memcached缓存编程实战

北风网项目培训讲师：tom5（北风网)QQ：754026446第十三讲memcached缓存编程实战memcached

client

for

java是一个memcached

Java客户端API，应用广泛，运行比较稳定。Jar包下载地址：引用包：<%@

page

import="com.danga.MemCached.*"

%>初始化池：String[]

servers

=

{

"192.168.134.139:11211"

};Integer[]

weights

=

{

3

};MemCachedClient

mcc

=

new

MemCachedClient();SockIOPool

pool

=

SockIOPool.getInstance();pool.setServers(servers);pool.setWeights(weights);pool.setInitConn(5);pool.setMinConn(5);pool.setMaxConn(250);pool.setMaxIdle(30);pool.setMaintSleep(30);pool.initialize();添加内容for

(int

i

=

1;

i

<=

3;

i++)

{//如果以前存在，则不去更新boolean

b

=

mcc.add("key"

+

i,

"value"

+

i);out.println("<br>key"

+

i

+"

-

result:

"

+

b);}//最后关闭池

pool.shutDown();获取某键值内容Object

obj

=

mcc.get("key2");out.println("<br>key2

-

result:

"+obj);替换某键值内容：//如果key不存在，则返回flase，更新失败

boolean

b=mcc.replace("key2","newValue");out.println("<br>update"+b);删除某键值内容Object

key3

=

mcc.get("key3");out.println(“<br>key3:"

+

key3);mcc.delete("key3");out.println("<br>after

delete");Object

key3now

=

mcc.get("key3");out.println("<br>key3-

now

result:"

+

key3now);查看每个slab中存储的item的一些详细信息stats

itemsSTAT

items:1:number

2STAT

items:1:age4614STATitems:1:evicted0如果一个slab的evicted属性不是0，则说明当前slab出现了提前剔除数据的情况STAT

items:1:evicted_nonzero

0STAT

items:1:evicted_time

0STAT

items:1:outofmemory

0STAT

items:1:tailrepairs

0END查看slab中内存分配的情况STAT

1:chunk_size

96当前slab每个chunk的大小STAT

1:chunks_per_page

10922每个page能够存放的chunk数STAT

1:total_pages

1分配给当前slab的page总数STAT

1:total_chunks10922

当前slab最多能够存放的chunk数，应该等于chunck_per_page

*

total_pageSTAT

1:used_chunks

2

已经被占用的chunks总数STAT

1:free_chunks

2

过期数据空出的chunk里还没有被使用的chunk数STAT

1:free_chunks_end

10918新分配的但是还没有被使用的chunk数STAT

1:mem_requested

154STAT

1:get_hits

3STAT

1:cmd_set

11STAT

1:delete_hits

1STAT

1:incr_hits0STAT

1:decr_hits

0STAT

1:cas_hits

0STAT

1:cas_badval

0STAT

active_slabs

1STAT

total_malloced

1048512END

long

i

=

1;Object

obj

=

mcc.get("count");if

(obj!=null)

{i

=((Long)obj).longValue();i++;mcc.replace("count",

Long.valueOf(i));}else{//firstmcc.add("count",

Long.valueOf(i));}out.println(