Cache Simulator

Simulates client-side file caching policies (LRU, LFU, ARC, LIRS, MQ, 2Q, FBR, LRFU, …) over generated request streams or AFS log files, and compares their hit ratios and saved traffic in tables and charts.

Requirements

• JDK 25 or newer
• Maven 3.9 or newer

The code is Kotlin (2.4); Maven downloads the Kotlin compiler, so nothing else needs installing.

Modules

Module	Artifact	Content
cachesim-core	cache-core	simulation engine, policies, request sources, CSV/XLS export (no UI)
cachesim-gui	cache-gui	JavaFX desktop application
cachesim-cli	cache-cli	command line and interactive terminal UI

Build

mvn clean verify

This runs the tests and ktlint (mvn ktlint:format fixes most style problems), and builds two runnable jars with all dependencies:

• cachesim-gui/target/cache-gui-3.0-alpha-jar-with-dependencies.jar
• cachesim-cli/target/cache-cli-3.0-alpha-jar-with-dependencies.jar

Run the GUI

java -jar cachesim-gui/target/cache-gui-3.0-alpha-jar-with-dependencies.jar
# or, after `mvn install -DskipTests`:
mvn -pl cachesim-gui javafx:run

The GUI is JavaFX. The runnable jar contains the JavaFX native libraries for the platform it was built on (Linux, Windows or macOS); build it on the platform you want to run it on. Running from the classpath prints a harmless Unsupported JavaFX configuration warning at startup.

Run in a terminal

alias cachesim='java -jar cachesim-cli/target/cache-cli-3.0-alpha-jar-with-dependencies.jar'

cachesim                      # interactive terminal UI (same as `cachesim tui`)
cachesim list-policies        # policy names usable with --policies
cachesim run --help           # all options

# Zipf requests, a few policies and sizes, results as tables
cachesim run -n 100000 -p lru,arc,lirs,2q,lfu-ss -c 8,64,512

# replay an AFS log, all policies, save a spreadsheet
cachesim run -l afs.log -f xls -o results.xls

run prints tables to stdout (or CSV with -f csv), and the progress bar to stderr only when attached to a terminal, so its output can be piped. Ctrl+C stops a running simulation. Settings not given on the command line come from config.xml when it exists.

The GUI stores its settings in config.xml in the working directory when it exits.

Packages

All under cz.zcu.kiv.cachesimulator:

Package	Content
policy	cache replacement policies (CachePolicy subclasses) and their registry, CachePolicies
request	request sources: random generators and the AFS log reader
server	the simulated file server and its per-cache request counters
simulation	the simulation itself (runSimulation) and its statistics
config	SimulationSettings and reading/writing config.xml
report	CSV / XLS / console export
gui	JavaFX user interface (/fx/main.fxml, /fx/app.css), in cachesim-gui
cli	picocli commands and the Lanterna terminal UI (cli.tui), in cachesim-cli

Adding a policy: write a CachePolicy subclass and add a PolicyDescriptor for it in CachePolicies. Known behaviour kept from the original simulator, on purpose, is listed in FOLLOW-UPS.md.