Multicomputer system

• US 6,424,988 B2
• Filed: 11/24/1997
• Issued: 07/23/2002
• Est. Priority Date: 02/19/1997
• Status: Expired due to Term

• Current Assignee: Unisys Corporation
• Original Assignee: Unisys Corporation
• Inventors: Lurndal, Scott
• Primary Examiner(s): COURTENAY III, ST JOHN
• Application Number:
  US08/977,222
• Publication Number:
  US 20020016863A1
• Time in Patent Office: 1,702 Days
• Field of Search: 709/200-332, 709/100-106, 711/147, 707/2, 707/10, 707/204, 707/200-206, 717/100-178
• US Class Current: 718/106
• CPC Class Codes: G06F 11/2025 using centralised failover control functionality
• CPC Class Codes: G06F 11/203 using migration
• CPC Class Codes: G06F 11/2043 where the redundant components share a common memory address space
• CPC Class Codes: G06F 9/4843 by program, e.g. task dispatcher, supervisor, operating system
• CPC Class Codes: G06F 9/526 Mutual exclusion algorithms

Abstract

A method is provided for responding to a computer system call requesting creation of such new process in a multicomputer system which includes multiple sites, each site including a local processor and local memory, and wherein the multicomputer system includes a distributed process directory which is distributed across multiple sites such that different site memories include different fragments of the process directory and such that the distributed process directory includes a multiplicity of slots, the method comprising the steps of: creating the new process on a respective site; providing in memory of at least one site a designation of sites for which respective process directory fragments include at least one unallocated slot; selecting a respective site from the designation; and referencing a respective process identification corresponding to the new process in a slot in a respective process directory fragment on the selected site.

Claims

1. A method for responding to a computer system call requesting creation of such new process in a multicomputer system which includes multiple sites, each site including a local processor and local memory, and wherein the multicomputer system includes a distributed process directory which is distributed across multiple sites such that different site memories include different fragments of the process directory and such that the distributed process directory includes a multiplicity of slots, the method comprising the steps of:

creating the new process on a respective site;

providing in memory of at least one site a designation of sites for which respective process directory fragments include at least one unallocated slot;

selecting a respective site from the designation; and

referencing a respective process identification corresponding to the new process in a slot in a respective process directory fragment on the selected site.

2. The method of claim 1 further including:

providing different respective process manager servers operative on different respective sites;

wherein a respective process manager server operative on a first site creates the new process on the first site in response to the system call; and

wherein the step of providing in memory of at least one site a designation of sites involves providing a designation of process manager servers operative on respective sites for which respective process directory fragments include at least one unallocated slot.

3. The method of claim 1 further including:

providing different respective process manager server operative on different respective sites;

wherein a respective process manager server operative on a first site creates the new process on the first site in response to the system call;

wherein the step of providing in memory of at least one site a designation of sites involves providing a designation of process manager servers operative on respective sites for which respective process directory fragments include at least one unallocated slot; and

wherein the step of providing a respective process identification involves a respective second process manager server operative on the selected site associating the respective process identification corresponding to the new process with a slot in a respective process directory fragment on the selected site.

4. The method of claim 1 further including:

providing different respective process manager servers operative on different respective sites;

wherein a respective process manager server operative on a first site creates the new process on the first site in response to the system call;

wherein the step of providing in memory of at least one site a designation of sites involves providing a designation of respective ports that correspond to respective process manager servers operative on respective sites for which respective process directory fragments include at least one unallocated slot; and

wherein the step of selecting a site involves selecting a respective port from the designation of ports.

5. The method of claim 1 further including:

providing different respective process manager servers operative on different respective sites;

wherein a respective process manager server operative on a first site creates the new process on the first site in response to the system call;

wherein the step of providing in memory of at least one site a designation of sites involves providing a designation of respective ports that correspond to respective process manager servers operative on respective sites for which respective process directory fragments include at least one unallocated slot;

wherein the step of selecting a site involves selecting a respective port from the designation of ports; and

wherein the step of referencing a respective process identification involves a respective second process manager server identified by the selected port associating the respective process identification corresponding to the new process with a slot in a respective process directory fragment on the site on which the second process manager server is operative.

6. The method of claim 1 further including:

providing different respective process manager servers operative on different respective sites;

wherein a respective process manager server operative on a first site creates the new process on the first site in response to the system call; and

wherein the step of providing in memory of at least one site a designation of sites involves providing a process group manager server which provides a designation of process manager servers operative on respective sites for which respective process directory fragments include at least one unallocated slot;

wherein the step of selecting a respective site from the designation involves the first process manager server sending a message to the process group server requesting selection of a respective process manager server from the designation; and

wherein the step of referencing involves the process group manager sending a message to the selected process server requesting that a respective process identification corresponding to the new process be associated with a slot in a respective process directory fragment on a respective site on which the selected process manager server is operative.

7. The method of claim 1,

wherein said step of referencing a new process identification involves providing such reference in a process directory structure fragment slot on a site other than the respective site on which the new process is operative.

8. The method of claim 1,

wherein said step of referencing a new process identification involves providing such reference in a process directory structure fragment slot on a site other than the respective site on which the new process is operative;

and including the further step of;

providing a new process structure in site memory on the respective site on which the new process is operative, such new process structure providing a reference to the other site which includes the slot with the reference to the new process identification.

9. The method of claim 1 further including:

providing different respective process manager servers operative on different respective sites;

wherein a respective process manager server operative on a first site creates the new process on the first site in response to the system call;

wherein the step of providing in memory of at least one site a designation of sites involves providing a designation of process manager servers operative on respective sites for which respective process directory fragments include at least one unallocated slot; and

wherein said step of referencing a new process identification involves providing such reference in a process directory structure fragment slot on a site other than the first site; and

including the further step of;

providing a new process structure in site memory on the first site, such new process structure providing a reference to the other site which includes the slot with the reference to the new process identification.

10. A method for creation of a process in a multicomputer system which includes multiple sites interconnected by high speed data links, each site including a local processor and local memory and local serverized operating system which includes a local process manager server addressable through an associated process manager port identifier, the system further including a messaging facility for controlling the transfer of messages between different processes operative on different sites of the system, the method comprising the steps of:

providing a process directory structure distributed across multiple sites such that different site memories include different fragments of the process directory structure, such fragmented process directory structure including a multiplicity of slots for referencing a multiplicity of process port identifiers;

providing a process directory port group structure in site memory of at least one of the sites which references respective port identifiers associated with respective process managers operative on respective sites for which respective process directory fragments include unallocated slots;

providing a process directory port group manager operative on at least one of the sites;

issuing call to a respective process manager server, such call requesting a create a new process operation;

transferring a first message from the respective process manager receiving the call to the process directory port group manager, such first message requesting allocation of a slot;

transferring a second message from the process directory port group manager to a process manager associated with one of the port identifiers stored in the process directory port group structure, such second message requesting to allocate a slot in the process directory fragment of such process manager receiving such second message;

completing the new process creation operation on the site that contains the process manager receiving the call requesting a create a new process operation; and

providing a reference to a new process port identification associated with the new process in a slot of the process directory fragment on the site of process manager receiving the second message.

11. The method of claim 10,

wherein the process directory port group structure does not include the port identifier associated with the process manager receiving the call requesting a create a new process operation; and

wherein said step of providing a reference to a new process port identification involves providing such reference in a process directory structure fragment slot on a site other than the site of the process manager receiving the call requesting a create a new process operation.

12. The method of claim 10,

wherein the process directory port group structure does not include the port identifier associated with the process manager receiving the call requesting a create a new process operation;

wherein said step of providing a reference to a new process port identification involves providing such reference in a process directory structure fragment slot on a site other than the site of the process manager receiving the call requesting a create a new process operation; and

including the further step of;

providing a new process structure associated in site memory with the new process, such new process structure providing a reference to the other site which includes the slot with the reference to the new process port identification.

13. A method of process migration between sites in a multicomputer system which includes multiple sites interconnected by high speed data links, each site including a local processor and local memory a distributed process directory which is distributed across multiple sites such that different site memories include different fragments of the process directory and such that the distributed process directory includes a multiplicity of slots, the method comprising the steps of:

transferring a process, which is operative on a first site and which is referenced in a slot of a respective process directory fragment on the first site, from the first site to a second site; and

maintaining the reference to the transferred process in the slot of the respective process directory fragment on the first site.

14. The method of claim 13 including the further step of:

destroying a copy of the respective transferred process operative on the first site.

15. The method of claim 13 including the further step of:

providing a new process structure associated in second site memory with the transferred process, such new process structure providing a reference to the first site which includes the slot with the reference to the transferred process.