memcache(转)
转：Memcached笔记——（一）安装&常规错误&监控
一、下载
1.Libevent
简单的说就是一个事件触发的网络库，Memcached离不开它。
Shell代码
[*]wget http://cloud.github.com/downloads/libevent/libevent/libevent-2.0.17-stable.tar.gz
2.Memcached
今天的主角
Shell代码
[*]wget http://memcached.googlecode.com/files/memcached-1.4.13.tar.gz
二、安装
1.Libevent
解压缩
Shell代码
[*]tar zxvf libevent-2.0.17-stable.tar.gz
编译、安装
Shell代码
[*]./configure --prefix=/usr && make && make install
这里一定要注意指定--prefix，后面配置memcached的时候就有必要用到。
2.Memcached
解压
Shell代码
[*]tar zxvf memcached-1.4.13.tar.gz
编译、安装
Shell代码
[*]./configure --with-libevent=/usr/lib && make && make install
这里一定要指定libevent的路径，否则启动的时候就有找不到libevent的so文件的错误！
启动
Shell代码
[*]memcached -d -m 512 -p 11211 -u root -c 256 -P /var/run/memcached.pid
参数
引用
-p <num> TCP port number to listen on (default: 11211)
-U <num> UDP port number to listen on (default: 11211, 0 is off)
-l <addr> interface to listen on (default: INADDR_ANY, all addresses)
<addr> may be specified as host:port. If you don't specify
a port number, the value you specified with -p or -U is
used. You may specify multiple addresses separated by comma
or by using -l multiple times
-d run as a daemon
-u <username> assume identity of <username> (only when run as root)
-m <num> max memory to use for items in megabytes (default: 64 MB)
-M return error on memory exhausted (rather than removing items)
-c <num> max simultaneous connections (default: 1024)
-v verbose (print errors/warnings while in event loop)
-P <file> save PID in <file>, only used with -d option
要关掉memcached
Shell代码
[*]kill -9 `cat /var/run/memcached.pid`
是否正常？Telnet上去看看
Shell代码
[*]telnet xxx.xxx.xxx.xxx 11211
然后输入
Shell代码
[*]stats
接着就能看到：
引用
STAT pid 3021
STAT uptime 3621
STAT time 1331261509
STAT version 1.4.13
STAT libevent 2.0.17-stable
STAT pointer_size 64
STAT rusage_user 0.000000
STAT rusage_system 0.000999
STAT curr_connections 6
STAT total_connections 7
STAT connection_structures 7
STAT reserved_fds 20
STAT cmd_get 0
STAT cmd_set 0
STAT cmd_flush 0
STAT cmd_touch 0
STAT get_hits 0
STAT get_misses 0
STAT delete_misses 0
STAT delete_hits 0
STAT incr_misses 0
STAT incr_hits 0
STAT decr_misses 0
STAT decr_hits 0
STAT cas_misses 0
STAT cas_hits 0
STAT cas_badval 0
STAT touch_hits 0
STAT touch_misses 0
STAT auth_cmds 0
STAT auth_errors 0
STAT bytes_read 72
STAT bytes_written 1038
STAT limit_maxbytes 52428800
STAT accepting_conns 1
STAT listen_disabled_num 0
STAT threads 4
STAT conn_yields 0
STAT hash_power_level 16
STAT hash_bytes 524288
STAT hash_is_expanding 0
STAT expired_unfetched 0
STAT evicted_unfetched 0
STAT bytes 0
STAT curr_items 0
STAT total_items 0
STAT evictions 0
STAT reclaimed 0
END
上面状况说明Memcached服务正常。
还可以试试get、set、delete、replace
引用
set foo 0 0 3 （保存命令）
bar （数据）
STORED （结果）
get foo （取得命令）
VALUE foo 0 3 （数据）
bar （数据）
输入
Shell代码
[*]quit
退出。
三、系统服务
参照Nginx的系统服务，自己写了一个Memcached的系统服务脚本。
先构建/etc/init.d/memcahed这个文件，然后赋予其可执行权限：
Shell代码
[*]touch /etc/init.d/memcached
[*]chmod +x /etc/init.d/memcached
memcached脚本如下：
Shell代码
[*]#!/bin/bash
[*]# v.0.0.1
[*]# create by snowolf at 2012.5.25
[*]#
[*]# memcached - This shell script takes care of starting and stopping memcached.
[*]#
[*]# chkconfig: - 90 10
[*]# description: Memcache provides fast memory based storage.
[*]# processname: memcached
[*]
[*]memcached_path="/usr/local/bin/memcached"
[*]memcached_pid="/var/run/memcached.pid"
[*]memcached_memory="1024"
[*]
[*]# Source function library.
[*]. /etc/rc.d/init.d/functions
[*]
[*][ -x $memcached_path ] || exit 0
[*]
[*]RETVAL=0
[*]prog="memcached"
[*]
[*]# Start daemons.
[*]start() {
[*] if [ -e $memcached_pid -a ! -z $memcached_pid ];then
[*] echo $prog" already running...."
[*] exit 1
[*] fi
[*]
[*] echo -n $"Starting $prog "
[*] # Single instance for all caches
[*] $memcached_path -m $memcached_memory -l 0.0.0.0 -p 11211 -u root -d -P $memcached_pid
[*] RETVAL=$?
[*] [ $RETVAL -eq 0 ] && {
[*] touch /var/lock/subsys/$prog
[*] success $"$prog"
[*] }
[*] echo
[*] return $RETVAL
[*]}
[*]
[*]
[*]# Stop daemons.
[*]stop() {
[*] echo -n $"Stopping $prog "
[*] killproc -d 10 $memcached_path
[*] echo
[*] [ $RETVAL = 0 ] && rm -f $memcached_pid /var/lock/subsys/$prog
[*]
[*] RETVAL=$?
[*] return $RETVAL
[*]}
[*]
[*]# See how we were called.
[*]case "$1" in
[*] start)
[*] start
[*] ;;
[*] stop)
[*] stop
[*] ;;
[*] status)
[*] status $prog
[*] RETVAL=$?
[*] ;;
[*] restart)
[*] stop
[*] start
[*] ;;
[*] *)
[*] echo $"Usage: $0 {start|stop|status|restart}"
[*] exit 1
[*]esac
[*]exit $RETVAL
注意这几行配置，请根据实际情况配置memcached执行文件路径，以及Memcached使用内存大小：
引用
memcached_path="/usr/local/bin/memcached"
memcached_memory="1024"
追加为系统服务：
Shell代码
[*]chkconfig --add memcached
[*]chkconfig memcached on
然后就可以通过service memcached start|stop|status|restart控制memcached了！
四、常规错误
一开始没有指定libevent路径安装memcached的时候，启动memcached就报这个错误：
引用
memcached: error while loading shared libraries: libevent-2.0.so.5: cannot open shared object file: No such file or directory
其实这个文件就在/usr/lib下。错就错在Linux是64bit系统，如果没有指定libevent路径，memcached就会去/usr/lib64下去找。
找到这个文件
Shell代码
[*]whereis libevent-2.0.so.5
引用
libevent-2.0.so: /usr/lib/libevent-2.0.so.5
Shell代码
[*]ldd /usr/local/bin/memcached
提示找不到libevent-2.0.so.5
引用
linux-vdso.so.1 => (0x00007fff41dfd000)
libevent-2.0.so.5 => not found
librt.so.1 => /lib64/librt.so.1 (0x0000003c94a00000)
libpthread.so.0 => /lib64/libpthread.so.0 (0x0000003c93a00000)
libc.so.6 => /lib64/libc.so.6 (0x0000003c92e00000)
/lib64/ld-linux-x86-64.so.2 (0x0000003c92a00000)
定位
Shell代码
[*]LD_DEBUG=libs /usr/local/bin/memcached -v
引用
19905: find library=libevent-2.0.so.5 ; searching
19905: search path=/usr/lib/lib/tls/x86_64:/usr/lib/lib/tls:/usr/lib/lib/x86_64:/usr/lib/lib (RPATH from file /usr/local/bin/memcached)
19905: trying file=/usr/lib/lib/tls/x86_64/libevent-2.0.so.5
19905: trying file=/usr/lib/lib/tls/libevent-2.0.so.5
19905: trying file=/usr/lib/lib/x86_64/libevent-2.0.so.5
19905: trying file=/usr/lib/lib/libevent-2.0.so.5
19905: search cache=/etc/ld.so.cache
19905: search path=/lib64/tls/x86_64:/lib64/tls:/lib64/x86_64:/lib64:/usr/lib64/tls/x86_64:/usr/lib64/tls:/usr/lib64/x86_64:/usr/lib64 (system search path)
19905: trying file=/lib64/tls/x86_64/libevent-2.0.so.5
19905: trying file=/lib64/tls/libevent-2.0.so.5
19905: trying file=/lib64/x86_64/libevent-2.0.so.5
19905: trying file=/lib64/libevent-2.0.so.5
19905: trying file=/usr/lib64/tls/x86_64/libevent-2.0.so.5
19905: trying file=/usr/lib64/tls/libevent-2.0.so.5
19905: trying file=/usr/lib64/x86_64/libevent-2.0.so.5
19905: trying file=/usr/lib64/libevent-2.0.so.5
19905:
/usr/local/bin/memcached: error while loading shared libraries: libevent-2.0.so.5: cannot open shared object file: No such file or directory
注意这句：
引用
19905: trying file=/usr/lib64/libevent-2.0.so.5
做个软连接
Shell代码
[*]ln -s /usr/lib/libevent-2.0.so.5 /usr/lib64/libevent-2.0.so.5
再试试：
Shell代码
[*]ldd /usr/local/bin/memcached
这回找到了！
引用
linux-vdso.so.1 => (0x00007fffffef6000)
libevent-2.0.so.5 => /usr/lib64/libevent-2.0.so.5 (0x00002b5608a26000)
librt.so.1 => /lib64/librt.so.1 (0x0000003c94a00000)
libpthread.so.0 => /lib64/libpthread.so.0 (0x0000003c93a00000)
libc.so.6 => /lib64/libc.so.6 (0x0000003c92e00000)
/lib64/ld-linux-x86-64.so.2 (0x0000003c92a00000)
五、监控
可以在服务器上配置一个PHP页面来监测Memcached的情况，
配置也比较简单，主要包括账户配置，以及Memcached Server地址配置。
Php代码
[*]define('ADMIN_USERNAME','memcache'); // Admin Username
[*]define('ADMIN_PASSWORD','password'); // Admin Password
[*]define('DATE_FORMAT','Y/m/d H:i:s');
[*]define('GRAPH_SIZE',200);
[*]define('MAX_ITEM_DUMP',50);
[*]
[*]$MEMCACHE_SERVERS[] = 'mymemcache-server1:11211'; // add more as an array
[*]$MEMCACHE_SERVERS[] = 'mymemcache-server2:11211'; // add more as an array
如果不方便搭建PHP服务，可以使用Perl脚本memcache-top
修改@default_instances或使用--instances参数：
Shell代码
[*]perl memcache-top-v0.6 --instances 10.11.155.26 10.11.155.41
Memcached笔记——（二）XMemcached&Spring集成
一、Memcached Client简要介绍
Memcached Client目前有3种：
[*]Memcached Client for Java
[*]SpyMemcached
[*]XMemcached
这三种Client一直存在各种争议：
[*]Memcached Client for Java 比 SpyMemcached更稳定、更早、更广泛；
[*]SpyMemcached 比 Memcached Client for Java更高效；
[*]XMemcached 比 SpyMemcache并发效果更好。
用数据来说话，参考官方性能对比：
Memcached Client for Java：https://github.com/gwhalin/Memcached-Java-Client/wiki/PERFORMANCE
XMemcached：http://xmemcached.googlecode.com/svn/trunk/benchmark/benchmark.html
二、XMemcached特性
XMemcached特性：
[*]高性能
[*]支持完整的memcached文本协议,二进制协议。
[*]支持JMX，可以通过MBean调整性能参数、动态添加/移除server、查看统计等。
[*]支持客户端统计
[*]支持memcached节点的动态增减。
[*]支持memcached分布:余数分布和一致性哈希分布。
[*]更多的性能调整选项。
此外，XMemcached更容易与Spring集成。而且，属于中国原创！
三、XMemcached简单实现
MemcachedClientBuilder是MemcachedClient核心接口，用来控制Client的构建（build()方法）和关闭（shutdown()方法）。
XMemcachedClientBuilder一般通过构造方法配置地址列表，通常还要配置权重，代码如下：
Java代码
[*]public XMemcachedClientBuilder(List<InetSocketAddress> addressList) {
[*] if (addressList != null) {
[*] for (InetSocketAddress addr : addressList) {
[*] this.addressMap.put(addr, null);
[*] }
[*] }
[*]}
[*]
[*]public XMemcachedClientBuilder(List<InetSocketAddress> addressList,
[*] int[] weights) {
[*] if (addressList != null) {
[*] for (InetSocketAddress addr : addressList) {
[*] this.addressMap.put(addr, null);
[*] }
[*] }
[*] this.weights = weights;
[*]}
不过这哥们如果用this()可以省点代码， 还有给加点注释吧！
此外，还需要设置连接池大小，使用二进制协议/文本协议等。
通过build()方法获得MemcachedClient
然后就可以通过Memcached进行set、get、replace、delete等Memcached操作了！
上代码：
Java代码
[*]import static junit.framework.Assert.*;
[*]
[*]import java.io.IOException;
[*]import java.util.concurrent.TimeoutException;
[*]
[*]import net.rubyeye.xmemcached.MemcachedClient;
[*]import net.rubyeye.xmemcached.MemcachedClientBuilder;
[*]import net.rubyeye.xmemcached.XMemcachedClientBuilder;
[*]import net.rubyeye.xmemcached.command.BinaryCommandFactory;
[*]import net.rubyeye.xmemcached.exception.MemcachedException;
[*]import net.rubyeye.xmemcached.utils.AddrUtil;
[*]
[*]import org.junit.Test;
[*]
[*]public class MemcachedClientTest {
[*] @Test
[*] public void test() {
[*] MemcachedClientBuilder builder = new XMemcachedClientBuilder(
[*] AddrUtil.getAddresses("10.11.155.26:11211 10.11.155.41:11211 10.10.76.31:11211 10.10.76.35:11211"),
[*] new int[] { 1, 1, 1, 1 });
[*]
[*] // 设置连接池大小，即客户端个数
[*] builder.setConnectionPoolSize(50);
[*]
[*] // 宕机报警
[*] builder.setFailureMode(true);
[*]
[*] // 使用二进制文件
[*] builder.setCommandFactory(new BinaryCommandFactory());
[*]
[*] MemcachedClient memcachedClient = null;
[*] try {
[*] memcachedClient = builder.build();
[*] try {
[*] // 设置/获取
[*] memcachedClient.set("zlex", 36000, "set/get");
[*] assertEquals("set/get", memcachedClient.get("zlex"));
[*]
[*] // 替换
[*] memcachedClient.replace("zlex", 36000, "replace");
[*] assertEquals("replace", memcachedClient.get("zlex"));
[*]
[*] // 移除
[*] memcachedClient.delete("zlex");
[*] assertNull(memcachedClient.get("zlex"));
[*] } catch (TimeoutException e) {
[*] // TODO Auto-generated catch block
[*] e.printStackTrace();
[*] } catch (InterruptedException e) {
[*] // TODO Auto-generated catch block
[*] e.printStackTrace();
[*] } catch (MemcachedException e) {
[*] // TODO Auto-generated catch block
[*] e.printStackTrace();
[*] }
[*]
[*] } catch (IOException e) {
[*] // TODO Auto-generated catch block
[*] e.printStackTrace();
[*] } finally {
[*] if (memcachedClient != null) {
[*] try {
[*] memcachedClient.shutdown();
[*] } catch (IOException e) {
[*] // TODO Auto-generated catch block
[*] e.printStackTrace();
[*] }
[*] }
[*] }
[*] }
[*]}
四、XMemcached与Spring集成
XMemcached与Spring集成可以参考http://code.google.com/p/xmemcached/wiki/Spring_Integration，这里只说最常用的方法。
memcached.properties做基本配置：
Properties代码
[*]#连接池大小即客户端个数
[*]memcached.connectionPoolSize=50
[*]memcached.failureMode=true
[*]#server1
[*]memcached.server1.host=10.11.155.26
[*]memcached.server1.port=11211
[*]memcached.server1.weight=4
[*]#server2
[*]memcached.server2.host=10.11.155.41
[*]memcached.server2.port=11211
[*]memcached.server2.weight=3
[*]#server3
[*]memcached.server3.host=10.10.76.31
[*]memcached.server3.port=11211
[*]memcached.server3.weight=2
[*]#server4
[*]memcached.server4.host=10.10.76.35
[*]memcached.server4.port=11211
[*]memcached.server4.weight=1
[*]
XML配置文件：
Xml代码
[*]<?xml version="1.0" encoding="UTF-8"?>
[*]<beans
[*] xmlns="http://www.springframework.org/schema/beans"
[*] xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
[*] xmlns:context="http://www.springframework.org/schema/context"
[*] xmlns:p="http://www.springframework.org/schema/p"
[*] xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
[*] http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
[*] <!-- http://code.google.com/p/xmemcached/wiki/Spring_Integration -->
[*] <context:property-placeholder location="memcached.properties" />
[*] <bean
[*] id="memcachedClientBuilder"
[*] class="net.rubyeye.xmemcached.XMemcachedClientBuilder"
[*] p:connectionPoolSize="${memcached.connectionPoolSize}"
[*] p:failureMode="${memcached.failureMode}">
[*] <!-- XMemcachedClientBuilder have two arguments.First is server list,and
[*] second is weights array. -->
[*] <constructor-arg>
[*] <list>
[*] <bean class="java.net.InetSocketAddress">
[*] <constructor-arg>
[*] <value>${memcached.server1.host}</value>
[*] </constructor-arg>
[*] <constructor-arg>
[*] <value>${memcached.server1.port}</value>
[*] </constructor-arg>
[*] </bean>
[*] <bean class="java.net.InetSocketAddress">
[*] <constructor-arg>
[*] <value>${memcached.server2.host}</value>
[*] </constructor-arg>
[*] <constructor-arg>
[*] <value>${memcached.server2.port}</value>
[*] </constructor-arg>
[*] </bean>
[*] <bean class="java.net.InetSocketAddress">
[*] <constructor-arg>
[*] <value>${memcached.server3.host}</value>
[*] </constructor-arg>
[*] <constructor-arg>
[*] <value>${memcached.server3.port}</value>
[*] </constructor-arg>
[*] </bean>
[*] <bean class="java.net.InetSocketAddress">
[*] <constructor-arg>
[*] <value>${memcached.server4.host}</value>
[*] </constructor-arg>
[*] <constructor-arg>
[*] <value>${memcached.server4.port}</value>
[*] </constructor-arg>
[*] </bean>
[*] </list>
[*] </constructor-arg>
[*] <constructor-arg>
[*] <list>
[*] <value>${memcached.server1.weight}</value>
[*] <value>${memcached.server2.weight}</value>
[*] <value>${memcached.server3.weight}</value>
[*] <value>${memcached.server4.weight}</value>
[*] </list>
[*] </constructor-arg>
[*] <property name="commandFactory">
[*] <bean class="net.rubyeye.xmemcached.command.TextCommandFactory" />
[*] </property>
[*] <property name="sessionLocator">
[*] <bean class="net.rubyeye.xmemcached.impl.KetamaMemcachedSessionLocator" />
[*] </property>
[*] <property name="transcoder">
[*] <bean class="net.rubyeye.xmemcached.transcoders.SerializingTranscoder" />
[*] </property>
[*] </bean>
[*] <!-- Use factory bean to build memcached client -->
[*] <bean
[*] id="memcachedClient"
[*] factory-bean="memcachedClientBuilder"
[*] factory-method="build"
[*] destroy-method="shutdown" />
[*]</beans>
这里的memcachedClientBuilder节点完成MemcachedClientBuilder，然后通过memcachedClient节点配置factory-method，调用MemcachedClientBuilder的build()方法产生MemcachedClient，并配置destroy-method进行关闭。
不过我还是疑惑，这里的异常由谁来处理？Spring容器吗？ 或者需要另一个代理Bean包装一下？
有了Spring容器支持，我们不需要在代码中进行配置，也不需要重复调用build()跟shutdown()方法，这些操作交给Spring来完成。
代码如下：
Java代码
[*]import static junit.framework.Assert.*;
[*]
[*]import java.util.concurrent.TimeoutException;
[*]
[*]import net.rubyeye.xmemcached.MemcachedClient;
[*]import net.rubyeye.xmemcached.exception.MemcachedException;
[*]
[*]import org.junit.Before;
[*]import org.junit.Test;
[*]import org.springframework.context.ApplicationContext;
[*]import org.springframework.context.support.ClassPathXmlApplicationContext;
[*]
[*]public class MemcachedSpringTest {
[*]
[*] private ApplicationContext app;
[*] private MemcachedClient memcachedClient;
[*]
[*] @Before
[*] public void init() {
[*] app = new ClassPathXmlApplicationContext("applicationContext.xml");
[*] memcachedClient = (MemcachedClient) app.getBean("memcachedClient");
[*] }
[*]
[*] @Test
[*] public void test() {
[*] try {
[*] // 设置/获取
[*] memcachedClient.set("zlex", 36000, "set/get");
[*] assertEquals("set/get", memcachedClient.get("zlex"));
[*]
[*] // 替换
[*] memcachedClient.replace("zlex", 36000, "replace");
[*] assertEquals("replace", memcachedClient.get("zlex"));
[*]
[*] // 移除
[*] memcachedClient.delete("zlex");
[*] assertNull(memcachedClient.get("zlex"));
[*] } catch (TimeoutException e) {
[*] // TODO Auto-generated catch block
[*] e.printStackTrace();
[*] } catch (InterruptedException e) {
[*] // TODO Auto-generated catch block
[*] e.printStackTrace();
[*] } catch (MemcachedException e) {
[*] // TODO Auto-generated catch block
[*] e.printStackTrace();
[*] }
[*] }
[*]}
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