JCalculus


JCalculus is a Workload Modelling or Workload Distribution tool. JCalculus can help you determine the maximum number of VUsers that can be run on a Load Generator based on VUser memory footprint. JCalculus can also help you derive ThinkTime and Pacing using Little's Law for performance testing. Little's law is applied to relate concurrent users, server's throughput & total time consumed.

Concurrent Users = Transactions per Second * { Response Time + ( Think Time + Pacing ) }

Transactions per Hour
Transactions per Second
Avg. Response Time (Secs)
Concurrency
Think Time + Pacing (Secs)

Max. VUsers on LG = ( ( ( Total LG RAM - RAM for OS) * 0.75 ) ) - First VUser Memory ) / ( Additional VUser Memory + 1 )

Total LG RAM (GB)
RAM for OS (MB) [~ 750MB]
First VUser Memory (MB)
Additional VUser Memory (MB)
Max. VUsers on LG

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