如何给自己做的网站留后门,网站开发费计入什么会计科目,网站开发 前端 外包,网站制作怎样容易在这篇文章中#xff1a; 关于吞吐量对延迟的影响的讨论 如何使用JLBH测量TCP回送 添加探针以测试TCP往返的两半 观察增加吞吐量对延迟的影响 了解必须降低吞吐量才能在高百分位数时获得良好的延迟。 在帖子中#xff0c;我们看到了考虑协调遗漏的影响或测量延迟一次迭… 在这篇文章中 关于吞吐量对延迟的影响的讨论 如何使用JLBH测量TCP回送 添加探针以测试TCP往返的两半 观察增加吞吐量对延迟的影响 了解必须降低吞吐量才能在高百分位数时获得良好的延迟。 在帖子中我们看到了考虑协调遗漏的影响或测量延迟一次迭代的影响将对后续迭代产生影响。 直观上我们了解吞吐量会影响延迟。 很自然 如果我们提高吞吐量我们还将提高延迟。 进入一个非常拥挤的商店将影响您选择和购买商品的速度。 另一方面考虑一个很少见的商店。 可能是因为在这样的商店中店主远离茶歇直到您等待他放下自己的茶并前往柜台为您服务时您的购买才会被延迟。 。 这正是运行基准测试并改变吞吐量时的结果。 通常当您提高吞吐量时延迟会增加但在吞吐量下降到某个阈值以下时延迟也会增加。 下面的代码对通过环回的往返TCP调用进行计时。 我们添加了两个探针 client2server –完成往返前半部分所花费的时间 server2client –完成行程的下半部分所花费的时间 这些探查没有考虑到协调的遗漏只有端到端的时间才考虑到协调的遗漏。 这是基准测试的代码 package org.latency.tcp;import net.openhft.affinity.Affinity;
import net.openhft.chronicle.core.Jvm;
import net.openhft.chronicle.core.jlbh.JLBHOptions;
import net.openhft.chronicle.core.jlbh.JLBHTask;
import net.openhft.chronicle.core.jlbh.JLBH;
import net.openhft.chronicle.core.util.NanoSampler;import java.io.EOFException;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;public class TcpBenchmark implements JLBHTask {private final static int port 8007;private static final boolean BLOCKING false;private final int SERVER_CPU Integer.getInteger(server.cpu, 0);private JLBH jlbh;private ByteBuffer bb;private SocketChannel socket;private NanoSampler client2serverProbe;private NanoSampler server2clientProbe;public static void main(String[] args) {JLBHOptions jlbhOptions new JLBHOptions().warmUpIterations(50000).iterations(50000).throughput(20000).runs(5).jlbhTask(new TcpBenchmark());new JLBH(jlbhOptions).start();}Overridepublic void init(JLBH jlbh) {this.jlbh jlbh;client2serverProbe jlbh.addProbe(client2server);server2clientProbe jlbh.addProbe(server2clientProbe);try {runServer(port);Jvm.pause(200);socket SocketChannel.open(new InetSocketAddress(port));socket.socket().setTcpNoDelay(true);socket.configureBlocking(BLOCKING);} catch (IOException e) {e.printStackTrace();}bb ByteBuffer.allocateDirect(8).order(ByteOrder.nativeOrder());}private void runServer(int port) throws IOException {new Thread(() - {if (SERVER_CPU 0) {System.out.println(server cpu: SERVER_CPU);Affinity.setAffinity(SERVER_CPU);}ServerSocketChannel ssc null;SocketChannel socket null;try {ssc ServerSocketChannel.open();ssc.bind(new InetSocketAddress(port));System.out.println(listening on ssc);socket ssc.accept();socket.socket().setTcpNoDelay(true);socket.configureBlocking(BLOCKING);System.out.println(Connected socket);ByteBuffer bb ByteBuffer.allocateDirect(8).order(ByteOrder.nativeOrder());while (true) {readAll(socket, bb);bb.flip();long time System.nanoTime();client2serverProbe.sampleNanos(time - bb.getLong());bb.clear();bb.putLong(time);bb.flip();writeAll(socket, bb);}} catch (IOException e) {e.printStackTrace();} finally {System.out.println(... disconnected socket);try {if (ssc ! null)ssc.close();} catch (IOException ignored) {}try {if (socket ! null)socket.close();} catch (IOException ignored) {}}}, server).start();}private static void readAll(SocketChannel socket, ByteBuffer bb) throws IOException {bb.clear();do {if (socket.read(bb) 0)throw new EOFException();} while (bb.remaining() 0);}Overridepublic void run(long startTimeNs) {bb.position(0);bb.putLong(System.nanoTime());bb.position(0);writeAll(socket, bb);bb.position(0);try {readAll(socket, bb);server2clientProbe.sampleNanos(System.nanoTime() - bb.getLong(0));} catch (IOException e) {e.printStackTrace();}jlbh.sample(System.nanoTime() - startTimeNs);}private static void writeAll(SocketChannel socket, ByteBuffer bb) {try {while (bb.remaining() 0 socket.write(bb) 0) ;} catch (IOException e) {e.printStackTrace();}}Overridepublic void complete() {System.exit(0);}
} 以下是以20,000次迭代/秒的吞吐量运行时的结果 Warm up complete (50000 iterations took 2.296s)
-------------------------------- BENCHMARK RESULTS (RUN 1) ---------Run time: 2.5s
Correcting for co-ordinated:true
Target throughput:20000/s 1 message every 50us
End to End: (50,000) 50/90 99/99.9 99.99 - worst was 34 / 2,950 19,400 / 20,450 20,450 - 20,450
client2server (50,000) 50/90 99/99.9 99.99 - worst was 16 / 26 38 / 72 287 - 336
server2clientProbe (50,000) 50/90 99/99.9 99.99 - worst was 16 / 27 40 / 76 319 - 901
OS Jitter (26,960) 50/90 99/99.9 99.99 - worst was 9.0 / 16 44 / 1,340 10,220 - 11,800
--------------------------------------------------------------------
-------------------------------- BENCHMARK RESULTS (RUN 2) ---------
Run time: 2.5s
Correcting for co-ordinated:true
Target throughput:20000/s 1 message every 50us
End to End: (50,000) 50/90 99/99.9 99.99 - worst was 42 / 868 4,590 / 5,110 5,370 - 5,370
client2server (50,000) 50/90 99/99.9 99.99 - worst was 20 / 27 38 / 92 573 - 2,560
server2clientProbe (50,000) 50/90 99/99.9 99.99 - worst was 19 / 27 38 / 72 868 - 1,740
OS Jitter (13,314) 50/90 99/99.9 99.99 - worst was 9.0 / 16 32 / 96 303 - 672
--------------------------------------------------------------------
-------------------------------- BENCHMARK RESULTS (RUN 3) ---------
Run time: 2.5s
Correcting for co-ordinated:true
Target throughput:20000/s 1 message every 50us
End to End: (50,000) 50/90 99/99.9 99.99 - worst was 34 / 152 999 / 2,160 2,290 - 2,290
client2server (50,000) 50/90 99/99.9 99.99 - worst was 17 / 26 36 / 54 201 - 901
server2clientProbe (50,000) 50/90 99/99.9 99.99 - worst was 16 / 25 36 / 50 225 - 1,740
OS Jitter (14,306) 50/90 99/99.9 99.99 - worst was 9.0 / 15 23 / 44 160 - 184
---------------------------------------------------------------------------------------------------- SUMMARY (end to end)---------------
Percentile run1 run2 run3 % Variation var(log)
50: 33.79 41.98 33.79 13.91
90: 2949.12 868.35 151.55 75.92
99: 19398.66 4587.52 999.42 70.53
99.9: 20447.23 5111.81 2162.69 47.62 99.99: 20447.23 5373.95 2293.76 47.24
worst: 20447.23 5373.95 2293.76 47.24
--------------------------------------------------------------------
-------------------------------- SUMMARY (client2server)------------
Percentile run1 run2 run3 % Variation
50: 16.13 19.97 16.90 10.81
90: 26.11 27.14 26.11 2.55
99: 37.89 37.89 35.84 3.67
99.9: 71.68 92.16 54.27 31.76
99.99: 286.72 573.44 200.70 55.32
worst: 335.87 2555.90 901.12 55.04
--------------------------------------------------------------------
-------------------------------- SUMMARY (server2clientProbe)-------
Percentile run1 run2 run3 % Variation
50: 16.13 18.94 16.13 10.43
90: 27.14 27.14 25.09 5.16
99: 39.94 37.89 35.84 3.67
99.9: 75.78 71.68 50.18 22.22
99.99: 319.49 868.35 225.28 65.55
worst: 901.12 1736.70 1736.70 0.00
-------------------------------------------------------------------- 应该发生的是 client2server server2client〜 endToEnd 而且这少得多的是在第50个百分点发生的情况 为了演示的目的进行第二次运行 19.97 18.94〜 41.98 如果这只是您要测量的全部您可能会说通过我的机器运行20k / s消息没有问题。 但是我的笔记本电脑显然无法处理该音量如果我们再次查看第二个90百分位数的运行情况。 27.14 27.14〜 868.35 随着百分位数的增加它变得越来越糟…… 但是如果我将吞吐量更改为每秒5k条消息我会在第90个百分位数上看到这一点 32.23 29.38〜 62.46 因此我们看到如果要在高百分位数上实现低延迟则必须将吞吐量降低到正确的水平。 这就是为什么如此重要以至于我们能够使用JLBH改变吞吐量。 翻译自: https://www.javacodegeeks.com/2016/04/jlbh-examples-3-affects-throughput-latency.html
