Simulator

The simulator includes a family of eviction policies and distribution generators. This helps when investigating whether a policy is a good fit for a usage scenario.

Usage

Run the Simulator in an IDE after specifying the desired configuration. Alternatively, run at the command line using:

# Single run, displays ascii table by default
gradlew simulator:run -q

# Multiple runs, writes a combined report, and renders a chart
gradlew simulator:simulate -q \
  --maximumSize=<comma separated list; supports _ numeric literal> \
  --theme=<light, dark> \
  --title=<optional>

# In both, additional configuration may be supplied as system properties
  -Dcaffeine.simulator.files.paths.0=multi3.trace.gz
# and custom jvm arguments can be provided
  -PjvmArgs=-Xmx6g

The following trace formats are supported.

Traces	Location	Traces	Location
AdaptSize	author's simulator	Address (UCSD)	git repository
ARC	author's drive	Cache2k	git repository
Cachelib	project's homepage	CameLab	project's homepage
Corda	git repository	GL-Cache	project's homepage
Gradle	git repository	Kaggle	project's homepage
libCacheSim	author's simulator	LIRS	git repository
LRB	author's simulator	Scarab	git repository
SNIA	project's homepage	Tragen	project's homepage
Twitter	project's homepage	UMass	project's homepage
WikiBench	project's homepage

Rewriter

The rewriter utility converts traces from one format to another. This can be helpful when comparing a policy written in an alternative simulator that lacks support for a trace format.

gradlew :simulator:rewrite -q \
  --inputFormat=<trace format> \
  --inputFiles=<comma separated paths> \
  --outputFormat=<trace format> \
  --outputFile=<path>

Sample Report

Due to batching and broadcasting, the timings are only comparable when running each policy independently.

╔══════════════════════╤══════════╤════════════╤════════════╤════════════╤════════════╤═══════════╗
║ Policy               │ Hit Rate │ Hits       │ Misses     │ Requests   │ Evictions  │ Time      ║
╠══════════════════════╪══════════╪════════════╪════════════╪════════════╪════════════╪═══════════╣
║ opt.Clairvoyant      │ 48.09 %  │ 21,019,597 │ 22,685,382 │ 43,704,979 │ 18,685,382 │ 2.301 min ║
╟──────────────────────┼──────────┼────────────┼────────────┼────────────┼────────────┼───────────╢
║ sketch.WindowTinyLfu │ 45.25 %  │ 19,775,085 │ 23,929,894 │ 43,704,979 │ 19,929,894 │ 1.460 min ║
╟──────────────────────┼──────────┼────────────┼────────────┼────────────┼────────────┼───────────╢
║ irr.Lirs             │ 38.14 %  │ 16,668,577 │ 27,036,402 │ 43,704,979 │ 23,036,402 │ 1.319 min ║
╟──────────────────────┼──────────┼────────────┼────────────┼────────────┼────────────┼───────────╢
║ adaptive.Arc         │ 29.60 %  │ 12,938,241 │ 30,766,738 │ 43,704,979 │ 26,766,738 │ 1.249 min ║
╟──────────────────────┼──────────┼────────────┼────────────┼────────────┼────────────┼───────────╢
║ linked.Lru           │ 20.24 %  │  8,847,982 │ 34,856,997 │ 43,704,979 │ 30,856,997 │ 1.218 min ║
╚══════════════════════╧══════════╧════════════╧════════════╧════════════╧════════════╧═══════════╝