher ranking nodes transmit such messages more frequently than lower ranking nodes. Lower ranked nodes thus are provided with an opportunity to join a cluster without first having to transmit their own messages to effectuate the joining.

Abstract: In distributed multinode data processing systems, mechanisms are employed to insure that the nodes are properly informed about the liveness of the other nodes in node groups in the network. In particular, the present invention employs group membership indicia as part of a mechanism for detecting that a node and/or its adapter have failed and have been recently restarted. Having detected this situation, group membership inconsistencies which it can engender are avoided.

Abstract: The determination of node and/or adapter liveness in a distributed network data processing system is carried out via one messaging protocol that can be assisted by a second messaging protocol which is significantly less susceptible to delay, especially memory blocking delays encountered by daemons running on other nodes. The switching of protocols is accompanied by controlled grace periods for needed responses. This messaging protocol flexibility is also adapted for use as a mechanism for controlling the deliberate activities of node addition (birth) and node deletion (death).

Abstract: The determination of node and/or adapter liveness in a distributed network data processing system is carried out via one messaging protocol that can be assisted by a second messaging protocol which is significantly less susceptible to delay, especially memory blocking delays encountered by daemons running on other nodes. The switching of protocols is accompanied by controlled grace periods for needed responses. This messaging protocol flexibility is also adapted for use as a mechanism for controlling the deliberate activities of node addition (birth) and node deletion (death).

Abstract: A network having a plurality of nodes is reconfigured to reflect a change in topology of the network. In particular, upon receiving a reconfiguration request, each node enters a quiescent state for a predetermined period of time sufficient to allow at least one other node to also enter a quiescent state. Then, upon termination of the quiescent state, the node is reconfigured to reflect the change in the topology of the network without having to check with any other nodes of the network. In other embodiments, the predetermined period of time is sufficient to allow currently executing protocols to complete execution as well as to allow the transmission of reconfiguration requests for propagating reconfiguration in the network.