async-profiler
jmh
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async-profiler | jmh | |
---|---|---|
10 | 26 | |
7,112 | 2,016 | |
2.8% | 5.1% | |
8.7 | 6.3 | |
11 days ago | 6 days ago | |
C++ | Java | |
Apache License 2.0 | GNU General Public License v3.0 only |
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.
async-profiler
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JVM Profiling in Action
We'll use async-profiler and flame graphs for profiling. To simplify the process, we'll run the code using JBang.
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The Return of the Frame Pointers
JIT'ed code is sadly poorly supported, but LLVM has had great hooks for noting each method that is produced and its address. So you can build a simple mixed-mode unwinder, pretty easily, but mostly in process.
I think Intel's DNN things dump their info out to some common file that perf can read instead, but because the *kernels* themselves reuse rbp throughout oneDNN, it's totally useless.
Finally, can any JVM folks explain this claim about DWARF info from the article:
> Doesn't exist for JIT'd runtimes like the Java JVM
that just sounds surprising to me. Is it off by default or literally not available? (Google searches have mostly pointed to people wanting to include the JNI/C side of a JVM stack, like https://github.com/async-profiler/async-profiler/issues/215).
- FLaNK Stack 29 Jan 2024
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Tracking Java Native Memory with JDK Flight Recorder
debugging native calls in itself is also painful. I have switched to using async-profiler (https://github.com/async-profiler/async-profiler) instead of JFR for most of my usecases.
A. it tracks native calls by default
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Show HN: Javaflame – Simple Flamegraph for your Java application
https://github.com/async-profiler/async-profiler#flame-graph...
Ok, Windows is not supported. But IntelliJ made a fork which works on Windows.
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Lettuce (Redis) + Mybatis (MySQL) take up most of the CPU in production - Is it normal? Did you observe that in your environment? Any ways to optimize it?
Hi, today I used async-profiler to check the CPU usage of my Spring Boot app (just a normal backend) in production. Surprisingly, Lettuce (Redis) + Mybatis (MySQL) take up most of the CPU time. I am not talking about wall time here, but CPU time, since I know database requests need to wait for milliseconds and thus wall time will be very long. Therefore, I wonder:
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A question about Http4s new major version
You can use async-profiler to see what is happening under the hood.
- Reducing code size in (Rust) librsvg by removing an unnecessary generic struct
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what is your favorite programming trick/tool that not many People know about?
I have used visual vm quite a bit. https://github.com/async-profiler/async-profiler is also amazing... Throw the binary on the system and fire it up. It also profiles down into native code as well if you do that kind of thing.
jmh
- Experimenting with GC-less (heap-less) Java
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Any library you would like to recommend to others as it helps you a lot? For me, mapstruct is one of them. Hopefully I would hear some other nice libraries I never try.
JMH for benchmarks
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Scala collections benchmark - revisited
I would recommend using JMH instead.
- What are some advantages to Java devs learning assembly?
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Is calling a method with reflection slower than calling a method normally? If so, by how much?
Reflection is probably very roughly between 10 and 1000 times slower. Why don't you measure it yourself using JMH?
- I benchmarked kotlin rust and go. The results will shock you , or not.
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Need help navigating the Java ecosystem (coming from C++)
Aleksey Shipilev is another such leader, whom is especially knowledgeable about the internals of the JVM. His writings are invaluable. He is (was) the lead of the Java microbenchmark framework (JMH} which is how one would write small performance experiments in Java, and learn what really makes a difference or now.
- Are Long better than Integer as keys for a Map?
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Threads vs Coroutines - ParallelMap Performance
In the last episode we implemented a parallelMap operation using streams, raw threads, a threadpool with futures, and coroutines. At first glance the raw threads was quickest, followed by futures, coroutines and then streams. In this, part 56 of an exploration of where a Test Driven Development implementation of the Gilded Rose stock control system might take us in Kotlin, we investigate the performance of the different functions further, in particular digging down into why coroutines seem to be slow and finding a way to speed them up. We also find a way to use a particular ForkJoinPool to run the streams code, making it as fast as the others (bar the raw threads). Frankly we only use very rough benchmarks here, with no statistical testing except 'it looks like'. That's OK for gross differences, but is highly suspect when deciding which of two similarly performant approaches is faster. For that check out JMH and you could watch my video from KotlinConf 2017
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Just another way to run JMH benchmark with Eclipse
A few months ago, we started to use JMH in our project to test and find performance issues. The tool provides multiple modes and profilers, and we found this useful for our purposes.
What are some alternatives?
container-jfr - Secure JDK Flight Recorder management for containerized JVMs
async-profiler - Sampling CPU and HEAP profiler for Java featuring AsyncGetCallTrace + perf_events [Moved to: https://github.com/async-profiler/async-profiler]
jfr-libraries - a list of libraries that generate JFR events
opentelemetry-java-instrumentation - OpenTelemetry auto-instrumentation and instrumentation libraries for Java
Arthas - Alibaba Java Diagnostic Tool Arthas/Alibaba Java诊断利器Arthas
OpenJ9 - Eclipse OpenJ9: A Java Virtual Machine for OpenJDK that's optimized for small footprint, fast start-up, and high throughput. Builds on Eclipse OMR (https://github.com/eclipse/omr) and combines with the Extensions for OpenJDK for OpenJ9 repo.
go - The Go programming language
junit-jfr - a JUnit 5 extension that generates JFR events
jfr-streaming - Library for streaming Java Flight Recording (JFR) files from local or remote JVMs
opentelemetry-java - OpenTelemetry Java SDK