clj-async-profiler

You can read the motivation behind clj-async-profiler and the usage example in the blog post.

This library is a thin Clojure wrapper around the excellent async-profiler and FlameGraph.

async-profiler is a low overhead sampling profiler for JVM that does not suffer from the safepoint bias problem. It operates by attaching a native Java agent to a running JVM process and collecting the stack traces samples by using HotSpot-specific APIs.

FlameGraph is a set of scripts to generate flame graphs. Flame graphs are a visualization of profiled software, allowing the most frequent code-paths to be identified quickly and accurately.

Usage

clj-async-profiler is only supported on GNU/Linux and MacOS. See https://github.com/jvm-profiling-tools/async-profiler#supported-platforms.

Add to your dependencies:

[com.clojure-goes-fast/clj-async-profiler "0.1.0"]

Note: if you are using GNU/Linux and see stackframes like /usr/lib/.../libjvm.so, it means that you have to install JDK debug symbols. E.g., on Ubuntu that would be the package openjdk-8-dbg.

clj-async-profiler exposes an all-in-one facade for generating profiling flame graphs. The most common usage scenario looks like this:

(require '[clj-async-profiler.core :as prof])

;; something CPU-heavy is already running

(prof/profile-for 10 {}) ; Run profiler for 10 seconds

;; The resulting flamegraph will be stored in /tmp/clj-async-profiler/results/
;; You can view the SVG directly from there or start a local webserver:

(prof/serve-files 8080) ; Serve on port 8080

You can also start and stop the profiler manually with prof/start and prof/stop.

Each profiling command accepts a map of options. See docstrings for each command for the list of supported options.

Each profiling command optionnally accepts a PID as a first argument. If PID is provided, an external JVM process will be sampled, otherwise the current process is targeted.

License

async-profiler is distributed under Apache-2.0. See APACHE_PUBLIC_LICENSE file. The location of the original repository is https://github.com/jvm-profiling-tools/async-profiler.

Copyright 2017 Andrei Pangin

flamegraph.pl is distributed under CDDL-1.0. See COMMON_DEVELOPMENT_AND_DISTRIBUTION_LICENSE file. The original file location is https://github.com/brendangregg/FlameGraph/blob/master/flamegraph.pl.

Copyright 2016 Netflix, Inc.
Copyright 2011 Joyent, Inc. All rights reserved.
Copyright 2011 Brendan Gregg. All rights reserved.

lein-simpleton is distributed under the Eclipse Public License. See ECLIPSE_PUBLIC_LICENSE.

Copyright 2013 Fogus and contributors.

clj-async-profiler is distributed under the Eclipse Public License. See ECLIPSE_PUBLIC_LICENSE.

Copyright 2017 Alexander Yakushev