Abstract: A service module that provides for discovery of one or more network interfaces connecting a prospective remote procedure call (RPC) client, facilitates the provision of RPC programs in a network including multi-horned systems. When a request for a network address to an RPC application providing an RPC program is received from the RPC client, the RPC bind daemon discovers from the module, using the client response address, over which interface(s) the client is accessible. The daemon then selects an address of a network path to the RPC application that the prospective client can access and returns the corresponding network address. The service module monitors the network stack for RPC get address requests and builds tables of client address entries with corresponding network interface identifiers. The entries are retired according to an aging policy.

Abstract: Communication between nodes on distinct physical computer systems typically involves fragmentation of packets, such that packet size complies with a communication protocol's specified maximum transmission unit (MTU). However, communications between logical partitions on the same computer system (“virtual nodes”) do not have to comply with a MTU. A computer system can handle packet sizes for intra-system communications between virtual nodes larger than the MTU. Functionality can be implemented to determine that a packet's source and destination are virtual nodes on the same physical machine. This can enable the system to virtually transfer packets for intra-system communication without fragmentation.

Abstract: In a method for regulating network bandwidth in a virtualized computer environment, a computer having a hypervisor program receives a request from a first virtual client to transmit data. In response, the computer transfers the data from a memory of the first virtual client to a memory of a virtual server. The computer receives an error notification from a shared virtual network adapter of the virtual server, indicative of insufficient network bandwidth available to transmit the data. In response, the computer notifies the first virtual client that insufficient network bandwidth is available to transmit the data.

Abstract: A method, programmed medium and system are provided for preventing the denial of file system access to a plurality of clients accessing a NFS server. In one example, an NFS server is configured to listen on a server port. The server runs a separate daemon which “watches” client requests as they are received at the NFS server. The server processing system tracks the number of times a client sends consecutive TCP zero-window packets in response to a data packet from the server. If the number of zero-window packets crosses a user-defined threshold, then a routine is called to stop responding to that client using a backoff algorithm. When the server reaches a point where the number of available threads or any other relevant resource dips below a user-defined threshold, the server process starts terminating connections to the clients starting from the ones with the oldest entry in the table.

Abstract: A method identifies a network socket on a machine by assigning a non-IP address socket anchor and a port number to the network socket. A socket anchor may comprise a globally unique number. In some embodiments, a socket anchor comprises a number having a preselected number of bits. The number having the preselected number of bits may comprise a selected number associated with the machine concatenated with a number of randomly generated bits. The number of bits of the selected number plus the number of randomly generated bits is equal to the preselected number of bits. In some embodiments, the selected number associated with the machine is a Media Access Control (MAC) address of a network interface associated with the machine.

Abstract: A method, system, and computer program product for an improved virtualized operating system environment file-system are provided in the illustrative embodiments. A computer receives a write request for a part in the virtualized operating system environment file-system. The computer determines whether the part in the virtualized operating system environment file-system is a link to a second part in a host file-system. The computer, responsive to the part in the virtualized operating system environment file-system being the link, replaces the link with content of the second part the content replacing the link forming a writable copy of the part.

Abstract: A system identifies a network socket on a machine by assigning a non-IP address socket anchor and a port number to the network socket. A socket anchor may comprise a globally unique number. In some embodiments, a socket anchor comprises a number having a preselected number of bits. The number having the preselected number of bits may comprise a selected number associated with the machine concatenated with a number of randomly generated bits. The number of bits of the selected number plus the number of randomly generated bits is equal to the preselected number of bits. In some embodiments, the selected number associated with the machine is a Media Access Control (MAC) address of a network interface associated with the machine.

Abstract: A network communication device can implement configurable network socket retransmission timeout parameters on a per socket basis. In one embodiment, it is determined, at a first network device, whether to define a network socket with a custom or a default retransmission timeout value to transmit data to a second network device. In response to determining to define the network socket with the custom retransmission timeout value, the network socket is defined with the custom retransmission timeout value, the data is transmitted to the second network device, and it is determined whether response data is received from the second network device prior to expiration of a time period associated with the custom retransmission timeout value. In response to determining that the response data is not received from the second network device prior to the expiration of the corresponding time period, the data is retransmitted to the second network device.

Abstract: A method, system, and computer program product for a self-adjusting application heartbeat management process are provided in the illustrative embodiments. A first application receives from a second application, a response message in response to a heartbeat message. Information is identified in the response message usable for computing a delay in a future response message for a future heartbeat message, such that the information communicates to the first application a system condition existing in the second data processing system where the second application is executing. A response time is adjusted using the information to form a modified response time. The future response message is received after the response time.

Abstract: A computer implemented method monitors activity within a device driver layer of a computer. An arrival rate is identified within a device driver for the node. The arrival rate is a rate at which packets arrive at a network adapter of the node from all other nodes within a network. If the arrival rate exceeds at least one threshold, the node undergoes a state change. The at least one threshold delineates between a plurality of states for the node.

Abstract: A computer implemented method, a tangible computer medium, and a data processing system are provided for waking a blade server from an operational state of reduced power. When server blade enters the state of reduced power, a service firmware configures a multi-port blade switch of the server blade to direct incoming packets to the service firmware. The service firmware then polls for receipt of a Wake-on-Lan magic packet. When the Wake-on-Lan magic packet is received by the service firmware, the service firmware reconfigures the multi-port blade switch to direct incoming packets to a network interface card of the server blade. The service firmware then initiates a reboot of the server blade.

Abstract: A method includes receiving a command to migrate a workload partition from a source machine to a target machine. The source machine and the target machine are communicatively coupled to a first subnetwork and a second subnetwork, respectively. The workload partition has a source network address defined by network addressing of the first subnetwork. The method also includes determining a socket connection providing network communication between the workload partition and a host. The method includes notifying the host that the workload partition is migrating from the source machine to the target machine, wherein in response to the notifying the host is on alert to receive, through a network tunnel communication, an identification of a target network address that is assigned to the workload partition after the workload partition is migrated to the target machine. The workload partition is migrated from the source machine to the target machine.

Abstract: A network device can implement configurable socket aggregation to enable segmentation offload in the network device. In one embodiment, it is determined, at the network device, to create a network socket for an application of the network device to initiate a network connection for the application. Socket aggregation parameters are determined for the network socket associated with the application. The network socket is defined based, at least in part, on the socket aggregation parameters. A plurality of packets received from the application associated with the network socket are aggregated. It is determined, based on said aggregating the plurality of packets, whether at least one aggregation limit associated with the socket aggregation parameters is reached. An aggregate packet is provided to a network adapter of the network device to perform segmentation offload in response to said determining that at least one aggregation limit associated with the socket aggregation parameters is reached.

Abstract: In a computer system having memory, at least one processor and a physical input-output adapter, the at least one processor generates logical partitions, including local logical partitions and an input-output logical partition. The logical partitions have respective local virtual adapters. The input-output logical partition has a shared virtual adapter configured to communicate with the physical input-output adapter, such that a plurality of the local logical partitions share the physical input-output adapter via the shared virtual adapter. The at least one processor provides communication for ones of the local virtual adapters of the local logical partitions directly with the physical input-output adapter by a hypervisor.

Abstract: Data processing workload control in a data center is provided, where the data center includes computers whose operations consume power and a workload controller composed of automated computing machinery that controls the overall data processing workload in the data center. The data processing workload is composed of a plurality of specific data processing jobs, including scheduling, by the workload controller in dependence upon power performance information, the data processing jobs for execution upon the computers in the data center, the power performance information including power consumption at a plurality of power-conserving states for each computer in the data center that executes data processing jobs and dispatching by the workload controller the data processing jobs as scheduled for execution on computers in the data center.

Abstract: Provided is reporting session information for a session upstream from a server. A data processing system receives a session handshake from a first client for a session between the server and the first client. The system receives a session-descriptor for a session between a second client and the first client before handling a nested session. The system determines whether a user has made an upstream session request. The system obtains session data from an upstream data structure, responsive to a determination that the user has made an upstream session request. The system renders the session data based on the upstream session request.

Abstract: User space applications can utilize custom network protocol timers. A registration request is received from an application to register a custom timer. Responsive to receiving the registration request, a handle is created. The handle is a pointer to be used by the application to reference the custom timer. The handle is forwarded to the application. When a custom timer is required, a request to use a custom timer is received from an application. The kernel is then requested to start the custom timer. A determination is then made as to whether a receipt confirmation is received from the kernel before expiration of the custom timer.

Abstract: A computer implemented method, a tangible computer readable medium, and a data processing system intelligently propagate link status information received by a blade server to the various ports of an embedded multi-port switch. The link status of a switch port in an external switch module can be communicated to the operating systems of individual blade servers that are affected by that link status. When an external switch module is unplugged from a server blade chassis, the bus controller broadcasts a link down event, such as a link down interrupt, to the individual server blades where it is received by the embedded multi-port switch for those server blades. The embedded multi-port switch translates the link down interrupt into a hardware link down event, and forwards the hardware link down event to the other elements connected to the embedded multi-port switch.

Abstract: A system for consolidating TCP ports. In response to initiating a connection to a hidden port via a network, a TCP in TCP packet is created. Then, the TCP in TCP packet is sent to the hidden port via the network via a network visible port.

Abstract: A service module that provides for discovery of one or more network interfaces connecting a prospective remote procedure call (RPC) client, facilitates the provision of RPC programs in a network including multi-horned systems. When a request for a network address to an RPC application providing an RPC program is received from the RPC client, the RPC bind daemon discovers from the module, using the client response address, over which interface(s) the client is accessible. The daemon then selects an address of a network path to the RPC application that the prospective client can access and returns the corresponding network address. The service module monitors the network stack for RPC get address requests and builds tables of client address entries with corresponding network interface identifiers. The entries are retired according to an aging policy.