On the twin measure and queueing systems predictability

David Raz*, Hanoch Levy, Benjamin Avi-Itzhak

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Two identical jobs with deterministically identical processing times arrive at a web server simultaneously (Twins), but leave the system thirty seconds apart. Is the service predictable? Is their sojourn time predictable? This issue arises in modern day networking systems such as call centers and web servers as well as in other queueing systems. We propose a novel measure based on the principle that in a predictable system, "twin" jobs should not depart the system very far apart. We analyze this measure for a number of common scheduling policies and compare the results. We compare the results to those of other predictability approaches proposed recently and discuss the measure's usefulness.

Original languageEnglish
Pages (from-to)839-853
Number of pages15
JournalPerformance Evaluation
Issue number11-12
StatePublished - Nov 2008
Externally publishedYes


FundersFunder number
Ministry of Science and Technology, Israel380-801


    • Job scheduling
    • Predictability
    • Queue disciplines
    • Twin measure


    Dive into the research topics of 'On the twin measure and queueing systems predictability'. Together they form a unique fingerprint.

    Cite this