本地主机上的http延迟野生方差

Question

运行在10芯MBP M1上。运行一个线程客户端(wrk)和一个线程服务器(java)。youtube也在系统上运行。负载平均值为2/ 10，除GC外，这可能是造成以下潜伏期变化的原因？

            "percentile": 0,
            "latency_in_microseconds": 10
        },
        {
            "percentile": 50,
            "latency_in_microseconds": 16
        },
        {
            "percentile": 99,
            "latency_in_microseconds": 51
        },
        {
            "percentile": 99.9,
            "latency_in_microseconds": 1500
        },
        {
            "percentile": 99.99,
            "latency_in_microseconds": 9598
        },
        {
            "percentile": 99.999,
            "latency_in_microseconds": 15021
        }

在使用nginx或生锈web服务器时也会发生相同的变化。在M1、Linux或Linux EC2计算机上也是如此。是什么导致了从10微秒到15毫秒的巨大变化？谢谢

Answer 1

实际上，如果我做epoll/每5ms选择一次，上限就会稍微低一些。

wrk -d2134 -t2 -c10 http://127.0.0.1:8089 -s script.lua               took  17s at  10:14:19
Running 36m test @ http://127.0.0.1:8089
  2 threads and 10 connections
^C  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency    40.98us   18.24us   3.62ms   80.67%
    Req/Sec   109.03k     3.86k  115.50k    68.43%
  24368820 requests in 1.87m, 1.72GB read
Requests/sec: 216998.38
Transfer/sec:     15.73MB

JSON Output:
{
    "requests": 24368820,
    "duration_in_microseconds": 112299548.00,
    "bytes": 1852030320,
    "requests_per_sec": 216998.38,
    "bytes_transfer_per_sec": 16491876.89,
    "latency_distribution": [
        {
            "percentile": 0,
            "latency_in_microseconds": 10
        },
        {
            "percentile": 90,
            "latency_in_microseconds": 61
        },
        {
            "percentile": 99,
            "latency_in_microseconds": 88
        },
        {
            "percentile": 99.5,
            "latency_in_microseconds": 95
        },
        {
            "percentile": 99.9,
            "latency_in_microseconds": 117
        },
        {
            "percentile": 99.95,
            "latency_in_microseconds": 128
        },
        {
            "percentile": 99.99,
            "latency_in_microseconds": 230
        },
        {
            "percentile": 99.999,
            "latency_in_microseconds": 1803
        },
    ]
}