转摘memcache
一、概念
Memcached是danga.com(运营LiveJournal的技术团队)开发的一套分布式内存对象缓存系统,用于在动态系统中减少数据库负载,提升性能。
二、适用场合
1.分布式应用。由于memcached本身基于分布式的系统,所以尤其适合大型的分布式系统。
2.数据库前段缓存。数据库常常是网站系统的瓶颈。数据库的大并发量访问,常常造成网站内存溢出。当然我们也可以使用Hibernate的缓存机制。但memcached是基于分布式的,并可独立于网站应用本身,所以更适合大型网站进行应用的拆分。
3.服务器间数据共享。举例来讲,我们将网站的登录系统、查询系统拆分为两个应用,放在不同的服务器上,并进行集群,那这个时候用户登录后,登录信息如何从登录系统服务器同步到查询系统服务器呢?这时候,我们便可以使用memcached,登录系统将登录信息缓存起来,查询系统便可以获得登录信息,就像获取本地信息一样。
三、不适用场合
那些不需要“分布”的,不需要共享的,或者干脆规模小到只有一台服务器的应用,memcached不会带来任何好处,相反还会拖慢系统效率,因为网络连接同样需要资源
四、安装
这里介绍windows环境的安装。
1.下载memcache的windows稳定版,解压放某个盘下面,比如在c:\memcached
2.在cmd下输入'c:\memcached\memcached.exe-dinstall'安装
3.再输入:'c:\memcached\memcached.exe-dstart'启动。
以后memcached将作为windows的一个服务每次开机时自动启动。这样服务器端已经安装完毕了。
五、客户端
Memcached本身是使用C开发的,客户端可以是php、C#、或者java。我是做java的,所以这里只介绍基于java的客户端。
我在网上看到基于java的客户端有两个
1.java_memcached-release_2.6.3
1)简介
这是比较通用的Memcached客户端框架。具体原创不详。
2)依赖的jar
A.commons-pool-1.5.6.jar
B.java_memcached-release_2.6.3.jar
C.slf4j-api-1.6.1.jar
D.slf4j-simple-1.6.1.jar
2.alisoft-xplatform-asf-cache-2.5.1
1)简介
这个东东是阿里软件的架构师岑文初进行封装的。里面的注释都是中文的,比较好。
2)依赖的jar
A.alisoft-xplatform-asf-cache-2.5.1.jar
B.commons-logging-1.0.4.jar
C.hessian-3.0.1.jar
D.log4j-1.2.9.jar
E.stax-api-1.0.1.jar
F.wstx-asl-2.0.2.jar
六、范例
1.基于java_memcached-release_2.6.3
Java代码收藏代码
1.packagecom.hl.memcached.cache;
2.
3.importjava.util.Date;
4.
5.importcom.danga.MemCached.MemCachedClient;
6.importcom.danga.MemCached.SockIOPool;
7.
8.publicclassMyCache{
9.publicstaticvoidmain(String[]args){
10.MemCachedClientclient=newMemCachedClient();
11.String[]addr={"127.0.0.1:11211"};
12.Integer[]weights={3};
13.SockIOPoolpool=SockIOPool.getInstance();
14.pool.setServers(addr);
15.pool.setWeights(weights);
16.pool.setInitConn(5);
17.pool.setMinConn(5);
18.pool.setMaxConn(200);
19.pool.setMaxIdle(1000*30*30);
20.pool.setMaintSleep(30);
21.pool.setNagle(false);
22.pool.setSocketTO(30);
23.pool.setSocketConnectTO(0);
24.pool.initialize();
25.
26.//String[]s=pool.getServers();
27.client.setCompressEnable(true);
28.client.setCompressThreshold(1000*1024);
29.
30.//将数据放入缓存
31.client.set("test2","test2");
32.
33.//将数据放入缓存,并设置失效时间
34.Datedate=newDate(2000000);
35.client.set("test1","test1",date);
36.
37.//删除缓存数据
38.//client.delete("test1");
39.
40.//获取缓存数据
41.Stringstr=(String)client.get("test1");
42.System.out.println(str);
43.}
44.}
packagecom.hl.memcached.cache;
importjava.util.Date;
importcom.danga.MemCached.MemCachedClient;
importcom.danga.MemCached.SockIOPool;
publicclassMyCache{
publicstaticvoidmain(String[]args){
MemCachedClientclient=newMemCachedClient();
String[]addr={"127.0.0.1:11211"};
Integer[]weights={3};
SockIOPoolpool=SockIOPool.getInstance();
pool.setServers(addr);
pool.setWeights(weights);
pool.setInitConn(5);
pool.setMinConn(5);
pool.setMaxConn(200);
pool.setMaxIdle(1000*30*30);
pool.setMaintSleep(30);
pool.setNagle(false);
pool.setSocketTO(30);
pool.setSocketConnectTO(0);
pool.initialize();
//String[]s=pool.getServers();
client.setCompressEnable(true);
client.setCompressThreshold(1000*1024);
//将数据放入缓存
client.set("test2","test2");
//将数据放入缓存,并设置失效时间
Datedate=newDate(2000000);
client.set("test1","test1",date);
//删除缓存数据
//client.delete("test1");
//获取缓存数据
Stringstr=(String)client.get("test1");
System.out.println(str);
}
}
2.基于alisoft-xplatform-asf-cache-2.5.1
1)配置memcached.xml
Xml代码收藏代码
1.<?xmlversion="1.0"encoding="UTF-8"?>
2.<memcached>
3.<!--name属性是程序中使用Cache的唯一标识;socketpool属性将会关联到后面的socketpool配置;-->
4.<clientname="mclient_0"compressEnable="true"defaultEncoding="UTF-8"
5.socketpool="pool_0">
6.<!--可选,用来处理出错情况-->
7.<errorHandler>com.alisoft.xplatform.asf.cache.memcached.MemcachedErrorHandler
8.</errorHandler>
9.</client>
10.
11.<!--
12.name属性和client配置中的socketpool属性相关联。
13.maintSleep属性是后台线程管理SocketIO池的检查间隔时间,如果设置为0,则表明不需要后台线程维护SocketIO线程池,默认需要管理。
14.socketTO属性是Socket操作超时配置,单位ms。aliveCheck
15.属性表示在使用Socket以前是否先检查Socket状态。
16.-->
17.<socketpoolname="pool_0"maintSleep="5000"socketTO="3000"
18.failover="true"aliveCheck="true"initConn="5"minConn="5"maxConn="250"
19.nagle="false">
20.<!--设置memcache服务端实例地址.多个地址用","隔开-->
21.<servers>127.0.0.1:11211</servers>
22.<!--
23.可选配置。表明了上面设置的服务器实例的Load权重.例如<weights>3,7</weights>表示30%load在
24.10.2.224.36:33001,70%load在10.2.224.46:33001
25.
26.<weights>3,7</weights>
27.-->
28.</socketpool>
29.</memcached>
<?xmlversion="1.0"encoding="UTF-8"?>
<memcached>
<!--name属性是程序中使用Cache的唯一标识;socketpool属性将会关联到后面的socketpool配置;-->
<clientname="mclient_0"compressEnable="true"defaultEncoding="UTF-8"
socketpool="pool_0">
<!--可选,用来处理出错情况-->
<errorHandler>com.alisoft.xplatform.asf.cache.memcached.MemcachedErrorHandler
</errorHandler>
</client>
<!--
name属性和client配置中的socketpool属性相关联。
maintSleep属性是后台线程管理SocketIO池的检查间隔时间,如果设置为0,则表明不需要后台线程维护SocketIO线程池,默认需要管理。
socketTO属性是Socket操作超时配置,单位ms。aliveCheck
属性表示在使用Socket以前是否先检查Socket状态。
-->
<socketpoolname="pool_0"maintSleep="5000"socketTO="3000"
failover="true"aliveCheck="true"initConn="5"minConn="5"maxConn="250"
nagle="false">
<!--设置memcache服务端实例地址.多个地址用","隔开-->
<servers>127.0.0.1:11211</servers>
<!--
可选配置。表明了上面设置的服务器实例的Load权重.例如<weights>3,7</weights>表示30%load在
10.2.224.36:33001,70%load在10.2.224.46:33001
<weights>3,7</weights>
-->
</socketpool>
</memcached>
2)测试类
Java代码收藏代码
1.packagecom.hl.memcached.client.test;
2.
3.importjava.util.ArrayList;
4.importjava.util.List;
5.
6.importcom.alisoft.xplatform.asf.cache.ICacheManager;
7.importcom.alisoft.xplatform.asf.cache.IMemcachedCache;
8.importcom.alisoft.xplatform.asf.cache.memcached.CacheUtil;
9.importcom.alisoft.xplatform.asf.cache.memcached.MemcachedCacheManager;
10.importcom.hl.memcached.cache.client.TestBean;
11.
12.publicclassClientTest{
13.
14.@SuppressWarnings("unchecked")
15.publicstaticvoidmain(String[]args){
16.ICacheManager<IMemcachedCache>manager;
17.manager=CacheUtil.getCacheManager(IMemcachedCache.class,
18.MemcachedCacheManager.class.getName());
19.manager.setConfigFile("memcached.xml");
20.manager.start();
21.try{
22.IMemcachedCachecache=manager.getCache("mclient_0");
23.cache.put("key","value");
24.System.out.println(cache.get("key"));
25.}finally{
26.manager.stop();
27.}
28.}
29.
30.}
packagecom.hl.memcached.client.test;
importjava.util.ArrayList;
importjava.util.List;
importcom.alisoft.xplatform.asf.cache.ICacheManager;
importcom.alisoft.xplatform.asf.cache.IMemcachedCache;
importcom.alisoft.xplatform.asf.cache.memcached.CacheUtil;
importcom.alisoft.xplatform.asf.cache.memcached.MemcachedCacheManager;
importcom.hl.memcached.cache.client.TestBean;
publicclassClientTest{
@SuppressWarnings("unchecked")
publicstaticvoidmain(String[]args){
ICacheManager<IMemcachedCache>manager;
manager=CacheUtil.getCacheManager(IMemcachedCache.class,
MemcachedCacheManager.class.getName());
manager.setConfigFile("memcached.xml");
manager.start();
try{
IMemcachedCachecache=manager.getCache("mclient_0");
cache.put("key","value");
System.out.println(cache.get("key"));
}finally{
manager.stop();
}
}
}
七、使用memcached缓存javabean自定义对象
Memcached可以缓存String,也可以缓存自定义javabean。但必须是可序列化的javabean(implementsSerializable即可)
1.基于java_memcached-release_2.6.3
测试用javabean
Java代码收藏代码
1.packagecom.hl.memcached.cache.client;
2.
3.importjava.io.Serializable;
4.
5.publicclassTestBeanimplementsSerializable{
6.privatestaticfinallongserialVersionUID=5344571864700659321L;
7.
8.privateStringname;
9.privateIntegerage;
10.//get、set方法略
11.}
packagecom.hl.memcached.cache.client;
importjava.io.Serializable;
publicclassTestBeanimplementsSerializable{
privatestaticfinallongserialVersionUID=5344571864700659321L;
privateStringname;
privateIntegerage;
//get、set方法略
}
MyCache.java代码
Java代码收藏代码
1.packagecom.hl.memcached.cache;
2.
3.importjava.util.Date;
4.
5.importcom.danga.MemCached.MemCachedClient;
6.importcom.danga.MemCached.SockIOPool;
7.
8.publicclassMyCache{
9.publicstaticvoidmain(String[]args){
10.MemCachedClientclient=newMemCachedClient();
11.String[]addr={"127.0.0.1:11211"};
12.Integer[]weights={3};
13.SockIOPoolpool=SockIOPool.getInstance();
14.pool.setServers(addr);
15.pool.setWeights(weights);
16.pool.setInitConn(5);
17.pool.setMinConn(5);
18.pool.setMaxConn(200);
19.pool.setMaxIdle(1000*30*30);
20.pool.setMaintSleep(30);
21.pool.setNagle(false);
22.pool.setSocketTO(30);
23.pool.setSocketConnectTO(0);
24.pool.initialize();
25.
26.//String[]s=pool.getServers();
27.client.setCompressEnable(true);
28.client.setCompressThreshold(1000*1024);
29.
30.//将数据放入缓存
31.TestBeanbean=newTestBean();
32.bean.setName("name1");
33.bean.setAge(25);
34.client.add("bean1",bean);
35.
36.//获取缓存数据
37.TestBeanbeanClient=(TestBean)client.get("bean1");
38.System.out.println(beanClient.getName());
39.}
40.}
packagecom.hl.memcached.cache;
importjava.util.Date;
importcom.danga.MemCached.MemCachedClient;
importcom.danga.MemCached.SockIOPool;
publicclassMyCache{
publicstaticvoidmain(String[]args){
MemCachedClientclient=newMemCachedClient();
String[]addr={"127.0.0.1:11211"};
Integer[]weights={3};
SockIOPoolpool=SockIOPool.getInstance();
pool.setServers(addr);
pool.setWeights(weights);
pool.setInitConn(5);
pool.setMinConn(5);
pool.setMaxConn(200);
pool.setMaxIdle(1000*30*30);
pool.setMaintSleep(30);
pool.setNagle(false);
pool.setSocketTO(30);
pool.setSocketConnectTO(0);
pool.initialize();
//String[]s=pool.getServers();
client.setCompressEnable(true);
client.setCompressThreshold(1000*1024);
//将数据放入缓存
TestBeanbean=newTestBean();
bean.setName("name1");
bean.setAge(25);
client.add("bean1",bean);
//获取缓存数据
TestBeanbeanClient=(TestBean)client.get("bean1");
System.out.println(beanClient.getName());
}
}
2.基于alisoft-xplatform-asf-cache-2.5.1
Java代码收藏代码
1.packagecom.hl.memcached.client.test;
2.
3.importjava.util.ArrayList;
4.importjava.util.List;
5.
6.importcom.alisoft.xplatform.asf.cache.ICacheManager;
7.importcom.alisoft.xplatform.asf.cache.IMemcachedCache;
8.importcom.alisoft.xplatform.asf.cache.memcached.CacheUtil;
9.importcom.alisoft.xplatform.asf.cache.memcached.MemcachedCacheManager;
10.importcom.hl.memcached.cache.client.TestBean;
11.
12.publicclassClientTest{
13.
14.@SuppressWarnings("unchecked")
15.publicstaticvoidmain(String[]args){
16.ICacheManager<IMemcachedCache>manager;
17.manager=CacheUtil.getCacheManager(IMemcachedCache.class,
18.MemcachedCacheManager.class.getName());
19.manager.setConfigFile("memcached.xml");
20.manager.start();
21.try{
22.IMemcachedCachecache=manager.getCache("mclient_0");
23.
24.TestBeanbean=newTestBean();
25.bean.setName("name1");
26.bean.setAge(25);
27.cache.put("bean",bean);
28.TestBeanbeanClient=(TestBean)cache.get("bean");
29.System.out.println(beanClient.getName());
30.
31.List<TestBean>list=newArrayList<TestBean>();
32.list.add(bean);
33.cache.put("beanList",list);
34.List<TestBean>listClient=(List<TestBean>)cache.get("beanList");
35.if(listClient.size()>0){
36.TestBeanbean4List=listClient.get(0);
37.System.out.println(bean4List.getName());
38.}
39.}finally{
40.manager.stop();
41.}
42.}
43.
44.}
packagecom.hl.memcached.client.test;
importjava.util.ArrayList;
importjava.util.List;
importcom.alisoft.xplatform.asf.cache.ICacheManager;
importcom.alisoft.xplatform.asf.cache.IMemcachedCache;
importcom.alisoft.xplatform.asf.cache.memcached.CacheUtil;
importcom.alisoft.xplatform.asf.cache.memcached.MemcachedCacheManager;
importcom.hl.memcached.cache.client.TestBean;
publicclassClientTest{
@SuppressWarnings("unchecked")
publicstaticvoidmain(String[]args){
ICacheManager<IMemcachedCache>manager;
manager=CacheUtil.getCacheManager(IMemcachedCache.class,
MemcachedCacheManager.class.getName());
manager.setConfigFile("memcached.xml");
manager.start();
try{
IMemcachedCachecache=manager.getCache("mclient_0");
TestBeanbean=newTestBean();
bean.setName("name1");
bean.setAge(25);
cache.put("bean",bean);
TestBeanbeanClient=(TestBean)cache.get("bean");
System.out.println(beanClient.getName());
List<TestBean>list=newArrayList<TestBean>();
list.add(bean);
cache.put("beanList",list);
List<TestBean>listClient=(List<TestBean>)cache.get("beanList");
if(listClient.size()>0){
TestBeanbean4List=listClient.get(0);
System.out.println(bean4List.getName());
}
}finally{
manager.stop();
}
}
}
八、参考资料:
http://blog.developers.api.sina.com.cn/?p=124
http://www.infoq.com/cn/articles/memcached-java
九、源代码及资料见附件
*java_memcached-release_2.6.3资料.rar(191.4KB)
*下载次数:83
*alisoft-xplatform-asf-cache-2.5.1-src资料.rar(1.3MB)
*下载次数:105
*memcached-1.2.1-win32安装文件.rar(82.6KB)
*下载次数:55
*memcached-1.4.13源代码.gz(313.2KB)
*下载次数:63
*demo.rar(1006.6KB)
*下载次数:104