The “worm” programs—early experience with a distributed computation

ABSTRACT

The “worm” programs were an experiment in the development of distributed computations: programs that span machine boundaries and also replicate themselves in idle machines. A “worm” is composed of multiple “segments,” each running on a different machine. The underlying worm maintenance mechanisms are responsible for maintaining the worm—finding free machines when needed and replicating the program for each additional segment. These techniques were successfully used to support several real applications, ranging from a simple multimachine test program to a more sophisticated real-time animation system harnessing multiple machines.

REFERENCES

• 1: Boggs, D.R., Shoch, J.F., Taft, E.A., and Metcalfe, R.M. PUP: An internetwork architecture. IEEE Trans. Commun. 28, 4 (April 1980). Describes the Pup internetwork architecture, used to tie together over 1,200 machines on several dozen different networks.
• 2: Dalai, Y.K. Broadcast protocols in packet switched computer networks. Tech. Rep. 128, Stanford Digital Syst. Lab., Stanford, Calif., April 1977. Discussion of alternative techniques for broadcast addressing.
• 3: Yogen K. Dalal , Robert S. Printis, 48-bit absolute internet and Ethernet host numbers, Proceedings of the seventh symposium on Data communications, p.240-245, October 27-29, 1981, Mexico City, Mexico
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• 5: Shoch, J.F. lnternetwork naming, addressing, and routing. Proc. 17th IEEE Comp. Soc. Int. Conf. (Compcon Fall '78), Washington, D.C., Sept. 1978.General discussion of addressing modes, including the use of multicast addressing.
• 6: Shoch, J.F. Local Computer Networks. McGraw-Hill, New York (in press). A survey of alternative local networks and a detailed description of the Ethernet local network.
• 7: Shoch, J.F., and Hupp, J.A. Performance of an Ethernet local network-a preliminary report. Local Area Comm. Network Symp., Boston, Mass., May 1979 (reprinted in the Proc. 20th 1EEE Comp. Soc. Int. Conf. (Compcon Spring '80), San Francisco, Calif., Feb. 1980). Description of the measured performance of the Ethernet.
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• 9: Shoch, J.F., Dalai, Y.K., Crane, R.C., and Redell, D.D. Evolution of the Ethernet local computer network. Xerox Tech. Rep. OPD-T81-02, Palo Alto, Calif., Sept. 1981. The basic paper on the revised and improved Ethernet Specification, including comparisons with the original Experimental Ethernet.
• 10: Thacker, C.P., McCreight, E.M., Lampson, B.W., Sproull, R.F., and Boggs, D.R. Alto: A personal computer. In Computer Structures: Principles and Examples, 2nd edition, Siewiorek, Bell, and Newell, Eds., McGraw-Hill, New York, 1982, 549-572. Describing the Alto computer--a high-performance, single-user machine--which was used for running the worm programs.

INDEX TERMS

Primary Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS

Additional Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS

General Terms:
Design, Experimentation

Keywords:
Ethernet local network, Pup internetwork architecture, multimachine programs