I'm using JMH to benchmark JUnit tests. I want to start using async-profiler, to profile the benchmarks and get more information regarding CPU usage.
My benchmark runner:
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.profile.AsyncProfiler;
import org.openjdk.jmh.results.format.ResultFormatType;
import org.openjdk.jmh.runner.options.Options;
import org.openjdk.jmh.runner.options.OptionsBuilder;
import org.openjdk.jmh.runner.Runner;
import org.openjdk.jmh.runner.options.TimeValue;
import java.util.concurrent.TimeUnit;
public class BenchmarkRunner {
public static void main(String[] args) throws Exception {
Options opt = new OptionsBuilder()
.include(Benchmarks.class.getSimpleName())
.addProfiler(AsyncProfiler.class, "output=flamegraph")
.mode(Mode.Throughput)
.resultFormat(ResultFormatType.CSV)
.result("target/test-classes/benchmarkcsv/BM " System.currentTimeMillis() ".csv")
.timeUnit(TimeUnit.MILLISECONDS)
.warmupIterations(3)
.warmupTime(TimeValue.seconds(1))
.measurementIterations(3)
.measurementTime(TimeValue.seconds(1))
.timeout(TimeValue.seconds(5))
.forks(1)
.warmupForks(1)
.threads(1)
.build();
new Runner(opt).run();
}
}
While running this, I'm getting the following error:
Exception in thread "main" org.openjdk.jmh.runner.ProfilersFailedException: Profilers failed to initialize, exiting.
at org.openjdk.jmh.runner.Runner.internalRun(Runner.java:228)
at org.openjdk.jmh.runner.Runner.run(Runner.java:209)
at DummyApp.BenchmarkRunner.main(BenchmarkRunner.java:33)
Caused by: org.openjdk.jmh.profile.ProfilerException: Unable to load async-profiler. Ensure asyncProfiler library is on LD_LIBRARY_PATH (Linux), DYLD_LIBRARY_PATH (Mac OS), or -Djava.library.path. Alternatively, point to explicit library location with -prof async:libPath=<path>.
at org.openjdk.jmh.profile.AsyncProfiler.<init>(AsyncProfiler.java:237)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.openjdk.jmh.profile.ProfilerFactory.instantiate(ProfilerFactory.java:82)
at org.openjdk.jmh.profile.ProfilerFactory.getProfiler(ProfilerFactory.java:77)
at org.openjdk.jmh.profile.ProfilerFactory.getProfilerOrException(ProfilerFactory.java:37)
at org.openjdk.jmh.runner.Runner.internalRun(Runner.java:225)
... 2 more
Caused by: java.lang.UnsatisfiedLinkError: no asyncProfiler in java.library.path
at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1867)
at java.lang.Runtime.loadLibrary0(Runtime.java:870)
at java.lang.System.loadLibrary(System.java:1122)
at org.openjdk.jmh.profile.AsyncProfiler$JavaApi.<init>(AsyncProfiler.java:584)
at org.openjdk.jmh.profile.AsyncProfiler$JavaApi.getInstance(AsyncProfiler.java:573)
at org.openjdk.jmh.profile.AsyncProfiler.<init>(AsyncProfiler.java:234)
... 10 more
Process finished with exit code 1
According to the async-profiler Github page, async-profiler comes bundled with IntelliJ IDEA Ultimate 2018.3 and later. I'm running the IntelliJ IDEA Community Edition 2021.3.2 on my system, but I'm unable to find the library.
How can I find this library/solve this error I'm getting?
CodePudding user response:
The exception message tells exactly what happens and how to solve it:
Unable to load async-profiler. Ensure asyncProfiler library is on
LD_LIBRARY_PATH (Linux), DYLD_LIBRARY_PATH (Mac OS), or -Djava.library.path.
Alternatively, point to explicit library location with -prof async:libPath=<path>.
Get async-profiler from
https://github.com/jvm-profiling-tools/async-profiler/releases, and set the path to libasyncProfiler.so
in LD_LIBRARY_PATH
environment variable or in -Djava.library.path
JVM option.
On Windows you can choose another JMH profiler: -prof jfr
or addProfiler(JavaFlightRecorderProfiler.class)
. This will produce .jfr
recording that you can open directly in JDK Mission Control or convert to a Flame Graph using converter.jar from async-profiler.