【Mycat】Mycat讀寫分離與負載均衡2

小亮520cl發表於2017-04-17
負載
上篇文章我們學習了schemal配置檔案的基本資訊，這節我們來學習讀寫分離與負載均衡
先看一下balance 屬性

  1. 負載均衡型別，目前的取值有3種：
    1. balance="0",     不開啟讀寫分離機制，所有讀操作都傳送到當前可用的writeHost上。

    2. balance="1"，全部的readHost與stand by writeHost參與select語句的負載均衡，簡單的說，當雙主雙從模式(M1->S1，M2->S2，並且M1與 M2互為主備)，正常情況下，M2,S1,S2都參與select語句的負載均衡。

    3. balance="2"，所有讀操作都隨機的在writeHost、readhost上分發。

    4. balance="3"，所有讀請求隨機的分發到wiriterHost對應的readhost執行，writerHost不負擔讀壓力，注意balance=3只在1.4及其以後版本有，1.3沒有。



writeType屬性
  1. 負載均衡型別，目前的取值有3種：
  2. 1. writeType="0", 所有寫操作傳送到配置的第一個writeHost，第一個掛了切到還生存的第二個writeHost，重新啟動後已切換後的為準，切換記錄在配置檔案中:dnindex.properties .
  3. 2. writeType="1"，所有寫操作都隨機的傳送到配置的writeHost。 
  4. 3. writeType="2"，沒實現。





所以我們根據第二種方式做負載均衡
  1. <dataNode name="dn1" dataHost="localhost1" database="examdb" />
  2.         <dataNode name="dn2" dataHost="localhost2" database="examdb" />
  3.         <dataNode name="dn3" dataHost="localhost3" database="examdb" />



  7.         <dataHost name="localhost1" maxCon="1000" minCon="10" balance="2"
  8.                           writeType="0" dbType="mysql" dbDriver="native" switchType="1" slaveThreshold="100">
  9.                 <heartbeat>select user()</heartbeat>
  10.                 <!-- can have multi write hosts -->
  11.                 <writeHost host="hostM1" url="192.168.6.121:3306" user="root"
  12.                                    password="ESBecs00">
  13.                         <!-- can have multi read hosts -->
  14.                 </writeHost>
  15.                 

  17.                 <writeHost host="hostS1" url="192.168.6.121:3307" user="root"
  18.                                    password="ESBecs00">
  19.                         <!-- can have multi read hosts -->
  20.                 </writeHost>
  21.         </dataHost>
  22.         

  24.         <dataHost name="localhost2" maxCon="1000" minCon="10" balance="2"
  25.                           writeType="0" dbType="mysql" dbDriver="native" switchType="1" slaveThreshold="100">
  26.                 <heartbeat>select user()</heartbeat>
  27.                 <!-- can have multi write hosts -->
  28.                 <writeHost host="hostM1" url="192.168.6.120:3306" user="root"
  29.                                    password="ESBecs00">
  30.                         <!-- can have multi read hosts -->
  31.                 </writeHost>
  32.                 
  33.                 <writeHost host="hostS1" url="192.168.6.120:3307" user="root"
  34.                                    password="ESBecs00">
  35.                         <!-- can have multi read hosts -->
  36.                 </writeHost>

  38.         </dataHost>

  40.         <dataHost name="localhost3" maxCon="1000" minCon="10" balance="2"
  41.                           writeType="0" dbType="mysql" dbDriver="native" switchType="1" slaveThreshold="100">
  42.                 <heartbeat>select user()</heartbeat>
  43.                 <!-- can have multi write hosts -->
  44.                 <writeHost host="hostM1" url="192.168.6.119:3306" user="root"
  45.                                    password="ESBecs00">
  46.                         <!-- can have multi read hosts -->
  47.                 </writeHost>
  48.                 
  49.                 <writeHost host="hostM1" url="192.168.6.119:3307" user="root"
  50.                                    password="ESBecs00">
  51.                         <!-- can have multi read hosts -->
  52.                 </writeHost>

  54.         </dataHost>
測試
  1.   #!/usr/bin/bash
    for((i=1;i<=1000;i++))
    do
    mysql -uroot -p123456 -P8066 -h127.0.0.1  -e "select name from company" TESTDB;
    done
       
  2. root@localhost logs]# sort test-blance.log |more |uniq -c 
  3.      30 this is 119
         17 this is 119:3307
         28 this is 120
         23 this is 120:3307
         36 this is 121
         26 this is 121:3307


如上：6臺機器全部都有讀到，讀負載均衡成功

來自 “ ITPUB部落格 ” ，連結：http://blog.itpub.net/29096438/viewspace-2137405/，如需轉載，請註明出處，否則將追究法律責任。

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