Abstract: A computer program product, apparatus, and method for handling early termination of an I/O operation at a channel subsystem in an I/O processing system are provided. The computer program product includes a tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method. The method includes receiving a request to terminate an I/O operation, and transmitting an abort command to a control unit in communication with the channel subsystem in response to receiving the request to terminate the I/O operation. The method also includes transmitting a purge path command to purge a path associated with the I/O operation, where the purge path command includes an error code identifying the request to terminate the I/O operation.

Abstract: A computer program product, apparatus, and method for providing exception condition feedback at a control unit to a channel subsystem in an I/O processing system are provided. The computer program product includes a tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method. The method includes receiving a command message at the control unit from the channel subsystem, and detecting an exception condition in response to unsuccessful execution of at least one command in the command message. The method further includes identifying a termination reason code associated with the exception condition, writing the termination reason code to a response message, and sending the response message to the channel subsystem.

Abstract: A system, method and computer program product for dynamically debugging a multi-node network comprising an infrastructure including a plurality of devices, each device adapted for communicating messages between nodes which may include information for synchronizing a timing clock provided in each node. The apparatus comprises a plurality of probe links interconnecting each node with a probe device that monitors data included in each message communicated by a node. Each probe device processes data from each message to determine existence of a trigger condition at a node and, in response to detecting a trigger condition, generates a specialized message for receipt by all nodes in the network. Each node responds to the specialized message by halting operation at the node and recording data useful for debugging purposes. In this manner, debug information is collected at each node at the time of a first error detection and collected dynamically at execution time without manual intervention.

Abstract: I/O measurement data for channels attached to logical control unit queues is obtained related to a plurality of logical control unit queues. A store secondary queue measurement data instruction specifies a range of queues for which extended secondary measurement blocks derived from the I/O measurement data are stored at a memory address specified by the store secondary queue measurement data instruction.

Abstract: A network system supports multiple network communication protocols. In one embodiment, network device driver software provides a “Fibre Channel over Ethernet” communication capability and methodology. Device driver software manages a Fibre Channel to Ethernet and Ethernet to Fibre Channel address translation in real time for data packet communications in the network system. Different embodiments of the disclosed network system include multiple name servers and network device driver software that together provide multiple adapter name discovery methodologies. In one embodiment, the adapter name discovery methodologies include port name discovery and adapter attributes discovery.

Abstract: A network system supports multiple network communication protocols. In one embodiment, network device driver software provides a “Fibre Channel over Ethernet” communication capability and methodology. Device driver software manages a Fibre Channel to Ethernet and Ethernet to Fibre Channel address translation in real time for data packet communications in the network system. Different embodiments of the disclosed network system include multiple name servers and network device driver software that together provide multiple adapter name discovery methodologies. In one embodiment, the adapter name discovery methodologies include port name discovery and adapter attributes discovery.

Abstract: A network system supports multiple network communication protocols. In one embodiment, network device driver software provides a “Fibre Channel over Ethernet” communication capability and methodology. Device driver software manages a Fibre Channel to Ethernet and Ethernet to Fibre Channel address translation in real time for data packet communications in the network system. Different embodiments of the disclosed network system include multiple name servers and network device driver software that together provide multiple adapter name discovery methodologies. In one embodiment, the adapter name discovery methodologies include port name discovery and adapter attributes discovery.

Abstract: Disclosed are a method and system for calculating clock offset and skew between two clocks in a computer system. The method comprises the steps of sending data packets from a first processing unit in the computer system to a second processing unit in the computer system, and sending the data packets from the second processing unit to the first processing unit. First, second, third and fourth time stamps are provided to indicate, respectively, when the packets leave the first processing unit, arrive at the second processing unit, leave the second processing unit, and arrive at the first processing unit. The method comprises the further steps of defining a set of backward delay points using the fourth time stamps, and calculating a clock offset between clocks on the first and second processing units and clock skews of said clocks using said set of backward delay points.

Abstract: Disclosed is a method for calculating clock offset and skew between two clocks in a computer system. The method comprises the steps of sending data packets from a first processing unit in the computer system to a second processing unit in the computer system, and sending the data packets from the second processing unit to the first processing unit. First, second, third and fourth time stamps are provided to indicate, respectively, when the packets leave the first processing unit, arrive at the second processing unit, leave the second processing unit, and arrive at the first processing unit. The method comprises the further steps of defining a set of backward delay points using the fourth time stamps, and calculating a clock offset between clocks on the first and second processing units and clock skews of said clocks using said set of backward delay points.

Abstract: Server time protocol (STP) messages and methods of exchange thereof are provided for facilitating synchronization of processing units of a timing network. The STP messages include exchange time parameters (XTP) commands and responses, and STP control (STC) commands and responses. XTP message exchange processing includes: generating an XTP message command at a first processing unit including a command transmit timestamp field set by the first processing unit and a command receive timestamp field which is unset by the first processing unit; transmitting the XTP message command to a second processing unit; setting the command receive timestamp field in the XTP command with the time the XTP command is received at the second processing unit; and generating an XTP message response at the second processing unit, the message response including the command transmit timestamp set by the first processing unit and the command receive timestamp set by the second processing unit.

Abstract: Server time protocol (STP) messages and methods of exchange thereof are provided for facilitating synchronization of processing units of a timing network. The STP messages include exchange time parameters (XTP) commands and responses, and STP control (STC) commands and responses. XTP message exchange processing includes: generating an XTP message command at a first processing unit including a command transmit timestamp field set by the first processing unit and a command receive timestamp field which is unset by the first processing unit; transmitting the XTP message command to a second processing unit; setting the command receive timestamp field in the XTP command with the time the XTP command is received at the second processing unit; and generating an XTP message response at the second processing unit, the message response including the command transmit timestamp set by the first processing unit and the command receive timestamp set by the second processing unit.

Abstract: Recovery is provided in a timing network. A configuration is defined for that network, and in that configuration, an active primary server is identified that provides a clock source for the network. Additionally, an alternate server is identified that can perform the role of the active primary server, should the active primary server fail. In response to a failure of the primary server, the alternate server detects the failure and performs takeover of the primary server.

Abstract: A stratum-1 configuration for a timing network is defined. The stratum-1 configuration includes a single active stratum-1 server usable in ensuring that the servers in the network use the same primary reference time to synchronize their clocks. The servers in the network are synchronizing to the same root primary reference time and synchronization accuracy is not dependent on the quality of an external time source or of the existence of an external time source at the stratum-1 server.

Abstract: A technique for establishing a logical path between two servers in a coordinated timing network of a processing environment is provided. The technique includes the exchange of command and response message pairs by a server and an attached server, via a physical link. The server transmits a command message to an attached server to establish a server-time-protocol (STP) logical path and receives a response from the attached server. The technique also includes the server receiving a request transmitted by the attached server to establish an STP logical path to the server and transmitting a response to the attached server's request. A logical path between the server and the attached server is established if the attached server's response indicates that the server's request was accepted by the attached server and if the server's response indicates that the attached server's request was accepted by the server.

Abstract: A timing network is provided that includes a plurality of servers. The servers of the network obtain information used to maintain the servers in time synchronization, thus ensuring the integrity of the servers.

Abstract: A timing network is provided that includes a plurality of servers. The servers of the network obtain information used to maintain the servers in time synchronization, thus ensuring the integrity of the servers.

Abstract: A protocol for communicating with the timing facility used in a data processing network to provide synchronization is provided via the execution of a machine instruction that accepts a plurality of commands. The interaction is provided through the use of message request blocks and their associated message response blocks. In this way timing parameters may be determined, modified and communicated. This makes it much easier for multiple servers or nodes in a data processing network to exist as a coordinated timing network and to thus more cooperatively operate on the larger yet identical data files.

Abstract: An Input/output (I/O) measurement block facility is provided that creates subchannel measurement blocks (comprising device busy values) related to performance of an I/O operation of a subchannel, wherein a device busy time value is a sum of time intervals when the subchannel is device busy during an attempt to initiate any one of a start function or a resume function at the subchannel.

Abstract: In a networked data processing system, the updating of timing parameters is carried out via a process in which the detection of the loss of communications with the network is not immediately employed as an indication of parameter invalidity but rather the process employs a system specific delay which permits actions such as server or link recovery to occur without necessitating the declaration of timing parameter invalidity.

Abstract: An input/output subsystem is configured as a plurality of input/output subsystem images, each of which appears to a program as an independent input/output subsystem. In response to an operating system image submitting an input/output (I/O) request requesting access to an input/output subsystem image, a determination is made as to whether the operating system image is authorized to access the input/output subsystem image. In response to the access being authorized, the I/O request is authorized.