HAproxy代理

标签：haproxy

backend mywebsrvs
balance roundrobin
server srv1 172.18.62.60:80 check
server srv2 172.18.62.63:80 check
log 127.0.0.1 local5
vim /etc/rsyslog.conf 设置日志
$ModLoad imudp 去掉注释
$UDPServerRun 514
local5.* /var/log/haproxy.log
systemctl restart haproxy
systemctl restart rsyslog
tail /var/log/haproxy.log -f

（2）B机器，ip为172.18.62.60
echo RS1 > /var/www/html/index.html
systemctl start httpd
（3）C机器，ip为172.18.62.63
systemctl start httpd
echo RS2 > /var/www/html/index.html
（4）D机器，ip为172.18.62.50
for i in {1..1000};do sleep 0.5;curl 172.18.62.61;done
当将rs关掉一个时，立马切换到另一个rs调度，速度很快
10、docker必须工作在前台
HAProxy:

LB Cluster:
    四层：
        lvs, nginx(stream)，haproxy(mode tcp)
    七层：
        http: nginx(http, ngx_http_upstream_module), haproxy(mode http), httpd, ats, 

perlbal, pound...

HAProxy：
    http://www.haproxy.org
    http://www.haproxy.com 

    文档：
        http://cbonte.github.io/haproxy-dconv/

    HAProxy is a TCP/HTTP reverse proxy which is particularly suited for high availability      

environments. Indeed, it can:
: - route HTTP requests depending on statically assigned cookies
: - spread load among several servers while assuring server persistence
: through the use of HTTP cookies
: - switch to backup servers in the event a main server fails
: - accept connections to special ports dedicated to service monitoring
: - stop accepting connections without breaking existing ones
: - add, modify, and delete HTTP headers in both directions
: - block requests matching particular patterns
: - report detailed status to authenticated users from a URI intercepted by the
application

    版本：1.4, 1.5, 1.6, 1.7

    程序环境：
        主程序：/usr/sbin/haproxy
        主配置文件：/etc/haproxy/haproxy.cfg
        Unit file：/usr/lib/systemd/system/haproxy.service

    配置段：
        global：全局配置段
            进程及安全配置相关的参数
            性能调整相关参数
            Debug参数
            用户列表
            peers
        proxies：代理配置段
            defaults：为frontend, listen, backend提供默认配置；
            fronted：前端，相当于nginx, server {}
            backend：后端，相当于nginx, upstream {}
            listen：同时拥前端和后端

        简单的配置示例：
            frontend web
                bind *:80
                default_backend     websrvs

            backend websrvs
                balance roundrobin
                server srv1 172.16.100.6:80 check
                server srv2 172.16.100.7:80 check               

        global配置参数：
            进程及安全管理：chroot, daemon，user, group, uid, gid

                log：定义全局的syslog服务器；最多可以定义两个路径；
                    log <address> [len <length>] <facility> [max level [min level]]

                nbproc <number>：要启动的haproxy的进程数量；
                ulimit-n <number>：每个haproxy进程可打开的最大文件数；每个套接
字都需要一个文件描述符，即一个被打开的文件以跟踪进程状态；这里
haproxy可以实现自动调整；
                ulimit：用来限制核心资源的使用
            性能调整：
                maxconn <number>：设定每个haproxy进程所能接受的最大并发连接
数；Sets the maximum per-process number of concurrent connections 
to <number>. 
                                总体的并发连接数：nbproc * maxconn
                maxconnrate <number>：Sets the maximum per-process number of 
connections per second to <number>. 每个进程每秒种所能创建的最大
连接数量；#防止一瞬间大量连接请求，创建文件，内存速度跟不上，
导致服务器压力很大；
                maxse***ate <number>：
                maxsslconn <number>: Sets the maximum per-process number of 
                    concurrent SSL connections to <number>.
                                设定每个haproxy进程所能接受的ssl的最大并发连接数；
                spread-checks <0..50, in percent>   分散连接，提前或延迟在0到50%之
间

        代理配置段：
            - defaults <name>
            - frontend <name>
            - backend  <name>
            - listen   <name>

            A "frontend" section describes a set of listening sockets accepting client 

connections. #用于承载前端的连接
A "backend" section describes a set of servers to which the proxy will
connect to forward incoming connections. #用于承载后端的连接
A "listen" section defines a complete proxy with its frontend and backend
parts combined in one section. It is generally useful for TCP-only traffic. 对
应配置段的标识符；

            All proxy names must be formed from upper and lower case letters, digits, ‘-
‘ (dash), ‘_‘ (underscore) , ‘.‘ (dot) and ‘:‘ (colon). 区分字符大小写；

            配置参数：

            bind：Define one or several listening addresses and/or ports in a frontend.
                bind [<address>]:<port_range> [, ...] [param*]

                listen http_proxy
                    bind :80,:443
                    bind 10.0.0.1:10080,10.0.0.1:10443
                    bind /var/run/ssl-frontend.sock user root mode 600 accept-proxy
                    套接字：ipvs套接字和socket套接字

socket套接字是基于ipc通信的，只能是在同一个机器上
bind只用于前端frontend和listen，可以查文档得知：
http://cbonte.github.io/haproxy-dconv/1.5/configuration.html#4.1
balance：后端服务器组内的服务器调度算法
balance <algorithm> [ <arguments> ]
balance url_param <param> [check_post]
查文档可知可以设置defaluts、backend和listen
算法：
roundrobin：Each server is used in turns, according to their
weights.
server options： weight #
动态算法：支持权重的运行时调整，而不会打乱整个权重分
布，支持慢启动；每个后端中最多支持4095个server；即不
必重启服务，给新机器慢慢加连接数以达到指定权重；
static-rr：
静态算法：不支持权重的运行时调整及慢启动；后端主机数
量无上限；
leastconn：
推荐使用在具有较长会话的场景中，例如MySQL、LDAP
等；
算法是动态的还是静态的取决于hash_type的值
first：
根据服务器在列表中的位置，自上而下进行调度；前面服务
器的连接数达到上限，新请求才会分配给下一台服务；
source：源地址hash；
除权取余法：
一致性哈希：
基于cookie的调度比较好，但是需要用到7层调度，不用，
因为后台服务器坏了就没法了；
会话不绑定应该采用：
会话粘性，如cookie
会话复制集群：涉及到会话在后端服务器间的复制
session server：集中负责会话保存的服务器
uri：
对URI的左半部分做hash计算，并由服务器总权重相除以后
派发至某挑出的服务器；
<scheme>://<user>:<password>@<host>:
<port>/<path>;<params>?<query>#<frag>
左半部分：/<path>;<params>
整个uri：/<path>;<params>?<query>#<frag>

                    url_param：对用户请求的uri听<params>部分中的参数的值作

hash计算，并由服务器总权重相除以后派发至某挑出的服务器；
通常用于追踪用户，以确保来自同一个用户的请求始终发往同一
个Backend Server；

                    hdr(<name>)：对于每个http请求，此处由<name>指定的http首部

将会被取出做hash计算； 并由服务器总权重相除以后派发至某
挑出的服务器；没有有效值的会被轮询调度；
hdr(Cookie) 常用，调用灵活细致；每个浏览器的cookie都
是不同的，甚至同一个浏览器的两个进程的cookie也是
不同的；
rdp-cookie
rdp-cookie(<name>)

                hash-type：哈希算法
                    hash-type <method> <function> <modifier>
                        map-based：除权取余法，哈希数据结构是静态的数组；
                        consistent：一致性哈希，哈希数据结构是一个树；

                    <function> is the hash function to be used : 哈希函数
                        sdbm
                        djb2
                        wt6

                default_backend <backend>
                    设定默认的backend，用于frontend中；
                default-server [param*]
                    为backend中的各server设定默认选项；
                server <name> <address>[:[port]] [param*]
                    定义后端主机的各服务器及其选项；
                     server <name> <address>[:port] [settings ...]
                    default-server [settings ...]
                    <name>：服务器在haproxy上的内部名称；出现在日志及警告信

息；
<address>：服务器地址，支持使用主机名；
[:[port]]：端口映射；省略时，表示同bind中绑定的端口；
[param*]：参数
maxconn <maxconn>：当前server的最大并发连接数；
backlog <backlog>：当前server的连接数达到上限后的后援
队列长度；要根据压测进行设置
backup：设定当前server为备用服务器；
check：对当前server做健康状态检测；
addr ：检测时使用的IP地址；可以对机器的其他ip检测
port ：针对此端口进行检测；
inter <delay>：连续两次检测之间的时间间隔，默认为
2000ms;
rise <count>：连续多少次检测结果为“成功”才标记服务
器为可用；默认为2；
fall <count>：连续多少次检测结果为“失败”才标记服务
器为不可用；默认为3；
健康性检测有3种：网络层检测、传输层检测和应用层检
测；网络层检测只是ping下，准确度不高；传输层检测
是对端口进行检测，保证了服务还在运行；而应用层检
测则很准确，都能访问页面等资源了；
注意：httpchk，"smtpchk", "mysql-check", "pgsql-
check" and "ssl-hello-chk" 用于定义应用层检测方法；

                        cookie <value>：为当前server指定其cookie值，用于实现基

于cookie的会话黏性；
disabled：标记为不可用；
on-error <mode>：后端服务故障时的行动策略；

• fastinter: force fastinter 快速再次测试
• fail-check: simulate a failed check, also forces fastinter (default)
• sudden-death: simulate a pre-fatal failed health check, one more failed
  check will mark a server down, forces fastinter

• mark-down: mark the server immediately down and force fastinter
  redir <prefix>：将发往此server的所有GET和HEAD类的请求重定向至指定的URL；
  weight <weight>：权重，默认为1;

                  OK --> PROBLEM
                      OK --> PROBLEM --> PROBLEM --> PROBLEM
                  PROBLEM --> OK
  
              统计接口启用相关的参数：
                  stats enable
                      启用统计页；基于默认的参数启用stats page；

• stats uri : /haproxy?stats
• stats realm : "HAProxy Statistics"
• stats auth : no authentication

• stats scope : no restriction

                  stats auth <user>:<passwd>
                      认证时的账号和密码，可使用多次；
  
                  stats realm <realm>
                      认证时的realm；
  
                  stats uri <prefix>
                      自定义stats page uri
  
                  stats refresh <delay>
                      设定自动刷新时间间隔；
  
                  stats admin { if | unless } <cond>
                      启用stats page中的管理功能
  
                  配置示例：
                      listen stats
                          bind :9099
                          stats enable
                          stats realm HAPorxy\ Stats\ Page
                          stats auth admin:admin
                          stats admin if TRUE     
  
              maxconn <conns>：为指定的frontend定义其最大并发连接数；默认为2000；
                  Fix the maximum number of concurrent connections on a frontend.  
  
              mode { tcp|http|health }
                  定义haproxy的工作模式；
                      tcp：基于layer4实现代理；可代理mysql, pgsql, ssh, ssl等协议；
                      http：仅当代理的协议为http时使用；
                      health：工作为健康状态检查的响应模式，当连接请求到达时回应“OK”后即断开连接；
  
                  示例：
                      listen ssh
                          bind :22022
                          balance leastconn
                          mode tcp
                          server sshsrv1 172.16.100.6:22 check
                          server sshsrv2 172.16.100.7:22 check        
  
              cookie <name> [ rewrite | insert | prefix ] [ indirect ] [ nocache ]  [ postonly ] [ preserve ] [ httponly ] [ secure ]  [ domain <domain> ]* [ maxidle <idle> ] [ maxlife <life> ]
                  <name>：is the name of the cookie which will be monitored, modified or inserted in order to bring persistence.
                      rewirte：重写；
                      insert：插入；
                      prefix：前缀；
  
                  基于cookie的session sticky的实现：
                      backend websrvs
                          cookie WEBSRV insert nocache indirect
                          server srv1 172.16.100.6:80 weight 2 check rise 1 fall 2 maxconn 3000 cookie srv1
                          server srv2 172.16.100.7:80 weight 1 check rise 1 fall 2 maxconn 3000 cookie srv2               
                          注意：cookie实现会话绑定，但是curl默认是不使用cookie的；
  
              option forwardfor [ except <network> ] [ header <name> ] [ if-none ]
                  Enable insertion of the X-Forwarded-For header to requests sent to servers
  
                  在由haproxy发往后端主机的请求报文中添加“X-Forwarded-For”首部，其值前端客户端的地址；用于向后端主发送真实的客户端IP；
                      [ except <network> ]：请求报请来自此处指定的网络时不予添加此首部；
                      [ header <name> ]：使用自定义的首部名称，而非“X-Forwarded-For”；
                  例子：

  vim haproxy.cfg 前端配置
  defaluts
  option forwardfor except 127.0.0.0/8
  vim /etc/httpd/conf/httpd.conf rs配置
  LogFormat "%{X-Forwarded-For}i %l %u %t \"%r\" %>s %b
  \"%{Referer}i\" \"%{User-Agent}i\"" combined
  systemctl reload httpd
  tail /var/log/httpd/access_log 查看日志可以看到真实客户端ip

              errorfile <code> <file>
                  Return a file contents instead of errors generated by HAProxy
  
                  <code>：is the HTTP status code. Currently, HAProxy is capable of  generating codes 200, 400, 403, 408, 500, 502, 503, and 504.

  没有404的原因：是rs生成的，没法子改变；
  <file>：designates a file containing the full HTTP response.

                  示例：
                      errorfile 400 /etc/haproxy/errorfiles/400badreq.http
                      errorfile 408 /dev/null  # workaround Chrome pre-connect bug
                      errorfile 403 /etc/haproxy/errorfiles/403forbid.http
                      errorfile 503 /etc/haproxy/errorfiles/503sorry.http 
  
              errorloc <code> <url>
              errorloc302 <code> <url>
  
                  errorfile 403 http://www.magedu.com/error_pages/403.html
  
              reqadd  <string> [{if | unless} <cond>]
                  Add a header at the end of the HTTP request
  
              rspadd <string> [{if | unless} <cond>]
                  Add a header at the end of the HTTP response
  
                  rspadd X-Via:\ HAPorxy
                  对由haproxy转发的响应报文首部添加字段，不能直接添加到响应

  报文，因为响应报文是由rs生成的；
  reqdel <search> [{if | unless} <cond>]
  reqidel <search> [{if | unless} <cond>] (ignore case)
  Delete all headers matching a regular expression in an HTTP request
  删除忽略字符大小写的某个首部字段
  rspdel <search> [{if | unless} <cond>]
  rspidel <search> [{if | unless} <cond>] (ignore case)
  Delete all headers matching a regular expression in an HTTP response

                  rspidel  Server.*
  
          日志系统：           
              log：
                  log global
                  log <address> [len <length>] <facility> [<level> [<minlevel>]]
                  no log
  
                  注意：
                      默认发往本机的日志服务器；
                          (1) local2.*      /var/log/local2.log 
                          (2) $ModLoad imudp
                              $UDPServerRun 514
  
              log-format <string>：
                  课外实践：参考文档实现combined格式的记录
  
              capture cookie <name> len <length>
                  Capture and log a cookie in the request and in the response.
  
              capture request header <name> len <length>
                  Capture and log the last occurrence of the specified request header.
  
                  capture request header X-Forwarded-For len 15
  
              capture response header <name> len <length>
                  Capture and log the last occurrence of the specified response header.
  
                  capture response header Content-length len 9
                  capture response header Location len 15         
  
          为指定的MIME类型启用压缩传输功能
              compression algo <algorithm> ...：启用http协议的压缩机制，指明压缩算法gzip, deflate；
              compression type <mime type> ...：指明压缩的MIME类型；常适用于压缩的类型为文本类型；
  
          对后端服务器做http协议的健康状态检测：
              option httpchk  7层检测
              option httpchk <uri>
              option httpchk <method> <uri>
              option httpchk <method> <uri> <version>     
                  定义基于http协议的7层健康状态检测机制；
  
              http-check expect [!] <match> <pattern>
                  Make HTTP health checks consider response contents or specific status codes.
  
          连接超时时长：     
              timeout client <timeout>
                  Set the maximum inactivity time on the client side. 默认单位是毫秒; 
  
              timeout server <timeout>
                  Set the maximum inactivity time on the server side.
  
              timeout http-keep-alive <timeout>
                  持久连接的持久时长；
  
              timeout http-request <timeout>
                  Set the maximum allowed time to wait for a complete HTTP request
  
              timeout connect <timeout>
                  Set the maximum time to wait for a connection attempt to a server to succeed.
  
              timeout client-fin <timeout>
                  Set the inactivity timeout on the client side for half-closed connections.
  
              timeout server-fin <timeout>
                  Set the inactivity timeout on the server side for half-closed connections.
  
              use_backend <backend> [{if | unless} <condition>]
                  Switch to a specific backend if/unless an ACL-based condition is matched.
                  当符合指定的条件时使用特定的backend；
  
              block { if | unless } <condition>
                  Block a layer 7 request if/unless a condition is matched
  
                  acl invalid_src src 172.16.200.2
                  block if invalid_src
                  errorfile 403 /etc/fstab    
  
              http-request { allow | deny } [ { if | unless } <condition> ]
                  Access control for Layer 7 requests
  
              tcp-request connection {accept|reject}  [{if | unless} <condition>]
                  Perform an action on an incoming connection depending on a layer 4 condition
  
                  示例：
                      listen ssh
                          bind :22022
                          balance leastconn
                          acl invalid_src src 172.16.200.2
                          tcp-request connection reject if invalid_src
                          mode tcp
                          server sshsrv1 172.16.100.6:22 check
                          server sshsrv2 172.16.100.7:22 check backup         

  acl：
  The use of Access Control Lists (ACL) provides a flexible solution to perform content switching and generally to take decisions based on content extracted from the request, the response or any environmental status.

  acl <aclname> <criterion> [flags] [operator] [<value>] ...
      <aclname>：ACL names must be formed from upper and lower case letters, digits, ‘-‘ (dash), ‘_‘ (underscore) , ‘.‘ (dot) and ‘:‘ (colon).ACL names are case-sensitive.
  
      <value>的类型：
          - boolean
          - integer or integer range
          - IP address / network
          - string (exact, substring, suffix, prefix, subdir, domain)
          - regular expression
          - hex block
  
      <flags>
          -i : ignore case during matching of all subsequent patterns.
          -m : use a specific pattern matching method
          -n : forbid the DNS resolutions
          -u : force the unique id of the ACL
          -- : force end of flags. Useful when a string looks like one of the flags.  
  
       [operator] 
          匹配整数值：eq、ge、gt、le、lt
  
          匹配字符串：
              - exact match     (-m str) : the extracted string must exactly match the patterns ;
              - substring match (-m sub) : the patterns are looked up inside the extracted string, and the ACL matches if any of them is found inside ;
              - prefix match    (-m beg) : the patterns are compared with the beginning of the extracted string, and the ACL matches if any of them matches.
              - suffix match    (-m end) : the patterns are compared with the end of the extracted string, and the ACL matches if any of them matches.
              - subdir match    (-m dir) : the patterns are looked up inside the extracted string, delimited with slashes ("/"), and the ACL matches if any of them matches.
              - domain match    (-m dom) : the patterns are looked up inside the extracted string, delimited with dots ("."), and the ACL matches if any of them matches. 
  
      acl作为条件时的逻辑关系：
          - AND (implicit)
          - OR  (explicit with the "or" keyword or the "||" operator)
          - Negation with the exclamation mark ("!")
  
              if invalid_src invalid_port
              if invalid_src || invalid_port
              if ! invalid_src invalid_port   非只作用于第一个条件
  
      <criterion> ：
          dst : ip
          dst_port : integer
          src : ip
          src_port : integer
  
              acl invalid_src  src  172.16.200.2
  
          path : string
              This extracts the request‘s URL path, which starts at the first slash and ends before the question mark (without the host part).
                  /path;<params>
  
              path     : exact string match
              path_beg : prefix match
              path_dir : subdir match
              path_dom : domain match
              path_end : suffix match
              path_len : length match
              path_reg : regex match
              path_sub : substring match  
      例子： 
                  path_beg /images/
                  path_end .jpg .jpeg .png .gif
                  path_reg ^/images.*\.jpeg$
                  path_sub image 
                  path_dir jpegs      2个斜线之间的精确匹配
                  path_dom ilinux 2个.之间的精确匹配
                      /images/jpegs/20180312/logo.jpg
  
          url : string
              This extracts the request‘s URL as presented in the request. A typical use is with prefetch-capable caches, and with portals which need to aggregate multiple information from databases and keep them in caches.
  
              url     : exact string match
              url_beg : prefix match
              url_dir : subdir match
              url_dom : domain match
              url_end : suffix match
              url_len : length match
              url_reg : regex match
              url_sub : substring match
  
          req.hdr([<name>[,<occ>]]) : string
              This extracts the last occurrence of header <name> in an HTTP request.
  
              hdr([<name>[,<occ>]])     : exact string match
              hdr_beg([<name>[,<occ>]]) : prefix match
              hdr_dir([<name>[,<occ>]]) : subdir match
              hdr_dom([<name>[,<occ>]]) : domain match
              hdr_end([<name>[,<occ>]]) : suffix match
              hdr_len([<name>[,<occ>]]) : length match
              hdr_reg([<name>[,<occ>]]) : regex match
              hdr_sub([<name>[,<occ>]]) : substring match                 
  
              示例：
                  acl bad_curl hdr_sub(User-Agent) -i curl
                  block if bad_curl                   
  
          status : integer
              Returns an integer containing the HTTP status code in the HTTP response.
  
      Pre-defined ACLs    预定义，内建的acl
          ACL name    Equivalent to   Usage
          FALSE   always_false    never match
          HTTP    req_proto_http  match if protocol is valid HTTP
          HTTP_1.0    req_ver 1.0 match HTTP version 1.0
          HTTP_1.1    req_ver 1.1 match HTTP version 1.1
          HTTP_CONTENT    hdr_val(content-length) gt 0    match an existing content-length
          HTTP_URL_ABS    url_reg ^[^/:]*://  match absolute URL with scheme
          HTTP_URL_SLASH  url_beg /   match URL beginning with "/"
          HTTP_URL_STAR   url *   match URL equal to "*"
          LOCALHOST   src 127.0.0.1/8 match connection from local host
          METH_CONNECT    method CONNECT  match HTTP CONNECT method
          METH_GET    method GET HEAD match HTTP GET or HEAD method
          METH_HEAD   method HEAD match HTTP HEAD method
          METH_OPTIONS    method OPTIONS  match HTTP OPTIONS method
          METH_POST   method POST match HTTP POST method
          METH_TRACE  method TRACE    match HTTP TRACE method
          RDP_COOKIE  req_rdp_cookie_cnt gt 0 match presence of an RDP cookie
          REQ_CONTENT req_len gt 0    match data in the request buffer
          TRUE    always_true always match
          WAIT_END    wait_end    wait for end of content analysis                

  HAProxy：global, proxies（fronted, backend, listen, defaults）
  balance：
  roundrobin, static-rr 后端web服务器都是静态资源
  leastconn mysql调度要用到
  first
  source
  hdr(<name>)
  uri (hash-type) 缓存调度用到
  url_param

  Nginx调度算法：ip_hash, hash, leastconn, 
  lvs调度算法：
      rr/wrr/sh/dh, lc/wlc/sed/nq/lblc/lblcr
  
  基于ACL的动静分离示例：
      frontend  web *:80
          acl url_static       path_beg       -i  /static /images /javascript /stylesheets
          acl url_static       path_end       -i  .jpg .gif .png .css .js .html .txt .htm
  
          use_backend staticsrvs          if url_static
          default_backend             appsrvs
  
      backend staticsrvs
          balance     roundrobin
          server      stcsrv1 172.16.100.6:80 check
  
      backend appsrvs
          balance     roundrobin
          server  app1 172.16.100.7:80 check
          server  app1 172.16.100.7:8080 check
  
      listen stats
          bind :9091
          stats enable
          stats auth admin:admin
          stats admin if TRUE     

  配置HAProxy支持https协议：
  1 支持ssl会话；
  bind *:443 ssl crt /PATH/TO/SOME_PEM_FILE

      crt后的证书文件要求PEM格式，且同时包含证书和与之匹配的所有私钥；
  
          cat  demo.crt demo.key > demo.pem 
  
  2 把80端口的请求重向定443；
      bind *:80
      redirect scheme https if !{ ssl_fc }
  
      另一种配置：对非ssl的任何url的访问统统定向至https主机的主页；
      redirect location https://172.16.0.67/ if !{ ssl_fc }
  
  3 如何向后端传递用户请求的协议和端口
      http_request set-header X-Forwarded-Port %[dst_port]
      http_request add-header X-Forwared-Proto https if { ssl_fc }

  配置时常用的功能：
  http --> https

  mode http
  压缩、条件式转发、算法、stats page、自定义错误页、访问控制、日志功能
  最大并发连接；
      global, defaults, frontend, listen, server 
  基于cookie的session粘滞
  后端主机的健康状态检测
  请求和响应报文首部的操纵
  
  实践（博客）作业：
      http:
          (1) 动静分离部署wordpress，动静都要能实现负载均衡，要注意会话的问题；
          (2) 在haproxy和后端主机之间添加varnish进行缓存；
          (3) 给出设计拓扑，写成博客；
  
          (4) haproxy的设定要求：
              (a) stats page，要求仅能通过本地访问使用管理接口； 
              (b) 动静分离；
              (c) 分别考虑不同的服务器组的调度算法；
              (4) 压缩合适的内容类型；

HAproxy代理

标签：haproxy

原文地址：http://blog.51cto.com/angwoyufengtian/2126391