Creation and migration of distributed streams in clusters of networked computers

In a multicomputer system capable of STREAMS operation, the system which including a cluster of two or more nodes including a local node and a remote node connected via a data communications interconnect subsystem, each node including a computer having one or more system processor units, local memory, and an input/output subsystem, an operating system running on each of the system processor units in the cluster, the operating system including a file system and a STREAMS message-passing mechanism having an open function for creating a stream head and a driver with bidirectional communications, client/server applications and services, a software application operative on the system processor unit of at least one node under control of the operating system to perform a task or solve a problem, a method of creating a distributed STREAMS data structure, the method comprising:

• initiating a controlling thread on each node in the cluster, including determining where STREAMS drivers are located within each node and determining which facilities are associated with each driver;
• setting a flag in the STREAMS mechanism on each node in the cluster indicating that clustering is enabled;
• assigning a file name uniquely representing a specific driver on a node in the cluster, the file name encoding a major number table identification for each driver and a minor number parameter for selectably identifying at least one of a driver on a remote node and local facilities on the local node;
• communicate the file names of the drivers on each node to the other nodes in the cluster through the file system;
• running the STREAMS open function to open the driver for the file, looking at the file name to ascertain that it is a clustering facility and, if so, passing the initial major number and minor number to the controlling thread;
• the controlling thread using the major and minor numbers to look up the represented devices and facilities and deriving a new major and minor number and passing those numbers along with a set of facilities identifiers back to the STREAMS mechanism;
• and
• if the initial major number and minor number pertain to facilities on the remote node, the STREAMS mechanism in the local node opening a STREAMS software interconnect driver (S-ICS) on the local node and the S-ICS driver communicating an open request to the controlling thread on the remote node;
• the controlling thread being operative upon initialization to establish a STREAMS software interconnect driver (S-ICS) on the local node;
• the controlling thread on the remote node performing an internal STREAMS open to create on the remote node a distributed STREAMS instance of the STREAMS data structure on the local node.

A method for migrating at a portion of a stack on multicomputer system capable of distributed operation, from a first node to a second node, wherein the stack contains a set of function pointers for controlling execution of module and driver functions, the method comprising the steps of:

• issuing a system call requesting migration;
• freezing the stack to prevent message flow into and out of the stack;
• marshaling all information necessary to replicate the portion;
• delivering the marshaled information to a control thread on the second node;
• recreating the portion on the second node;
• releasing the remaining portion of the stack;
• and
• activating a communications route between the portion on the second node and the remaining portion on the first node.

A multicomputer system that is capable of distributed operations and includes a plurality of nodes connected via communications interconnects, the system is running an operating system which uses a messaging mechanism in a portion of its operations, the system comprising:

• a plurality of controlling threads, with one controlling thread associated with each node of the plurality of nodes, wherein each controlling thread is resident on a kernel of its associated node, and each controlling thread managing the messaging mechanism resident within its node;
• a plurality of stacks, wherein each stack is capable of containing a set of function pointers for controlling execution of module and driver functions useable by the plurality of nodes;
• a plurality of a physical interconnection drivers (PID), with one PID associated with each node of the plurality of nodes, wherein each PID which provides communication facilities between its node and the remaining nodes of the plurality of nodes, each PID is under the control of the control thread of the same node;
• a plurality of a software interconnection drivers (SID), with one SID associated with each node of the plurality of nodes, wherein each SID allows communications between the PID of its associated node and at least one other component of its node, each SID is under the control of the control thread of the same node;
• and
• a plurality of preview functions, with at least one preview function associated with each node of the plurality of nodes, wherein each preview function is a policy regarding a system wide facility, the controlling thread of the associated node will use the at least one preview function to modify operations of the associated stack.