CentOS 安装 Memcache 服务器. java 做客户端.

 

1,下载安装第三方源:

 

CentOS 6 或 RedHat 6 安装此rpm , 其他 下载 :http://pkgs.repoforge.org/rpmforge-release/

 

 

wget http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.i686.rpm

rpm -ivh rpmforge-release-0.5.2-2.el6.rf.i686.rpm

 

wget http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.x86_64.rpm

rpm -ivh rpmforge-release-0.5.2-2.el6.rf.x86_64.rpm

 

2,安装memcahce.

yum install memcached

 

 

3,启动服务.

 

service memcached start

 

将服务设置 为自动启动：

 

chkconfig memcached on

 

 

4,测试客户端.(需要安装 nc)

 

yum install nc

 

具体命令参考:[引用]

 

http://blog.s135.com/post/384/

 

 

1、数据存储（假设key为zhangyan，value为12345）

printf "set zhangyan 0 0 5\r\n12345\r\n" | nc 127.0.0.1 11211

　STORED

　　2、数据取回（假设key为zhangyan）

printf "get zhangyan\r\n" | nc 127.0.0.1 11211

　VALUE zhangyan 0 5
　12345
　END

　　3、数值增加1（假设key为zhangyan，并且value为正整数）

printf "incr zhangyan 1\r\n" | nc 127.0.0.1 11211

　12346

　　4、数值减少3（假设key为zhangyan，并且value为正整数）

printf "decr zhangyan 3\r\n" | nc 127.0.0.1 11211

　12343

　　5、数据删除（假设key为zhangyan）

printf "delete zhangyan\r\n" | nc 127.0.0.1 11211

　DELETED

　　6、查看Memcached状态

printf "stats\r\n" | nc 127.0.0.1 11211

　STAT pid 3025
　STAT uptime 4120500
　STAT time 1228021767
　STAT version 1.2.6
　STAT pointer_size 32
　STAT rusage_user 433.463103
　STAT rusage_system 1224.515845
　STAT curr_items 1132460
　STAT total_items 8980260
　STAT bytes 1895325386
　STAT curr_connections 252
　STAT total_connections 547850
　STAT connection_structures 1189
　STAT cmd_get 13619685
　STAT cmd_set 8980260
　STAT get_hits 6851607
　STAT get_misses 6768078
　STAT evictions 0
　STAT bytes_read 160396238246
　STAT bytes_written 260080686529
　STAT limit_maxbytes 2147483648
　STAT threads 1
　END

　　7、模拟top命令，查看Memcached状态：

watch "printf 'stats\r\n' | nc 127.0.0.1 11211"

　　或者

watch "echo stats | nc 127.0.0.1 11211"

 

 

5.使用java 客户端连接memcache服务器.

 

继续添加虚拟机端口.

 

同时修改 iptables 配置文件.

 

重启 iptables

 

 

service iptables restart

 

5,java 工程 demo.

 

 

package com.test.demo;

import java.io.IOException;
import java.net.InetSocketAddress;
import net.spy.memcached.MemcachedClient;

public class MemcachedDemo {

	public static void main(String[] args) throws IOException {

		long t1 = System.currentTimeMillis();

		MemcachedClient memcachedClient = new MemcachedClient(
				new InetSocketAddress("127.0.0.1", 11211));
		// 可以设置多个..new InetSocketAddress("127.0.0.1", 11211)

		for (int i = 0; i < 10000; i++) {
			UserInfo userInfo = new UserInfo();
			userInfo.setUserName("name" + i);
			userInfo.setPasswd("passwd" + i);
			userInfo.setAge(i % 99);
			// 更新后被替换..
			memcachedClient.add("user_" + i, 3600, userInfo);
		}
		System.out.println("finish.");

		// 删除key
		memcachedClient.delete("user_0");
		memcachedClient.delete("user_1");
		memcachedClient.delete("user_2");

		// 按照key得到数据.
		for (int i = 0; i < 10000; i++) {
			if (i % 1000 == 0) {
				Object userInfo = memcachedClient.get("user_" + i);
				System.out.println(i + "\t" + userInfo);
			}
		}

		for (int i = 3; i < 1000; i++) {
			// 删除数据
			memcachedClient.delete("user_" + i);
		}

		// 一定用完毕要关闭.
		memcachedClient.shutdown();

		long t2 = System.currentTimeMillis();
		System.out.println("Program has executed for "
				+ (int) ((t2 - t1) / 1000) + " s " + ((t2 - t1) % 1000)
				+ " ms ");
	}

}

 

 

执行结果:

 

 

 

 

 

有的时候会报错误.是因为一次取数据太多了.超时了.

 

 

Exception in thread "main" net.spy.memcached.OperationTimeoutException: Timeout waiting for value
	at net.spy.memcached.MemcachedClient.get(MemcachedClient.java:1142)
	at net.spy.memcached.MemcachedClient.get(MemcachedClient.java:1157)
	at com.test.demo.MemcachedDemo.main(MemcachedDemo.java:35)
Caused by: net.spy.memcached.internal.CheckedOperationTimeoutException: Timed out waiting for operation - failing node: /127.0.0.1:11211
	at net.spy.memcached.internal.OperationFuture.get(OperationFuture.java:65)
	at net.spy.memcached.internal.GetFuture.get(GetFuture.java:37)
	at net.spy.memcached.MemcachedClient.get(MemcachedClient.java:1135)
	... 2 more

 

 是在测试的时候 循环了 10000 次造成的吧..

 

也可.在 hibernate 里面配置 二级缓存 为 memcache .

 

附件:

java 工程下载.

 

下载java_src