Hi, Good job! There is a similar pr here (using the netty version, copy code): https://github.com/apache/incubator-dubbo/pull/2439
I saw that you submitted a test example about performance. I think it is more recommended to use the jdk version if the gap is not large, so I closed the duplicate one. If there are other considerations, re-open this duplicate one. Best regards! 徐靖峰 <[email protected]> 于2018年9月5日周三 下午12:17写道： > Hi community, > i changed the random implementation for dubbo, you can see as below. > > Details > > This issue links to this pull request ( > https://github.com/apache/incubator-dubbo/pull/2433) > > A little change, replace Random with ThreadLocalRandom in > LeastActiveLoadBalance and RandomLoadBalance. > > Use of ThreadLocalRandom rather than shared Random objects in concurrent > programs will typically encounter much less overhead and contention. > > Use of ThreadLocalRandom is particularly appropriate when multiple tasks . > > Benchmark > > There are some attentions need to be noticed before benchmark. > > third-party dependency need use carefully. > > bugs fix need to trace from upstream repository. > > performance benchmark > > I have compared the three cases : Random,ThreadLocalRandom from JDK, > ThreadLocalRandom from netty. > @BenchmarkMode({Mode.AverageTime}) @OutputTimeUnit(TimeUnit.NANOSECONDS) > @Warmup(iterations = 3, time = 5) @Measurement(iterations = 3, time = 5) > @Threads(50) @Fork(1) @State(Scope.Benchmark) public class RandomBenchmark > { Random random = new Random(); @Benchmark public int random() > { return random.nextInt(); } @Benchmark public int > threadLocalRandom() { return > ThreadLocalRandom.current().nextInt(); } @Benchmark public int > nettyThreadLocalRandom() { return > io.netty.util.internal.ThreadLocalRandom.current().nextInt(); } > public static void main(String[] args) throws RunnerException { > Options opt = new OptionsBuilder() > .include(RandomBenchmark.class.getSimpleName()) .build(); > new Runner(opt).run(); } } > and below is our benchmark result under 50 concurrency > Benchmark Mode Cnt Score Error > Units RandomBenchmark.nettyThreadLocalRandom avgt 3 160.321 ± > 83.518 ns/op RandomBenchmark.random avgt 3 3281.972 > ± 2093.187 ns/op RandomBenchmark.threadLocalRandom avgt 3 > 91.505 ± 39.702 ns/op > From the result we can know the truth > > Both the performance (according to above benchmark) and the stability（it > is from the JDK） > JDK 's ThreadLocalRandom looks good.
