在前面一篇文章
用java并发测试tokyo cabinet的性能[五四陈手记]
提到了测试tc的效率问题，最后的结论是70W/s，由于当时的错误，导致了一些严重影响大家的结论，如今本着认真治学，谨慎小心的态度，重新公布最新的代码和结论，还望受影响的同志们不要发烧。。。
首先，总结上一次为什么会犯错的原因：
1. 测试代码有问题，TDB db = new TDB();不能放在线程中去new，也许是tc实现的问题，详细原因没有去研究。
2.赶着时间测，把写入的时候的结果直接给屏了。
重新公布新的测试代码：
package test;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Random;
import java.util.concurrent.atomic.AtomicLong;
import tokyocabinet.*;
public class BenchMark {
private static List<TDB> dbList = new ArrayList<TDB>();
public static class Stat {
private AtomicLong _count = new AtomicLong(0);
private static Stat _instance = new Stat();
public static Stat getInstance() {
return _instance;
}
private Stat() {
_printer = new RatePrinter(_count);
_printer.setDaemon(true);
_printer.start();
}
public void inc() {
_count.incrementAndGet();
}
private RatePrinter _printer;
private static class RatePrinter extends Thread {
private long _last;
private AtomicLong _c;
public RatePrinter(AtomicLong c) {
_c = c;
}
@Override
public void run() {
while (true) {
try {
long current = _c.get();
System.out.println("Rate: " + (current - _last) + " req/s");
_last = current;
Thread.sleep(1000L);
} catch (Throwable e) {
e.printStackTrace();
}
}
}
}
}
public static class EchoThread extends Thread {
// private TDB tdb;
public EchoThread(String ip, String port, int in, ThreadGroup group) {
super(group, "EchoThread-" + in);
// // create the object
// TDB tdb = new TDB();
//
// // open the database
// if(!tdb.open("casket"+in+".tct", TDB.OWRITER | TDB.OCREAT)){
// int ecode = tdb.ecode();
// System.err.println("open error: " + tdb.errmsg(ecode));
// }
}
@Override
public void run() {
int index = 0;
// create the object
Random r = new Random();
// open the database
// if (!tdb.open("casket" + Thread.currentThread().getId() + ".tct", TDB.OWRITER | TDB.OCREAT)) {
// int ecode = tdb.ecode();
// System.err.println("open error: " + tdb.errmsg(ecode));
// }
while (true) {
try {
TDB tdb = dbList.get(0);
String pkey = index + "asdf";
Map<String, String> cols = new HashMap<String, String>();
cols.put("name", "mikio" + index);
cols.put("age", "30");
cols.put("lang", "ja,en,c");
if (!tdb.put(pkey, cols)) {
int ecode = tdb.ecode();
System.err.println("put error: " + tdb.errmsg(ecode) + " key:" + pkey + " value:" + cols);
}
// client.insert("Table1", "name"+index, "Standard1:name",
// ("name"+index).getBytes("UTF-8"),
// System.currentTimeMillis(), true);
// client.get_column("Table1", "name0", "Standard1:name");
index++;
Stat.getInstance().inc();
} catch (Throwable e) {
e.printStackTrace();
break;
} finally {
// close the database
//if (!tdb.close()) {
//int ecode = tdb.ecode();
// System.err.println("close error: " +
// tdb.errmsg(ecode));
//}
}
}
}
}
/**
* @param args
* @throws TTransportException
*/
public static void main(String[] args) {
if (args.length != 1) {
System.out.println("Usage: Benchmark <concurrent>");
System.exit(1);
}
String ip = args[0];
String port = args[0];
Integer concurrent = Integer.valueOf(args[0]);
System.out.println("ip = " + ip + ",port = " + port + ",concurrent = " + concurrent);
ThreadGroup group = new ThreadGroup("Benchmark");
List<Thread> threads = new ArrayList<Thread>();
for (int i = 0; i < concurrent; i++) {
TDB db = new TDB();
//db.optimize();
if (!db.open("./test" + i + ".tdb", TDB.OCREAT | TDB.OWRITER)) {
int ecode = db.ecode();
System.err.println("open error: " + TDB.errmsg(ecode));
continue;
}
dbList.add(db);
}
for (int x = 0; x < concurrent; ++x) {
Thread t = new EchoThread(ip, port, x, group);
threads.add(t);
t.start();
}
}
}
对比上一次的代码，能够发现，1.new TDB的过程扔进了Thread.start之前；2.在thread中使用一个全局的变量来获取当前的对象。
启十个进程，全往第一个里写：
concurrent = 10
Rate: 25 req/s
Rate: 119617 req/s
Rate: 130620 req/s
Rate: 144202 req/s
Rate: 120458 req/s
Rate: 112809 req/s
Rate: 120800 req/s
Rate: 122290 req/s
Rate: 119526 req/s
Rate: 111189 req/s
Rate: 112483 req/s
Rate: 109138 req/s
Rate: 115648 req/s
Rate: 119419 req/s
Rate: 105558 req/s
Rate: 110230 req/s
Rate: 116507 req/s
Rate: 105367 req/s
Rate: 103781 req/s
Rate: 106618 req/s
Rate: 107698 req/s
Rate: 116768 req/s
Rate: 107244 req/s
保持在10w/s的写入速度，到达30s左右以后，数据急转直下：
Rate: 48060 req/s
Rate: 6901 req/s
Rate: 4987 req/s
Rate: 46229 req/s
Rate: 46686 req/s
Rate: 45402 req/s
Rate: 6271 req/s
Rate: 810 req/s
Rate: 33895 req/s
Rate: 46548 req/s
Rate: 47025 req/s
Rate: 6995 req/s
Rate: 860 req/s
这，就是tc的table表在写入一个ArrayList的真实速度（4核8G）。
官方发言的100W只需要0.4s，说的是写入的hash表，而且数据是纯线性的数字。
提升速度和稳定的办法，和张宴兄弟商量，b+tree类型的数据稳定一些，设置tctdbsetxmsiz也能解决燃眉之急。
