来讲讲：memcached 双机热备

小知识：Linux发展和成长过程始终依赖着五个重要支柱：UNIX操作系统、MINIX操作系统、GNU计划、POSIX标准和Internet网络。
1、需求背景
发明公司很多多少项目都用到memched。而且都是单点，memched办事器挂了就会影响营业，因而百度之，发明memched不成以集群，也没有看到有甚么高可用计划，可是发明了repcached（memched主从复制），分离LVS的NAT形式分歧端口转发完成memched双机HA，本文章纪录自己的部署历程，附属实战，没有笔墨性的申明，接待列位指导。
2、情况：
1、体系情况：

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• CentOSrelease6.4(Final)
  

2、收集情况

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• 调剂机（master）：
  
• vip：172.28.26.100
  
• vip1:172.28.16.100（lvs转发网关）
  
• eth1:172.28.26.101（内网）
  
• eth2:172.28.16.101（lvs转发网段）
  
• 调剂机（backup）：
  
• eth1:172.28.26.99（内网）
  
• eth2:172.28.16.99（lvs转发网段）
  
• memched备节点：
  
• eth1:172.28.26.102（内网）
  
• eth2:172.28.16.102（lvs转发网段）
  
• memched主节点：
  
• eth1:172.28.26.103（内网）
  
• eth2:172.28.16.103（lvs转发网段）
  

3、路由战略

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• 调剂机（master）：
  
• echo201eth1>>/etc/iproute2/rt_tables
  
• echodefaulttableeth1via172.28.26.1deveth1>/etc/sysconfig/network-scripts/route-eth1
  
• echofrom172.28.26.101/255.255.255.255tableeth1>/etc/sysconfig/network-scripts/rule-eth1
  
• echofrom172.28.26.100/255.255.255.255tableeth1>>/etc/sysconfig/network-scripts/rule-eth1
  
• echofrom172.28.16.101/32tableZW_LVS_LAN>/etc/sysconfig/network-scripts/rule-eth2
  
• memched节点1：
  
• echodefaulttableZW_LVS_LANvia172.28.16.100>/etc/sysconfig/network-scripts/route-eth2
  
• echofrom172.28.16.0/24tableZW_LVS_LAN>/etc/sysconfig/network-scripts/rule-eth2
  
• echo202ZW_LVS_LAN>>/etc/iproute2/rt_tables
  
• memched节点2：
  
• echodefaulttableZW_LVS_LANvia172.28.16.100>/etc/sysconfig/network-scripts/route-eth2
  
• echofrom172.28.16.0/24tableZW_LVS_LAN>/etc/sysconfig/network-scripts/rule-eth2
  
• echo202ZW_LVS_LAN>>/etc/iproute2/rt_tables
  

4、内核参数

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• fs.file-max=1000000
  
• kernel.core_uses_pid=1
  
• kernel.msgmax=1048560
  
• kernel.msgmnb=1073741824
  
• kernel.shmall=4294967296
  
• kernel.shmmax=68719476736
  
• kernel.sysrq=0
  
• net.core.netdev_max_backlog=1048576
  
• net.core.rmem_default=2097152
  
• net.core.rmem_max=16777216
  
• net.core.somaxconn=1048576
  
• net.core.wmem_default=2097152
  
• net.core.wmem_max=16777216
  
• net.ipv4.conf.default.accept_source_route=0
  
• net.ipv4.conf.default.rp_filter=1
  
• net.ipv4.ip_forward=1
  
• net.ipv4.ip_local_port_range=102465000
  
• net.ipv4.neigh.default.gc_thresh1=10240
  
• net.ipv4.neigh.default.gc_thresh2=40960
  
• net.ipv4.neigh.default.gc_thresh3=81920
  
• net.ipv4.tcp_fin_timeout=1
  
• net.ipv4.tcp_keepalive_intvl=15
  
• net.ipv4.tcp_keepalive_probes=5
  
• net.ipv4.tcp_keepalive_time=30
  
• net.ipv4.tcp_max_orphans=3276800
  
• net.ipv4.tcp_max_syn_backlog=1048576
  
• net.ipv4.tcp_max_tw_buckets=50000
  
• net.ipv4.tcp_mem=94500000915000000927000000
  
• net.ipv4.tcp_orphan_retries=3
  
• net.ipv4.tcp_reordering=5
  
• net.ipv4.tcp_retrans_collapse=0
  
• net.ipv4.tcp_retries2=5
  
• net.ipv4.tcp_rmem=4096873804194304
  
• net.ipv4.tcp_sack=1
  
• net.ipv4.tcp_synack_retries=1
  
• net.ipv4.tcp_syncookies=0
  
• net.ipv4.tcp_syn_retries=1
  
• net.ipv4.tcp_timestamps=1
  
• net.ipv4.tcp_tw_recycle=1
  
• net.ipv4.tcp_tw_reuse=1
  
• net.ipv4.tcp_window_scaling=1
  
• net.ipv4.tcp_wmem=4096163844194304
  
• net.ipv6.conf.all.disable_ipv6=1
  
• net.ipv6.conf.default.disable_ipv6=1
  
• net.ipv4.conf.eth0.rp_filter=1#memched节点不必要
  
• net.ipv4.conf.eth1.rp_filter=1#memched节点不必要
  
• net.ipv4.conf.eth2.rp_filter=1#memched节点不必要
  
• net.ipv4.conf.all.rp_filter=0#memched节点不必要
  

3、办事安装
1、调剂机（master、backup）

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• yum-yinstallipvsadmkeepalivedsendmail
  

2、memched节点1、memched节点2

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• wgethttp://memcached.googlecode.com/files/memcached-1.4.15.tar.gz
  
• wgethttp://www.monkey.org/~provos/libevent-1.4.13-stable.tar.gz
  
• wgethttp://downloads.sourceforge.net/repcached/memcached-1.2.8-repcached-2.2.tar.gz
  

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• tar-zxvflibevent-1.4.13-stable.tar.gz
  
• cdlibevent-1.4.13-stable
  
• ./configure--prefix=/usr/local
  
• make
  
• makeinstall
  
• 
  
• tar-zxvfmemcached-1.4.15.tar.gz
  
• cdmemcached-1.4.15
  
• ./configure--with-libevent=/usr/local
  
• make
  
• makeinstall
  
• 
  
• tar-zxvfmemcached-1.2.8-repcached-2.2.tar.gz
  
• cdmemcached-1.2.8-repcached-2.2
  
• ./configure--enable-replication
  
• make
  
• makeinstall
  

4、keepalived设置（master、backup）
[root@LVS1keepalived]#cat/etc/keepalived/gobal_module
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其实当你安装了一个完整的Linux系统后其中已经包含了一个强大的帮助，只是可能你还没有发现和使用它们的技巧。

请问谁有Linux的学习心得的吗？简单的说说？

熟悉并掌握安装Linux，安装是学习的前提。目前较常见的安装方法有二种：

写学习日记，这是学习历程的见证，同时我坚持认为是增强学习信念的法宝。

老实说，第一个程序是在C中编译好的，调试好了才在Linux下运行，感觉用vi比较麻烦，因为有错了不能调试，只是提示错误。

任何一个叫做操作系统的东西都是这样子构成的：内核+用户界面+一般应用程序。

Linux只是个内核!这点很重要，你必须理解这一点。只有一个内核是不能构成一个操作系统的。

编程学习及开发，Linux是免费，开源的操作系统，并且可开发工具相当多，如果您支持自由软件，一定要同广大热爱自由软件人士一同为其不懈努力。