Epoch-based Commit Simulations

There are 3 simulation programs:

1. sim-infinite-queue-epoch:
   • Nodes are never idle
   • Failures are detected at epoch-level granularity
   • Lost jobs have same service time as completed jobs
2. sim-finite-queue-epoch:
   • There is an external queue, nodes can be idle
   • Failures are detected at epoch-level granularity
   • Lost jobs have same service time as completed jobs and are retried infinitely
3. sim-commit-groups: simulate non-failing epochs running TPC-C workload. Used to determine the number of commit groups.

Parameters

Default parameters, the unit is ms unless specified otherwise:

• Cluster size: n=50
• Epoch timeout: a=100
• Commit operation service rate: b=10
• Abort operation service rate: c=10
• Transaction service rate: mu=1
• Mean time between failures: phi=20000
• Repair rate: rho=1000
• Fixed seed: s=false
• Time limit: d=3600 (seconds)
• Protocol: p=single; options are multi and single
• Proportion of distributed transaction: m=1
• Affinity: af=false

sim-finite-queue-epoch only:

• Set seed value: sv=0
• Arrival rate: ar=0.0208

Results are saved to simulation/results.csv, the following statistics are reported:

• Completed jobs per ms
• Lost jobs per ms
• Average number of commit groups (multi-commit only)
• Average response time (sim-finite-queue-epoch only)

Run

Each simulation program is dockerised and is run for each protocol across a range of a values.

# build docker image with latest jar
cd <sim>
./build-image.sh

# run docker containers
cd scripts
./coordinator.sh <time>

# extract results
./get-files.sh

# generate plots 
./make-plots.sh