1.下載mycat:
https://raw.githubusercontent.com/MyCATApache/Mycat-download/master/1.5-RELEASE/Mycat-server-1.5-RELEASE-20160301083012-linux.tar.gz
2.安裝mycat:
tar -zxvf Mycat-server-1.5-GA-20160225120029-linux.tar.gz
mv mycat /srv/mycat-1.5
ln -s mycat-1.5 mycat
3.配置java環境變量:
which java
在bin/startup_nowrap.sh文件中找到noJavaHome=false行下並增加如下內容:
JAVA_HOME=Java_home的實際路徑
4.配置conf/schema.xml文件:
該文件主要配置讀寫分離數據庫的連接地址信息,具體如下:
root@ebj-rd-02:/srv/mycat/conf# cat schema.xml
<?xml version="1.0"?>
<!DOCTYPE mycat:schema SYSTEM "schema.dtd">
<mycat:schema xmlns:mycat="http://org.opencloudb/">
<schema name="mydb" checkSQLschema="false" sqlMaxLimit="100" dataNode="dn1"/>
<dataNode name="dn1" dataHost="localhost1" database="test" />
<dataHost name="localhost1" maxCon="1000" minCon="50" balance="1"
writeType="0" dbType="mysql" dbDriver="native" switchType="-1" >
<heartbeat>select user()</heartbeat>
<writeHost host="host_3320" url="127.0.0.1:3320" user="root" password="password">
<readHost host="host_3321" url="127.0.0.1:3321" user="root" password="password"/>
<readHost host="host_3322" url="127.0.0.1:3322" user="root" password="password"/>
</writeHost>
</dataHost>
</mycat:schema>
文件終於參數說明:
這裏mydb 就是我們對外聲稱的我們有數據庫的名稱 必須和server.xml中的用戶指定的數據庫名稱一致
添加一個dataNode="dn1" 是指定了我們這個庫只在dn1上.沒有進行分庫
sqlMaxLimit表示sql語句最大返回的結果集的大小;
writeHost和readHost配置的是實際的讀數據庫和寫數據庫的IP地址端口,用戶名及密碼;
balance 屬性負載均衡類型,目前的取值有 4 種:
1. balance="0", 不開啓讀寫分離機制,所有讀操作都發送到當前可用的 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 互爲主備),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,目前的取值有 3 種:
1. writeType="0", 所有寫操作發送到配置的第一個 writeHost,第一個掛了切到還生存的第二個
writeHost,重新啓動後已切換後的爲準,切換記錄在配置文件中:dnindex.properties .
2. writeType="1",所有寫操作都隨機的發送到配置的 writeHost。
3. writeType="2",沒實現。
switchType 屬性
- -1 表示不自動切換
- 1 默認值,自動切換
- 2 基於MySQL 主從同步的狀態決定是否切換
5配置 server.xml
該文件主要配置的是mycat的用戶名和密碼及mycat的端口號信息配置,mycat的用戶名和密碼和mysql的用戶名密碼是分開的,應用連接mycat就用這個用戶名和密碼。
root@ebj-rd-02:/srv/mycat/conf# cat server.xml
<?xml version="1.0" encoding="UTF-8"?>
<!-- - - Licensed under the Apache License, Version 2.0 (the "License");
- you may not use this file except in compliance with the License. - You
may obtain a copy of the License at - - http://www.apache.org/licenses/LICENSE-2.0
- - Unless required by applicable law or agreed to in writing, software -
distributed under the License is distributed on an "AS IS" BASIS, - WITHOUT
WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - See the
License for the specific language governing permissions and - limitations
under the License. -->
<!DOCTYPE mycat:server SYSTEM "server.dtd">
<mycat:server xmlns:mycat="http://org.opencloudb/">
<system>
<property name="defaultSqlParser">druidparser</property>
<property name="serverPort">18066</property>
<property name="managerPort">19066</property>
<property name="charset">utf8</property>
<property name="idleTimeout">30000000</property>
<!-- <property name="useCompression">1</property>--> <!--1爲開啓mysql壓縮協議-->
<!-- <property name="processorBufferChunk">40960</property> -->
<!--
<property name="processors">1</property>
<property name="processorExecutor">32</property>
-->
<!--默認是65535 64K 用於sql解析時最大文本長度 -->
<!--<property name="maxStringLiteralLength">65535</property>-->
<!--<property name="sequnceHandlerType">0</property>-->
<!--<property name="backSocketNoDelay">1</property>-->
<!--<property name="frontSocketNoDelay">1</property>-->
<!--<property name="processorExecutor">16</property>-->
<!--
<property name="mutiNodeLimitType">1</property> 0:開啓小數量級(默認) ;1:開啓億級數據排序
<property name="mutiNodePatchSize">100</property> 億級數量排序批量
<property name="processors">32</property> <property name="processorExecutor">32</property>
<property name="serverPort">8066</property> <property name="managerPort">9066</property>
<property name="idleTimeout">300000</property> <property name="bindIp">0.0.0.0</property>
<property name="frontWriteQueueSize">4096</property> <property name="processors">32</property> -->
</system>
<user name="test">
<property name="password">test_123</property>
<property name="schemas">mydb</property>
</user>
<user name="user">
<property name="password">user_123</property>
<property name="schemas">mydb</property>
<property name="readOnly">true</property>
</user>
<!--
<quarantine>
<whitehost>
<host host="127.0.0.1" user="mycat"/>
<host host="127.0.0.2" user="mycat"/>
</whitehost>
<blacklist check="false"></blacklist>
</quarantine>
-->
</mycat:server>
文件終於參數說明:
serverPort設置mycat的服務端口,默認爲8066;
managerPort設置mycat的管理端口,默認爲9066;
idleTimeout設置mycat的空閒超時時間;
user設置mycat的訪問相關schema的用戶名及密碼;
6.配置日誌文件的路徑及日誌級別:
root@ebj-rd-02:/srv/mycat/conf# cat log4j.xml
<?xml version="1.0" encoding="UTF-8"?>
<!--
- Copyright 1999-2012 Alibaba Group.
-
- Licensed under the Apache License, Version 2.0 (the "License");
- you may not use this file except in compliance with the License.
- You may obtain a copy of the License at
-
- http://www.apache.org/licenses/LICENSE-2.0
-
- Unless required by applicable law or agreed to in writing, software
- distributed under the License is distributed on an "AS IS" BASIS,
- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- See the License for the specific language governing permissions and
- limitations under the License.
-->
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
<appender name="ConsoleAppender" class="org.apache.log4j.ConsoleAppender">
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d{MM-dd HH:mm:ss.SSS} %5p [%t] (%F:%L) -%m%n" />
</layout>
</appender>
<appender name="FILE" class="org.apache.log4j.RollingFileAppender">
<param name="file" value="/data/log/mycat/mycat.log" />
<param name="Append" value="false"/>
<param name="MaxFileSize" value="1000KB"/>
<param name="MaxBackupIndex" value="10"/>
<param name="encoding" value="UTF-8" />
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d{MM/dd HH:mm:ss.SSS} %5p [%t] (%F:%L) -%m%n" />
</layout>
</appender>
<root>
<level value="info" />
<appender-ref ref="FILE" />
<!--<appender-ref ref="FILE" />-->
</root>
</log4j:configuration>
文件終於參數說明:
<level value="debug" />表示設置mycat的日誌級別爲調試模式,默認爲info;
<param name="file" value="/data/log/mycat/mycat.log" />表示設置mycat的日誌文件路徑爲/data/log/mycat/mycat.log
7.mycat日常管理
root@ebj-rd-02:/srv/mycat# ./bin/mycat --help
Usage: ./bin/mycat { console | start | stop | restart | status | dump }
登錄mycat讀寫分離服務:
mysql -utest -ptest_123 -P18066 -h127.0.0.1
登錄mycat管理端:
mysql -utest -ptest_123 -P19066 -h127.0.0.1
在事務中,通過/*balance*/強制讀取主數據庫數據:
MySQL [mydb]> begin;
MySQL [mydb]> /*balance*/select * from mytest1;
MySQL [mydb]> commit;
查看mycat管理端的命令幫助:
MySQL [(none)]> show @@help;
8.部署中的異常處理:
MySQL [(none)]> use test;
Database changed
MySQL [test]> show tables;
ERROR 1184 (HY000): Unknown charsetIndex:192
MySQL [test]> select * from mytest;
ERROR 1184 (HY000): Unknown charsetIndex:192
MySQL [test]> exit
該異常是字符集問題引起的數據庫不能連接成功
在conf/index_to_charset.properties文件中增加與自己mysql服務器匹配的字符集即可:
root@ebj-rd-02:/srv/mycat/conf# tail -1 index_to_charset.properties
192=utf8
root@ebj-rd-02:/srv/mycat/conf#