International Business Machines Corporation

Steven Wade Hunter

Renato John Recio

William Gavin Holland

William Todd Boyd

Madeline Vega

Steven Mark Thurber

Douglas Morgan Freimuth

Richard Edwin Harper

Gary Roy Shippy

Tzvetelina B Battestilli

David J Bradley

Terry Lee Nelms

Terry L Nelms, Ii

Charles Steven Lingafelt

William Joseph Piazza

Gregory Brian Pruett

Simon C Chu

Thomas Dixon Pahel, Jr

Harry Cheselka

William Paul Zeggert

Kalyanaraman Vaidyanathan

John Wagner Yarbrough

James Gregory Mulkey

Steven W Thurber

Douglas M Fremiuth

David John Bradley

A method, switch, and/or computer program product routes IP packet flows. An Ethernet switch receives an IP packet flow. Each of the packets in the IP packet flow has a header that contains a same 5-tuple. A load balancing control engine determines whether servers in a group of servers are balanced in their utilization according to 5-tuple redirection rules contained in the load balancing control engine. In response to the load balancing control engine determining, according to the 5-tuple redirection rules, that the servers are balanced, the Ethernet switch routes the IP packet flow to the servers. In response to the load balancing control engine determining that the servers are unbalanced, the load balancing control engine instructs the Ethernet switch to redirect the IP packet flow to a server that is relatively less busy than other servers.

Load-balancing via modulus distribution and TCP flow redirection due to server overload

A method, system, and/or computer program product steers Internet Protocol (IP) packet fragments. A switch receives a first IP packet fragment that contains a 3-tuple in its header. In response to determining that the first IP packet fragment is not a lead packet fragment in the series of IP packet fragments, the first IP packet fragment is pushed onto a data stack. The switch subsequently receives a second IP packet fragment that contains a 5-tuple, which includes the 3-tuple from the first IP packet fragment plus a source port and destination port used by the second IP packet fragment. The 3-tuple is mapped to the 5-tuple in a fragmentation table, thus enabling both the first IP packet fragment and the second IP packet fragment to be steered to the destination port to which the second IP packet fragment is being sent.

Steering fragmented IP packets using 5-tuple based rules

A method, system and/or computer program product route IP packet flows. An Ethernet switch is coupled to a load balancing control engine, which contains load balancing logic that is logically isolated from the Ethernet switch. The Ethernet switch, which routes IP packet flows to servers, receives an IP packet flow. The load balancing control engine determines if the servers are balanced in their workloads. In response to the load balancing control engine determining that the servers are balanced, the Ethernet switch routes the IP packet flow to the servers without the Ethernet switch directly receiving any feedback from the servers regarding their workloads. In response to the load balancing control engine determining that the servers are unbalanced, the load balancing control engine instructs the Ethernet switch to redirect the IP packet flow to a server that is relatively less busy than other servers.

A method, system and/or computer program steer internet protocol (IP) packet fragments that are components of a series of IP packet fragments. A switch receives an IP packet fragment. In response to determining that the fragment is not a lead packet fragment in a series of IP packet fragments that make up an original IP packet, the IP packet fragment is pushed onto a data stack. The switch then receives an IP packet fragment which is determined to be the lead packet fragment in a series of IP packet fragments. The IP 5-tuple from the lead packet fragment is parsed to steer all fragments in the series to a destination port.

A computer-implemented method, apparatus, and computer usable program code are disclosed for migrating a virtual adapter from a source physical adapter to a destination physical adapter in a data processing system where multiple host computer systems share multiple adapters and communicate with those adapters through a PCI switched-fabric bus. The virtual adapter is first caused to stop processing transactions. All in-flight transactions that are associated with the virtual adapter are then captured. The configuration information that defines the virtual adapter is moved from the source physical adapter to the destination physical adapter. The in-flight transactions are then restored to their original locations on the destination virtual adapter. The virtual adapter is then restarted on the destination physical adapter such that the virtual adapter begins processing transactions.

Method, apparatus, and computer usable program code for migrating virtual adapters from source physical adapters to destination physical adapters

A method, mechanism and computer usable medium is provided for distributing I/O fabric errors to the appropriate root nodes in a multi-root environment. The case where the I/O fabric is attached to more than one root node and where each root can potentially share with the other roots the I/O adapter (IOA) resources which are attached to the I/O is addressed. Additionally, a method, mechanism and computer usable medium is provided by which errors detected in an I/O fabric may be routed to all root nodes which may be affected by the error, while not being reported to the root nodes that will not be affected by those errors. In particular, distributed computing system which uses the PCI Express protocol to communicate over the I/O fabric is addressed.

Broadcast of shared I/O fabric error messages in a multi-host environment to all affected root nodes

Routing between multiple hosts and adapters in a PCI environment is provided by a method and system. A Destination Identification (DID) field is inserted in a field of the PCI bus address (PBA) of transaction packets dispatched through PCI switches. A particular DID is associated with a particular host or system image, and thus identifies the physical or virtual end point of the packets. The method and system may track connections such that when particular host of a root node becomes connected to a specified switch, a PCI Configuration Master (PCM), residing in one of the root nodes, is operated to enter a destination identifier or DID into a table. The DID is then inserted in the PBA of packets directed through the specified switch from the particular host to one of the adapters.

Creation and management of routing table for PCI bus address based routing with integrated DID

A method and apparatus is provided for routing error messages in a distributed computer system comprising multiple root nodes, and further comprising one or more PCI switches and one or more I/O adapters, wherein each root node includes one or more system images. In one useful embodiment, a method is provided for routing I/O error messages to root nodes respectively associated with the errors contained in the messages. The method includes detecting occurrence of an error at a specified one of the adapters, wherein the error affects one of the system images, and generating an error message at the specified adapter. The method further comprises routing the error message from the specified adapter to the particular root node that includes the affected system image. The error message is then selectively processed at the particular root node, in order to identify the affected system image. Usefully, the step of routing the error message includes using a bus/device/function number associated with the error, together with a routing table located in one of the PCI switches, to route the error message to the correct root node and system image.

Method of routing I/O adapter error messages in a multi-host environment

A computer-implemented method, apparatus, and computer program product are disclosed in a data processing environment that includes host computer systems that are coupled to adapters utilizing a switched fabric for routing packets between the host computer systems and the adapters. A unique destination identifier is assigned to one of the host computer systems. A portion of a standard format packet destination address is selected. Within a particular packet, the portion is set equal to the unique identifier that is assigned to the host computer system. The particular packet is then routed through the fabric to the host computer system using the unique destination identifier.

Method, apparatus, and computer program product for routing packets utilizing a unique identifier, included within a standard address, that identifies the destination host computer system

A computer-implemented method, apparatus, and computer program product are disclosed for routing error messages in a multiple host computer system environment to only those host computer systems that are affected by the error. The environment includes multiple host computer systems that share multiple devices utilizing a switched fabric. An error is detected in one of the devices. Routing tables that are stored in fabric devices in the fabric are used to identify ones of the host computer systems that are affected by the error. An error message that identifies the error is routed to only the identified ones of the host computer systems.

Routing of shared I/O fabric error messages in a multi-host environment to a master control root node

In a distributed computer system having multiple root nodes, a challenge protocol is provided, for use in determining or confirming the root node in which a PCI Configuration Manager (PCM) actually resides. This node is referred to as the master node. The challenge procedure is activated whenever the identity of the PCM, which is determined by the root node in which it resides, appears to be uncertain. The challenge procedure resolves this uncertainty, and enables the PCM to continue to configure routings throughout the system. In a useful embodiment, a method is directed to a distributed computer system of the above type which is further provided with PCI switches and with adapters that are available for sharing by different nodes. The method includes the steps of selecting a first one of the root nodes to be master root node, and operating the first root node to query the configuration space of a particular one of the PCI switches. The method further includes detecting information indicating that a second root node is considered to be the master root node for the particular switch. A challenge protocol is implemented in response to this detected information, to seek confirmation that the first root node is the master root node. The configuration space querying procedure is continued if the first root node is confirmed to be the master root node, and is otherwise aborted.

Method for confirming identity of a master node selected to control I/O fabric configuration in a multi-host environment

A computer-implemented method, apparatus, and computer program product are disclosed for bus/device/function (BDF) translation and routing of communications packets through a fabric that utilizes PCI switches. Identifiers are included in communications packets that are routed between a host and an I/O adapter using a PCI fabric to which the host and the I/O adapter are coupled. Destination identifiers that are included in first communications packets that are received by edge switches, which are connected directly to said host or directly connected to said I/O adapter, are translated before routing the communications packets out of the edge switches. Second communications packets that are received by internal switches, which are not directly connected to the host or directly connected to the I/O adapter, are routed without translating destination identifiers that are included in the second communications packets.

Bus/device/function translation within and routing of communications packets in a PCI switched-fabric in a multi-host environment utilizing multiple root switches

System and method for managing routing of data in a distributed computing system, such as a distributed computing system that uses PCI Express protocol to communicate over an I/O fabric. A physical tree that is indicative of a physical configuration of the distributed computing system is determined, and a virtual tree is created from the physical tree. The virtual tree is then modified to change an association between at least one source device and at least one target device in the virtual tree. A validation mechanism validates the changed association between the at least one source device and the at least one target device to enable routing of data from the at least one source device to the at least one target device.

Creation and management of destination ID routing structures in multi-host PCI topologies

A method is directed to use of a master root node, in a distributed computer system provided with multiple root nodes, to control the configuration of routings through an I/O switched-fabric. One of the root nodes is designated as the master root node or PCI Configuration Manager (PCM), and is operable to carry out the configuration while each of the other root nodes remains in a quiescent or inactive state. In one useful embodiment pertaining to a system of the above type, that includes multiple root nodes, PCI switches, and PCI adapters available for sharing by different root nodes, a method is provided wherein the master root node is operated to configure routings through the PCI switches. Respective routings are configured between respective root nodes and the PCI adapters, wherein each of the configured routings corresponds to only one of the root nodes. A particular root node is enabled to access each of the PCI adapters that are included in any configured routing that corresponds to the particular root node. At the same time, the master root node writes into a particular root node only the configured routings that correspond to the particular root node. Thus, the particular root node is prevented from accessing an adapter that is not included in its corresponding routings.

Growing community of inventors

Raleigh, NC, United States of America

Steven Wade Hunter