LoadTester.java

package com.livefyre.livecount;

import static com.livefyre.livecount.Util.p;
import static com.livefyre.livecount.Util.randomHost;
import static com.livefyre.livecount.Util.randomId;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

public class LoadTester implements Runnable {
    public static MetricAggregator metrics = new MetricAggregator();

    private int nThreads = 600;
    private int nRequests = 6000;
    private List<String> hosts;
    private int delay = 5;

    public static Builder newbuilder() {
        return new Builder();
    }

    private LoadTester() {
        hosts = new ArrayList<String>();
        hosts.add("http://genes-macbook-pro.local:8905");
        // hosts.add("http://genes-macbook-pro.local:8906");
        // hosts.add("http://genes-macbook-pro.local:8907");
    }

    public void run() {
        p("Thread %s starting %d clients", Thread.currentThread().getName(),
                (int) Math.floor(nRequests / nThreads));
        Client[] clients = new Client[(int) Math.floor(nRequests / nThreads)];

        for (int i = 0; i < clients.length; i++) {
            clients[i] = new Client(randomHost(hosts), randomId(10000000), randomId(1000000000));
        }
        int i = 0;
        while (true) {
            clients[i].run();
            i++;
            if (i >= clients.length) {
                i = 0;
            }

            try {
                Thread.sleep(delay);
            } catch (InterruptedException e) {
            }
        }

    }

    public void start() throws InterruptedException {
        p("Starting Load Tester { threads: %d, requests: %d }", nThreads,
                (int) Math.floor(nRequests / nThreads) * nThreads);

        for (int i = 0; i < nThreads; i++) {
            new Thread(this).start();
        }
        Executors.newScheduledThreadPool(1).scheduleAtFixedRate(new Runnable() {
            public void run() {
                p(metrics);
            }
        }, 0, 10, TimeUnit.SECONDS);
    }

    static class Builder {
        private boolean isBuilt = false;
        private LoadTester loadTester;

        public Builder() {
            loadTester = new LoadTester();
        }

        private void checkBuilt() {
            if (isBuilt) {
                throw new IllegalStateException("The object cannot be modified after built");
            }
        }

        public Builder setThreads(int val) {
            checkBuilt();
            loadTester.nThreads = val;
            return this;
        }

        public Builder setHosts(List<String> val) {
            checkBuilt();
            loadTester.hosts = val;
            return this;
        }

        public Builder setRequests(int val) {
            checkBuilt();
            loadTester.nRequests = val;
            return this;
        }

        public LoadTester build() {
            checkBuilt();
            isBuilt = true;
            return loadTester;
        }
    }
}