University of Pennsylvania ScholarlyCommons Technical Reports (CIS) Department of Computer & Information Science February 1971 The Design of a Meta-System for Measurement and Simulation of Time-Sharing Computers Andrew S. Noetzel University of Pennsylvania Follow this and additional works at: https://repository.upenn.edu/cis_reports Recommended Citation Andrew S. Noetzel, "The Design of a Meta-System for Measurement and Simulation of Time-Sharing Computers", . February 1971. University of Pennsylvania Department of Computer and Information Science Technical Report No. MS-CIS-71-15. This paper is posted at ScholarlyCommons. https://repository.upenn.edu/cis_reports/803 For more information, please contact [email protected]. The Design of a Meta-System for Measurement and Simulation of Time-Sharing Computers Abstract This report presents the results of a study of a measurement-simulation technique for evaluating modifications ot time-sharing systems. The technique consists of using raw data, obtained by measurement of an operational system, as the input to a simulation model of the variant version of the system. The results of the research are reported in the form of a detailed design of a system that will perform this evaluation. It is called the Meta-System. The Meta-System consists of three parts: event-recording mechanisms in the time sharing system that record a 'system event trace', a pre-processor of the system event trace that decomposes it into independent 'task event traces' and the simulator that accepts these as input. The significant problem in the design of such a system is that of ensuring that the representations of the systems operation (the task event traces) are valid for use by the simulation model. Various solutions for the particular cases of timesharing system operation are provided in the design of each of the three stages of the Meta-System. It is shown that the Meta-System may be designed to extract representations of the time-sharing systems' operation at any one of several levels. These are called the 'levels of Meta-System awareness of system operation'. The extent of the simulation model is specified by the level, as well as the class of modifications that may be evaluated in the model. The particular Meta-System designed in this study was developed to operate with a model time-sharing system, whose features have been abstracted from those of several modern systems. These features include demand paging, multi-tasking, dynamic loading, and a virtual access method. The description of the model system is included in the report. Keywords event analyzer, file structure, input/output simulators, measurement-simulaton, memory allocation, meta- system, random access, simulation, time sharing Comments University of Pennsylvania Department of Computer and Information Science Technical Report No. MS- CIS-71-15. This technical report is available at ScholarlyCommons: https://repository.upenn.edu/cis_reports/803 University of .L'eii~isylvania 'I!KE MOORE SCHOOL OF ~CTR1CA.LENGTNEEliING Philadelphia, Pennsylvania 19104 'l3CHNICA.L REPORT TRE DESIGN OF A ME113CI-SYSTEM FOR MEASUREMENT AND Sj3WlXTION 01' TIME-SHARING COMPTJTEFiS Andrew S. Noetzel February 1971 Submitted to the Office of Naval Research Inf'ormation Systems Branch Arlington, Virginia under Contract ~00014-67-A-0216-0014 Research Project NR 049-153 Reproduction in whole or in part is permitted for any purpose of the United States Government Moore School Report No. 71-15 Security Classification I DOCUMENTCONTROLDATA- R&D 1 (Security classification of title, body of abstract and indexing annofalion must be entered when the overall report is rlnssilied) 1. ORIGINATING ACTIVITY (C~p~rat~d~thor) ZI. REPORT SECURITY CLASSIFICATION The Moore School of Electrical Engineering University of Pennsylvania UN~SSIFIED Phila., Pa. 19104 2b. GROUP I 3. REPORT TITLE I 'DIE DESIGN OF A MEE4-SYSTEM FOR MEASITREDENT AND SIMULClTION OF I TIME SHARING COMKJTERS 4 1 FSCRlPTlVE NOTES (5pe of laport and.inc1usIve dates) Technical Report I 8. AU THOR(S) (Firat name. middle inlttal. last name) Andrew S. Noetzel 6. REPORT DATE 7a. TOTAL NO. OF PAGES 76. NO. OF REFS February 1971 279 128 aa. CONTRACT OR GRANT NO. ga. ORIGINATOR'S REPORT NUMBER(SI I ~00014-67-A-0216-0014 Moore School Report No. 71-15 b. PROJECT NO. 9b. 0 THER REPORT NOIS) (Any other numbers that may be assigned this report) 10. DISTRIBUTION STATEMENT Reproduction in whole or in part is permitted for any purpose of the I U.S. Government. 11. SUPPLEMENTARY NOTES 12. SPONSORING MILITARY ACTIVITY Office of Naval Research Information Systems Branch Arlington, Virginia 13. ABSTRACT This report presents the results of a study of a measurement-simulation tech- nique for evaluating modifications to time-sharing systems. The technique consists of using raw data, obtained by measurement of an operational system, as the input to a simulation model of the variant version of the system. The results of the research are reported in the form of a detailed design of a system that will perform this evaluation. It is called the Meta-System. The Meta-System consists of three parts: event-recording mechanisms in the time sharing system that record a 'system event trace', a pre-processor of the system event trace that decomposes it into independent 'task event traces' and the simulator that 1 accepts these as input. 'Ihe significant problem in the design of such a system is that of ensuring that 1 the representations of the systems operation (the task event traces) are valid for use by the simulation model. Various solutions for the particular cases of time- sharing system operation are provided in the design of each of the three stages of the Meta-System. It is shown that the Meta-System may be designed to extract representations of the time-sharing systems1 operation at any one of several levels. These are called the 'levels of Meta-System awareness of system operation'. The extent of the sitnula- tion model is specified by the level, as well as the class of modifications that may be evaluated in the model. I ( continued next pi@;e) I FORM 1473 (PAGE 1) DD I NOV 65 S/N 01 01 -807-681 1 Security Classification A-31408 S/N 0101-807-6821 Security Classification 4-31409 13. ABSTRACT (continued) The particular Meta-System designed in this study was developed to operate with a model time-sharing system, whose features have been abstracted from those of several modern systems. These features include demand paging, multi-tasking, dynamic loading, and a virtual access method. 5e description of the model system is included in the report. Abstract THE DESIGN OF A META_-SYSTEM FOR MEASLTiUDENT AND SIMJLA.TION 01" Tl.ME-:3.ARIN(; COMPUlCERS !This report presents the ~~ecultsof a study of' a measure- ment- simulation technique for. cvaluatine rr~odificat ions to t i~ne-sharing systems. The technique consist:: 01' using raw data, ohtained by measure- ment of an operational system, a:: the input to rr simulation rnodcl of the variant version of the system. The results of the research are reported in the form of a detailed design of a system that will perform this evaluation. It is called the Meta-System. The Meta-System cons,ists 02 three parts: event-recording mechanisms in the time-sharing system that record a 'system event trace', a pre- processor of the system event trace that decomposes it into independent 'task event traces' and the simulator that accepts these as input. The significant problem in the design of such a system is t'rlat of ensuring that the representations of the systems operation (the task event traces) are valid for use by the simulation model. Various solu- tions for the particular cases of time-sharing cystem operation are provided in the design of each of the three stages of the Meta-System. It is shown that the Meta-System may be designed. to extract representations of the time-sharing systems' opera ti or^ at any one of several levels. These are called the 'levels of Meta-:;ystern awareness of system operation'. The extent of the simulation model ic specified by the level, as well as the class of modifications that may be evaluaterl in the model. The particular Meta-System designed in this study was developed to operate with a model time-sharing system, whose features have been abstracted from those of several modern systems. These features include demand paging, multi-tasking, dynamic loading, and a virtual access method. The description of the model system is included in the report. WLE OF CONTENTS Page Chapter 1: Introduction and Summary 1 The Meta-System 2 Summary of Research Reported 5 Chapter 2: Background, Motivation, and Previous Work 13 Evaluation and Measurement of Time-sharing System Performance Criteria for Evaluating Hatch Processing Systems 13 Quantification of Criteria 15 Fffects of Evaluation in the Development of Batch Processing Systems 16 Difference Between Batch,and Time-Sharing Evaluation 18 Response Time Constraint 19 Intrinsic Problem of Time-sharing Systems 21 Sophistication of System Design 24 Isolation of User Requirements From Hardware 24 Criteria for Time- Sharing Systems 27 Measurement Techniquco Mea ouremcnt of Utilixat iorr Approach to thc Keu:;urcn~c.rlt l'roLlc.~n 33 Vie Meta-System 38 Chapter 3: Overview of Neta-System Desi en 39 The Measurement Function of tile I/lc.ta-Systcm 39 The Evaluation Function of the Ideta- Systern 41 TABLE OF CONTENTS (continued) Functional Description of the Meta-System The Recording Mechanisms The Preprocessor The Simulator Levels of Meta-System