JVM in flames

Vagrant box used to prepare materials for my JVM in flames talk.

Box contains

Environment:

• Java 8
• hermes-frontend module for testing
• Kafka 0.10.2 required by Hermes
• wrk2 traffic generator

Profilers & tools:

• async-profiler
• honest-profiler
• hprof2flamegraph to generate flamegraphs from hpl and hprof files
• perf-map-agent perf for Java; not included in talk
• FlameGraph library for perf-map-agent

Setup

vagrant up

Running tests

Hermes Frontend binaries and run script are located in /opt. Everything should be run as root.

To run Hermes Frontend use /opt/run-hermes.sh. It can be also modified to change run arguments, see commented out sections for ways to enable different profilers and measurement options.

All profilers are located in /opt/profilers and are ready to use (compiled etc).

Warmup

After Hermes Frontend starts, run in separate shell:

wrk -t5 -d20s -c20 -R1000 -L -s hermes-traffic.lua http://localhost:8080/topics/jvm-in-flames.topic

Warmup round generates 1000rps for 20 seconds.

Measurements

wrk -t10 -d300s -c20 -R2500 -L -s hermes-traffic.lua http://localhost:8080/topics/jvm-in-flames.topic

Measurements round lasts for 5 minutes, generates 2500rps. Higher percentiles are very sensitive to any external activities, so best close all CPU-intensive apps like internet browser or IDE.

Results

Sample results used in talk are in ./results directory. Naming conventions:

• vanilla - no profilers
• jmx: JVisual VM profiler connected via JMX from host
• hprof-10: hprof profiler with default sampling interval (10ms)
• hprof-100: hprof profiler with sampling interval = 100ms
• async: async-profiler
• honest: honest-profiler

Directories:

• results/flamegraphs: flamegraphs in SVG format
• results/hdr: results from wrk2 traffic generator, compatible with HDR Histogram plotter
• results/gclog: GC logs