memcache安裝、配置、測試

       今天拿到一台幹淨的linux虛拟器，安裝memcache，首先安裝libevent庫。

wget https://github.com/downloads/libevent/libevent/libevent-1.4.14b-stable.tar.gz
tar xvzf libevent-1.4.14b-stable.tar.gz
./configure
make
make install
           

 然後，編譯、安裝、配置Memcached，執行如下指令行：

wget http://www.memcached.org/files/memcached-1.4.20.tar.gz
tar xvzf memcached-1.4.20.tar.gz
ln -s /usr/local/memcached-1.4.20 /usr/local/memcached
./configure --with-libevent=/usr/local/libevent/
make
make install
           

安裝過程中遇見這個問題：/usr/local/memcached/bin/memcached: error while loading shared libraries: libevent-1.4.so.2: cannot open shared object file: No such file or directory

解決類似問題的步驟：

1. 首先 find / -name libevent-1.4.so.2 找到缺少的連結檔案到底在那兒。

2. LD_DEBUG=libs /usr/local/bin/memcached -v

3. 從Debug資訊中就知道程式去哪裡找連結庫了。我這邊程式去 trying file=/usr/lib/libevent-1.4.so.2 而我的連結庫的實際存儲位置是 /usr/local/lib/libevent-1.4.so.2

4. 做一個軟連接配接 ln -s /usr/local/lib/libevent-1.4.so.2 /usr/lib/libevent-1.4.so.2

5. 搞定。

最後啟動memcache ：

/usr/local/bin/memcached -d -m 2014 -I 20m -u root  -p 12800 -c 1024 -t20
           

寫個小程式驗證一下memecahe是否可以正常使用，輸出都内容正确就OK

package com.testpai;

import net.spy.memcached.AddrUtil;
import net.spy.memcached.BinaryConnectionFactory;
import net.spy.memcached.MemcachedClient;
import net.spy.memcached.internal.OperationFuture;

public class TestMemcached {
	public static void main(String[] args) throws Exception {
        String address = "10.6.2.95:12800";
        MemcachedClient client = new MemcachedClient(new BinaryConnectionFactory(),
                  AddrUtil.getAddresses(address));

        String key = "magic_words";
        int exp = 3600;
        String o = "hello";
        // set
        OperationFuture<Boolean> setFuture = client.set(key, exp, o);
        if(setFuture.get()) {
             // get
             System.out.println(client.get(key));

             // append
             client.replace(key, exp, " the world!");
             System.out.println(client.get(key));


             // prepend
             client.prepend(exp, key, "Stone, ");
             System.out.println(client.get(key));

             // replace
             o = "This is a test for spymemcached.";
             OperationFuture<Boolean> replaceFuture = client.replace(key, exp, o);
             if(replaceFuture.get()) {
                  System.out.println(client.get(key));

                  // delete
                  client.delete(key);
                  System.out.println(client.get(key));
             }
        }

        client.shutdown();
   }
}