memcached 命令： http://donald-draper.iteye.com/blog/2395628
Memcached客户端： http://donald-draper.iteye.com/blog/2396260
Memcached分布式客户端（Xmemcached）： http://donald-draper.iteye.com/blog/2396313
从1.3版本开始，xmemcached支持failure模式。所谓failure模式是指，当一个memcached节点down掉的时候，
发往这个节点的请求将直接失败，而不是发送给下一个有效的memcached节点。具体可以看memcached的文档。
默认不启用failure模式，启用failure模式可以通过下列代码：
MemcachedClientBuilder builder=…… builder.setFailureMode(true);
不仅如此，xmemcached还支持主辅模式，你可以设置一个memcached的节点的备份节点，当主节点down掉的情况下，
会将本来应该发往主节点的请求转发给standby备份节点。使用备份节点的前提是启用failure模式。备份节点设置如下：
MemcachedClient builder=new XmemcachedClientBuilder(AddrUtil.
getAddressMap("localhost:11211,localhost:11212 host2:11211,host2:11212"));
上面的例子，将localhost:11211的备份节点设置为localhost:11212,而将host2:11211的备份节点设置为host2:11212
本文的源代码可以从以下地址load:
https://github.com/Donaldhan/memcached-demo
启动4个memcached实例：
[memcached@donald ~]$ memcached -p 11211 -d -u memcached -l 192.168.126.128 -c 1024 [memcached@donald ~]$ memcached -p 11212 -d -u memcached -l 192.168.126.128 -c 1024 [memcached@donald ~]$ memcached -p 11213 -d -u memcached -l 192.168.126.128 -c 1024 [memcached@donald ~]$ memcached -p 11214 -d -u memcached -l 192.168.126.128 -c 1024 [memcached@donald ~]$ ps -ef | grep memcached root 4159 1243 0 08:53 ? 00:00:00 sshd: memcached [priv] memcach+ 4161 4159 0 08:53 ? 00:00:00 sshd: memcached@pts/1 memcach+ 4288 1 0 08:54 ? 00:00:00 memcached -p 11211 -d -u memcached -l 192.168.126.128 -c 1024 memcach+ 4299 1 0 08:54 ? 00:00:00 memcached -p 11212 -d -u memcached -l 192.168.126.128 -c 1024 memcach+ 4310 1 0 08:54 ? 00:00:00 memcached -p 11213 -d -u memcached -l 192.168.126.128 -c 1024 memcach+ 4329 1 0 08:55 ? 00:00:00 memcached -p 11214 -d -u memcached -l 192.168.126.128 -c 1024 memcach+ 4340 4163 0 08:55 pts/1 00:00:00 grep --color=auto memcached [memcached@donald ~]$
规划主备节点如下：
11211主节点的备节点为11213，主节点11212的备节点为11214。
创建memcache属性文件memcached.properties：
############################ ##memcached server ip address list ############standby############## standbyServerList=192.168.126.128:11211 ############Distribute############## distributeServerList=192.168.126.128:11211 192.168.126.128:11212 192.168.126.128:11213 ############Failure############## failureServerList=192.168.126.128:11211,192.168.126.128:11213 192.168.126.128:11212,192.168.126.128:11214 poolName=sidsock poolSize=16
创建属性文件工具类：
package util;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
*
* @author donald
* 2017年9月29日
* 下午10:21:34
*/
public class PropertiesUtil {
private static final Logger log = LoggerFactory.getLogger(PropertiesUtil.class);
private static final String MEMCACHED_CONFIG_FILE = "memcached.properties";
private static volatile PropertiesUtil instance = null;
private static Properties properties = null;
static{
if (properties == null) {
properties = new Properties();
}
try {
InputStream inputStream = Thread.currentThread().getContextClassLoader()
.getResourceAsStream(MEMCACHED_CONFIG_FILE);
properties.load(inputStream);
} catch (IOException e1) {
e1.printStackTrace();
}
}
/**
*
* @return
*/
public static synchronized PropertiesUtil getInstance() {
if (instance == null) {
instance = new PropertiesUtil();
}
return instance;
}
/**
*
* @param key
* @return
*/
public String getProperty(String key) {
return properties.getProperty(key);
}
/**
* 获取属性int值
* @param key
* @return
*/
public Integer getInteger(String key) {
String value = properties.getProperty(key);
return Integer.valueOf(value);
}
public static void main(String[] args) {
log.info("serverList:"+PropertiesUtil.getInstance().getProperty("failureServerList"));
}
}
创建memcache failure模式客户端：
package bootstrap.client;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.util.List;
import java.util.Map;
import java.util.concurrent.TimeoutException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import net.rubyeye.xmemcached.Counter;
import net.rubyeye.xmemcached.GetsResponse;
import net.rubyeye.xmemcached.MemcachedClient;
import net.rubyeye.xmemcached.MemcachedClientBuilder;
import net.rubyeye.xmemcached.XMemcachedClientBuilder;
import net.rubyeye.xmemcached.exception.MemcachedException;
import net.rubyeye.xmemcached.utils.AddrUtil;
import util.PropertiesUtil;
/**
* Memcached Failure 模式客户端
* @author donald
* 2017年10月10日
* 下午12:49:45
*/
public class MemcachedFailureClient {
private static final Logger log = LoggerFactory.getLogger(MemcachedFailureClient.class);
private static final String MEMCACHED_SERVER_LIST = "failureServerList";
private static PropertiesUtil propertiesUtil = PropertiesUtil.getInstance();
private static volatile MemcachedFailureClient instance;
private static MemcachedClientBuilder builder;
private static MemcachedClient memcachedClient;
static{
String failureServerList = propertiesUtil.getProperty(MEMCACHED_SERVER_LIST);
Map serverAddressesMap = AddrUtil.getAddressMap(failureServerList);
builder = new XMemcachedClientBuilder(serverAddressesMap);
builder.setFailureMode(true);
try {
memcachedClient = builder.build();
} catch (IOException e) {
log.error("连接异常");
e.printStackTrace();
}
}
public static synchronized MemcachedFailureClient getInstance() {
if (instance == null) {
instance = new MemcachedFailureClient();
}
return instance;
}
/**
*
* @param key
* @param value
* @return
*/
public boolean set(String key,Object value){
return set(key, 0, value);
}
/**
*
* @param key
* @param expire 过期时间秒
* @param value
* @return
*/
public boolean set(String key,int expire,Object value){
boolean finish = false;
try {
finish = memcachedClient.set(key, expire, value);
} catch (TimeoutException e) {
log.error("set超时");
e.printStackTrace();
} catch (InterruptedException e) {
log.error("set中断异常");
e.printStackTrace();
} catch (MemcachedException e) {
log.error("set错误");
e.printStackTrace();
}
return finish;
}
/**
*
* @param key
* @param value
* @return
*/
public boolean add(String key,Object value){
return add(key, 0, value);
}
/**
*
* @param key
* @param expire 过期时间秒
* @param value
* @return
*/
public boolean add(String key,int expire,Object value){
boolean finish = false;
try {
finish = memcachedClient.add(key, expire, value);
} catch (TimeoutException e) {
log.error("add超时");
e.printStackTrace();
} catch (InterruptedException e) {
log.error("add中断异常");
e.printStackTrace();
} catch (MemcachedException e) {
log.error("add错误");
e.printStackTrace();
}
return finish;
}
/**
*
* @param key
* @return
*/
public Object get(String key){
Object value = null;
try {
value = memcachedClient.get(key);
} catch (TimeoutException e) {
log.error("get超时");
e.printStackTrace();
} catch (InterruptedException e) {
log.error("get中断异常");
e.printStackTrace();
} catch (MemcachedException e) {
log.error("get操作错误");
e.printStackTrace();
}
return value;
}
/**
*
* @param key
* @param appendValue
* @return
*/
public boolean append(String key,Object appendValue){
boolean finish = false;
try {
finish = memcachedClient.append(key, appendValue);
} catch (TimeoutException e) {
log.error("append超时");
e.printStackTrace();
} catch (InterruptedException e) {
log.error("append中断异常");
e.printStackTrace();
} catch (MemcachedException e) {
log.error("append操作错误");
e.printStackTrace();
}
return finish;
}
/**
*
* @param key
* @param prependValue
* @return
*/
public boolean prepend(String key,Object prependValue){
boolean finish = false;
try {
finish = memcachedClient.prepend(key, prependValue);
} catch (TimeoutException e) {
log.error("prepend超时");
e.printStackTrace();
} catch (InterruptedException e) {
log.error("prepend中断异常");
e.printStackTrace();
} catch (MemcachedException e) {
log.error("prepend操作错误");
e.printStackTrace();
}
return finish;
}
/**
*
* @param key
* @param value
* @return
*/
public boolean replace(String key,Object value){
return replace(key, 0, value);
}
/**
*
* @param key
* @param expire 过期时间秒
* @param value
* @return
*/
public boolean replace(String key,int expire,Object value){
boolean finish = false;
try {
finish = memcachedClient.replace(key, expire, value);
} catch (TimeoutException e) {
log.error("replace超时");
e.printStackTrace();
} catch (InterruptedException e) {
log.error("replace中断异常");
e.printStackTrace();
} catch (MemcachedException e) {
log.error("replace错误");
e.printStackTrace();
}
return finish;
}
/**
*
* @param key
* @param expire
* @return
*/
public boolean touch(String key,int expire){
boolean finish = false;
try {
finish = memcachedClient.touch(key, expire);
} catch (TimeoutException e) {
log.error("touch超时");
e.printStackTrace();
} catch (InterruptedException e) {
log.error("touch中断异常");
e.printStackTrace();
} catch (MemcachedException e) {
log.error("touch操作错误");
e.printStackTrace();
}
return finish;
}
/**
* @param key
* @param step
* @param defalut
* @return
*/
public long incr(String key,long step,long defalut){
long value = 0;
try {
value = memcachedClient.incr(key, step, defalut);
} catch (TimeoutException e) {
log.error("incr超时");
e.printStackTrace();
} catch (InterruptedException e) {
log.error("incr中断异常");
e.printStackTrace();
} catch (MemcachedException e) {
log.error("incr操作错误");
e.printStackTrace();
}
return value;
}
/**
*
* @param key
* @param step
* @return
*/
public long incr(String key,long step){
long value = 0;
try {
value = memcachedClient.incr(key, step);
} catch (TimeoutException e) {
log.error("incr超时");
e.printStackTrace();
} catch (InterruptedException e) {
log.error("incr中断异常");
e.printStackTrace();
} catch (MemcachedException e) {
log.error("incr操作错误");
e.printStackTrace();
}
return value;
}
/**
*
* @param key
* @param step
* @return
*/
public long decr(String key,long step){
long value = 0;
try {
value = memcachedClient.decr(key, step);
} catch (TimeoutException e) {
log.error("decr超时");
e.printStackTrace();
} catch (InterruptedException e) {
log.error("decr中断异常");
e.printStackTrace();
} catch (MemcachedException e) {
log.error("decr操作错误");
e.printStackTrace();
}
return value;
}
/**
*
* @param key
* @return
*/
public long gets(String key){
long sid = 0;
try {
GetsResponse result = memcachedClient.gets(key);
sid = result.getCas();
} catch (TimeoutException e) {
log.error("gets超时");
e.printStackTrace();
} catch (InterruptedException e) {
log.error("gets中断异常");
e.printStackTrace();
} catch (MemcachedException e) {
log.error("gets操作错误");
e.printStackTrace();
}
return sid;
}
/**
*
* @param key
* @param obj
* @return
*/
public boolean cas(String key,Object obj){
boolean finish = false;
long sid = gets(key);
finish = cas(key, 0, obj, sid);
return finish;
}
/**
*
* @param key
* @param expire
* @param obj
* @param sid key当前版本id
* @return
*/
public boolean cas(String key, int expire, Object obj, long sid){
boolean finish = false;
try {
finish = memcachedClient.cas(key, expire, obj, sid);
} catch (TimeoutException e) {
log.error("cas超时");
e.printStackTrace();
} catch (InterruptedException e) {
log.error("cas中断异常");
e.printStackTrace();
} catch (MemcachedException e) {
log.error("cas操作错误");
e.printStackTrace();
}
return finish;
}
/**
* @param key
* @return
*/
public boolean delete(String key){
boolean finish = false;
try {
finish = memcachedClient.delete(key);
} catch (TimeoutException e) {
log.error("delete超时");
e.printStackTrace();
} catch (InterruptedException e) {
log.error("delete中断异常");
e.printStackTrace();
} catch (MemcachedException e) {
log.error("delete操作错误");
e.printStackTrace();
}
return finish;
}
/**
*
* @param key
* @return
*/
public void deleteWithNoReply(String key){
try {
memcachedClient.deleteWithNoReply(key);
} catch (InterruptedException e) {
log.error("deleteWithNoReply中断异常");
e.printStackTrace();
} catch (MemcachedException e) {
log.error("deleteWithNoReply操作错误");
e.printStackTrace();
}
}
/**
* @param key
* @return
*/
public Counter getCounter(String key) {
return getCounter(key,0);
}
/**
* @param key
* @param init
* @return
*/
public Counter getCounter(String key,int init) {
Counter counter = memcachedClient.getCounter(key,init);
return counter;
}
/**
*
*/
public void flushAll(){
try {
memcachedClient.flushAll();
} catch (TimeoutException e) {
log.error("flushAll超时");
e.printStackTrace();
} catch (InterruptedException e) {
log.error("flushAll中断异常");
e.printStackTrace();
} catch (MemcachedException e) {
log.error("flushAll操作错误");
e.printStackTrace();
}
}
public void shutdown(){
try {
memcachedClient.shutdown();
} catch (IOException e) {
log.error("客户端关闭异常");
e.printStackTrace();
}
}
/* (non-Javadoc)
* @see java.lang.Object#finalize()
*/
@Override
protected void finalize() {
try {
memcachedClient.shutdown();
} catch (IOException e) {
log.error("memcached 关闭客户端连接失败！");
e.printStackTrace();
}
}
}
创建测试类：
package bootstrap;
import java.util.concurrent.TimeoutException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import bootstrap.client.MemcachedFailureClient;
import net.rubyeye.xmemcached.Counter;
import net.rubyeye.xmemcached.exception.MemcachedException;
/**
* Memcached Failure 模式客户端测试类
* @author
* donald
* 2017年10月10日
* 下午12:49:45
*/
public class MemcachedFailureClientTest {
private static final Logger log = LoggerFactory.getLogger(MemcachedFailureClientTest.class);
public static void main(String[] args) {
MemcachedFailureClient memcachedClient = MemcachedFailureClient.getInstance();
memcachedClient.set("name", 0, "donald");
String value = (String) memcachedClient.get("name");
log.info("set name={}", value);
memcachedClient.delete("name");
value = (String) memcachedClient.get("name");
log.info("delete name={}", value);
if (!memcachedClient.set("name", 0, "jamel")) {
log.error("set error");
}
value = (String) memcachedClient.get("name");
log.info("set name={}", value);
if (memcachedClient.add("name", 0, "donald")) {
log.error("Add error,key is existed");
}
value = (String) memcachedClient.get("name");
log.info("name={}", value);
if (!memcachedClient.replace("name", 0, "rain")) {
log.error("replace error");
}
value = (String) memcachedClient.get("name");
log.info("repalce name={}", value);
memcachedClient.append("name", "-han");
value = (String) memcachedClient.get("name");
log.info("append name={}", value);
memcachedClient.prepend("name", "0-");
value = (String) memcachedClient.get("name");
log.info("prepend name={}", value);
memcachedClient.touch("name", 3);
try {
Thread.sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
value = (String) memcachedClient.get("name");
log.info("after touch name={}", value);
memcachedClient.deleteWithNoReply("name");
memcachedClient.set("age", 0, "27");
log.info("age={}", memcachedClient.get("age"));
memcachedClient.incr("age", 2, 1);// age 增加2，age不存在，则为1
memcachedClient.incr("age", 1);
log.info("incr age={}", memcachedClient.get("age"));
memcachedClient.decr("age", 2);
log.info("decr age={}", memcachedClient.get("age"));
if (!memcachedClient.cas("age", 27)) {
log.error("cas error");
}
log.info("cas age={}", memcachedClient.get("age"));
Counter counter = memcachedClient.getCounter("counter", 0);
try {
log.info("incrementAndGet counter,{}", counter.incrementAndGet());
log.info("decrementAndGet counter,{}", counter.decrementAndGet());
log.info("addAndGet counter,{}", counter.addAndGet(3));
} catch (MemcachedException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
} catch (TimeoutException e) {
e.printStackTrace();
}
memcachedClient.shutdown();
}
}
运行测试类，控制台输出如下：
12:45:18.135 [main] INFO net.rubyeye.xmemcached.XMemcachedClient 729- XMemcachedClient is using Text protocol 12:45:18.454 [main] INFO net.rubyeye.xmemcached.XMemcachedClient 744- XMemcachedClient in failure mode. 12:45:18.456 [main] INFO com.google.code.yanf4j.nio.impl.SelectorManager 37- Creating 4 reactors... 12:45:18.698 [main] INFO com.google.code.yanf4j.core.impl.AbstractController 377- The Controller started at localhost/127.0.0.1:0 ... 12:45:27.827 [Xmemcached-Reactor-0] INFO com.google.code.yanf4j.core.impl.AbstractController 253- Add a session: 192.168.126.128:11211 12:45:36.882 [Xmemcached-Reactor-0] INFO com.google.code.yanf4j.core.impl.AbstractController 290- Add a standby session: 192.168.126.128:11213 for 192.168.126.128:11211 12:45:45.904 [Xmemcached-Reactor-0] INFO com.google.code.yanf4j.core.impl.AbstractController 253- Add a session: 192.168.126.128:11212 12:45:54.927 [Xmemcached-Reactor-0] INFO com.google.code.yanf4j.core.impl.AbstractController 290- Add a standby session: 192.168.126.128:11214 for 192.168.126.128:11212 12:45:54.993 [main] INFO bootstrap.MemcachedFailureClientTest 25- set name=donald 12:45:55.014 [main] INFO bootstrap.MemcachedFailureClientTest 28- delete name=null 12:45:55.015 [main] INFO bootstrap.MemcachedFailureClientTest 33- set name=jamel 12:45:55.016 [main] INFO bootstrap.MemcachedFailureClientTest 38- name=jamel 12:45:55.017 [main] INFO bootstrap.MemcachedFailureClientTest 43- repalce name=rain 12:45:55.018 [main] INFO bootstrap.MemcachedFailureClientTest 46- append name=rain-han 12:45:55.020 [main] INFO bootstrap.MemcachedFailureClientTest 49- prepend name=0-rain-han 12:45:58.022 [main] INFO bootstrap.MemcachedFailureClientTest 57- after touch name=null 12:45:58.023 [main] INFO bootstrap.MemcachedFailureClientTest 60- age=27 12:45:58.045 [main] INFO bootstrap.MemcachedFailureClientTest 63- incr age=30 12:45:58.047 [main] INFO bootstrap.MemcachedFailureClientTest 65- decr age=28 12:45:58.050 [main] INFO bootstrap.MemcachedFailureClientTest 69- cas age=27 12:45:58.054 [main] INFO bootstrap.MemcachedFailureClientTest 72- incrementAndGet counter,1 12:45:58.055 [main] INFO bootstrap.MemcachedFailureClientTest 73- decrementAndGet counter,0 12:45:58.056 [main] INFO bootstrap.MemcachedFailureClientTest 74- addAndGet counter,3 12:45:58.089 [Xmemcached-Reactor-2] INFO com.google.code.yanf4j.core.impl.AbstractController 368- Remove a session: 192.168.126.128:11211 12:45:58.090 [Xmemcached-Reactor-1] INFO com.google.code.yanf4j.core.impl.AbstractController 368- Remove a session: 192.168.126.128:11212 12:45:58.091 [main] INFO com.google.code.yanf4j.core.impl.AbstractController 486- Controller has been stopped.
从控制台输出来看192.168.126.128:11211的备节点为192.168.126.128:11213，
192.168.126.128:11212的备节点为192.168.126.128:11214。
分别登陆11211,11212,11213,11214实例：
[memcached@donald ~]$ telnet 192.168.126.128 11211 Trying 192.168.126.128... Connected to 192.168.126.128. Escape character is '^]'. get name END get age END get counter VALUE counter 0 1 3 END [memcached@donald ~]$ telnet 192.168.126.128 11212 Trying 192.168.126.128... Connected to 192.168.126.128. Escape character is '^]'. get name END get age VALUE age 512 1 END get counter END [memcached@donald ~]$ telnet 192.168.126.128 11213 Trying 192.168.126.128... Connected to 192.168.126.128. Escape character is '^]'. get name END get age END get counter END [memcached@donald ~]$ telnet 192.168.126.128 11214 Trying 192.168.126.128... Connected to 192.168.126.128. Escape character is '^]'. get nage END get name END get age END get counter END
从上面可以看出age和counter属性存储在主节点11211和11212上，对应的备节点11213和11214上面不存储数据。
新建测试类2：
package bootstrap;
import java.util.concurrent.TimeoutException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import bootstrap.client.MemcachedFailureClient;
import net.rubyeye.xmemcached.Counter;
import net.rubyeye.xmemcached.exception.MemcachedException;
/**
* Memcached Failure 模式客户端测试类
* @author
* donald
* 2017年10月10日
* 下午12:49:45
*/
public class MemcachedFailureClient2Test {
private static final Logger log = LoggerFactory.getLogger(MemcachedFailureClient2Test.class);
public static void main(String[] args) {
MemcachedFailureClient memcachedClient = MemcachedFailureClient.getInstance();
memcachedClient.flushAll();
memcachedClient.set("name", 0, "donald");
String value = (String) memcachedClient.get("name");
log.info("set name={}", value);
memcachedClient.set("age", 0, "27");
log.info("age={}", memcachedClient.get("age"));
memcachedClient.incr("age", 1);
log.info("incr age={}", memcachedClient.get("age"));//debug breakpoint
memcachedClient.set("sex", "man");
try {
Thread.sleep(180000);
} catch (InterruptedException e1) {
e1.printStackTrace();
}
Counter counter = memcachedClient.getCounter("counter", 0);
try {
log.info("incrementAndGet counter,{}", counter.incrementAndGet());
log.info("decrementAndGet counter,{}", counter.decrementAndGet());
log.info("addAndGet counter,{}", counter.addAndGet(3));
} catch (MemcachedException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
} catch (TimeoutException e) {
e.printStackTrace();
}
memcachedClient.shutdown();
}
}
在debug breakpoint添加断点，并以debug模式运行，在到达断点时kill 11211 实例，
控制台输出：
13:08:33.393 [main] INFO net.rubyeye.xmemcached.XMemcachedClient 729- XMemcachedClient is using Text protocol 13:08:33.434 [main] INFO net.rubyeye.xmemcached.XMemcachedClient 744- XMemcachedClient in failure mode. 13:08:33.435 [main] INFO com.google.code.yanf4j.nio.impl.SelectorManager 37- Creating 4 reactors... 13:08:33.452 [main] INFO com.google.code.yanf4j.core.impl.AbstractController 377- The Controller started at localhost/127.0.0.1:0 ... 13:08:42.486 [Xmemcached-Reactor-0] INFO com.google.code.yanf4j.core.impl.AbstractController 253- Add a session: 192.168.126.128:11211 13:08:51.505 [Xmemcached-Reactor-0] INFO com.google.code.yanf4j.core.impl.AbstractController 290- Add a standby session: 192.168.126.128:11213 for 192.168.126.128:11211 13:09:00.526 [Xmemcached-Reactor-0] INFO com.google.code.yanf4j.core.impl.AbstractController 253- Add a session: 192.168.126.128:11212 13:09:09.549 [Xmemcached-Reactor-0] INFO com.google.code.yanf4j.core.impl.AbstractController 290- Add a standby session: 192.168.126.128:11214 for 192.168.126.128:11212 13:09:09.563 [main] INFO bootstrap.MemcachedFailureClient2Test 26- set name=donald 13:09:09.566 [main] INFO bootstrap.MemcachedFailureClient2Test 28- age=27 13:09:09.568 [main] INFO bootstrap.MemcachedFailureClient2Test 30- incr age=28 分别登陆11211,11212,11213,11214实例： [memcached@donald ~]$ telnet 192.168.126.128 11211 Trying 192.168.126.128... Connected to 192.168.126.128. Escape character is '^]'. get name END get age END [memcached@donald ~]$ [memcached@donald ~]$ telnet 192.168.126.128 11212 Trying 192.168.126.128... Connected to 192.168.126.128. Escape character is '^]'. get name VALUE name 0 6 donald END get age VALUE age 0 2 28 END [memcached@donald ~]$ telnet 192.168.126.128 11213 Trying 192.168.126.128... Connected to 192.168.126.128. Escape character is '^]'. get name END get age END [memcached@donald ~]$ telnet 192.168.126.128 11214 Trying 192.168.126.128... Connected to 192.168.126.128. Escape character is '^]'. get name END get age END
关闭11211实例：
[memcached@donald ~]$ ps -ef | grep memcached root 4159 1243 0 08:53 ? 00:00:00 sshd: memcached [priv] memcach+ 4161 4159 0 08:53 ? 00:00:00 sshd: memcached@pts/1 memcach+ 4288 1 0 08:54 ? 00:00:00 memcached -p 11211 -d -u memcached -l 192.168.126.128 -c 1024 memcach+ 4299 1 0 08:54 ? 00:00:00 memcached -p 11212 -d -u memcached -l 192.168.126.128 -c 1024 memcach+ 4310 1 0 08:54 ? 00:00:00 memcached -p 11213 -d -u memcached -l 192.168.126.128 -c 1024 memcach+ 4329 1 0 08:55 ? 00:00:00 memcached -p 11214 -d -u memcached -l 192.168.126.128 -c 1024 memcach+ 4340 4163 0 08:55 pts/1 00:00:00 grep --color=auto memcached [memcached@donald ~]$ kill -9 4288 [memcached@donald ~]$ kill -9 4288 -bash: kill: (4288) - No such process [memcached@donald ~]$ ps -ef | grep memcached root 4159 1243 0 08:53 ? 00:00:00 sshd: memcached [priv] memcach+ 4161 4159 0 08:53 ? 00:00:00 sshd: memcached@pts/1,pts/2,pts/3,pts/4,pts/5 memcach+ 4299 1 0 08:54 ? 00:00:04 memcached -p 11212 -d -u memcached -l 192.168.126.128 -c 1024 memcach+ 4310 1 0 08:54 ? 00:00:04 memcached -p 11213 -d -u memcached -l 192.168.126.128 -c 1024 memcach+ 4329 1 0 08:55 ? 00:00:04 memcached -p 11214 -d -u memcached -l 192.168.126.128 -c 1024 memcach+ 10588 4163 0 13:12 pts/1 00:00:00 grep --color=auto memcached [memcached@donald ~]$
继续执行程序：
分别在11212,11213,11214，获取sex和counter属性：
[memcached@donald ~]$ telnet 192.168.126.128 11211 Trying 192.168.126.128... Connected to 192.168.126.128. Escape character is '^]'. get name END get age END Connection closed by foreign host. [memcached@donald ~]$ [memcached@donald ~]$ telnet 192.168.126.128 11212 Trying 192.168.126.128... Connected to 192.168.126.128. Escape character is '^]'. get name VALUE name 0 6 donald END get age VALUE age 0 2 28 END get sex END get counter END [memcached@donald ~]$ telnet 192.168.126.128 11213 Trying 192.168.126.128... Connected to 192.168.126.128. Escape character is '^]'. get name END get age END get sex VALUE sex 0 3 man END get counter VALUE counter 0 1 3 END [memcached@donald ~]$ telnet 192.168.126.128 11214 Trying 192.168.126.128... Connected to 192.168.126.128. Escape character is '^]'. get name END get age END get sex END get counter END
控制台输出：
13:12:02.932 [Xmemcached-Reactor-2] WARN com.google.code.yanf4j.core.impl.AbstractController 363- Client in failure mode,we don't remove session 192.168.126.128:11211 13:12:04.935 [Heal-Session-Thread] INFO com.google.code.yanf4j.core.impl.AbstractController 129- Trying to connect to 192.168.126.128:11211 for 1 times 13:12:05.962 [Heal-Session-Thread] ERROR com.google.code.yanf4j.core.impl.AbstractController 173- Reconnected to /192.168.126.128:11211 fail 13:12:05.993 [Xmemcached-Reactor-0] ERROR com.google.code.yanf4j.core.impl.AbstractController 562- Exception occured in controller java.io.IOException: Connect to 192.168.126.128:11211 fail,Connection refused: no further information at net.rubyeye.xmemcached.impl.MemcachedConnector.onConnect(MemcachedConnector.java:426) at com.google.code.yanf4j.nio.impl.Reactor.dispatchEvent(Reactor.java:331) at com.google.code.yanf4j.nio.impl.Reactor.run(Reactor.java:180) 13:12:05.993 [Xmemcached-Reactor-0] ERROR remoting 353- Reactor dispatch events error java.io.IOException: Connect to 192.168.126.128:11211 fail,Connection refused: no further information at net.rubyeye.xmemcached.impl.MemcachedConnector.onConnect(MemcachedConnector.java:426) at com.google.code.yanf4j.nio.impl.Reactor.dispatchEvent(Reactor.java:331) at com.google.code.yanf4j.nio.impl.Reactor.run(Reactor.java:180) 13:12:07.970 [Heal-Session-Thread] INFO com.google.code.yanf4j.core.impl.AbstractController 129- Trying to connect to 192.168.126.128:11211 for 2 times 13:12:08.975 [Heal-Session-Thread] ERROR com.google.code.yanf4j.core.impl.AbstractController 173- Reconnected to /192.168.126.128:11211 fail 13:12:08.975 [Xmemcached-Reactor-0] ERROR com.google.code.yanf4j.core.impl.AbstractController 562- Exception occured in controller java.io.IOException: Connect to 192.168.126.128:11211 fail,Connection refused: no further information at net.rubyeye.xmemcached.impl.MemcachedConnector.onConnect(MemcachedConnector.java:426) at com.google.code.yanf4j.nio.impl.Reactor.dispatchEvent(Reactor.java:331) at com.google.code.yanf4j.nio.impl.Reactor.run(Reactor.java:180) 13:12:08.976 [Xmemcached-Reactor-0] ERROR remoting 353- Reactor dispatch events error java.io.IOException: Connect to 192.168.126.128:11211 fail,Connection refused: no further information at net.rubyeye.xmemcached.impl.MemcachedConnector.onConnect(MemcachedConnector.java:426) at com.google.code.yanf4j.nio.impl.Reactor.dispatchEvent(Reactor.java:331) at com.google.code.yanf4j.nio.impl.Reactor.run(Reactor.java:180) 13:12:09.573 [main] INFO bootstrap.MemcachedFailureClient2Test 39- incrementAndGet counter,1 13:12:09.574 [main] INFO bootstrap.MemcachedFailureClient2Test 40- decrementAndGet counter,0 13:12:09.575 [main] INFO bootstrap.MemcachedFailureClient2Test 41- addAndGet counter,3 13:12:09.577 [Xmemcached-Reactor-1] INFO com.google.code.yanf4j.core.impl.AbstractController 368- Remove a session: 192.168.126.128:11212 13:12:09.578 [main] INFO com.google.code.yanf4j.core.impl.AbstractController 486- Controller has been stopped.
从上面可以看出，当主节点11211宕机时，其备节点升级为主节点。