Shulou(Shulou.com)06/01 Report--

Deploy mycat

Mycat runs on java, check java version

[root@node119 ~] # java-versionopenjdk version "1.8.0,171" OpenJDK Runtime Environment (build 1.8.0_171-b10) OpenJDK 64-Bit Server VM (build 25.171-b10, mixed mode)

Configure java variables

[root@node119 ~] # vim / etc/profileexport JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.171-7.b10.el7.x86_64export CLASSPATH=.:$JAVA_HOME/jre/lib/rt.jar:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jarexport PATH=$PATH:$JAVA_HOME/bin

Mycat download address

Http://dl.mycat.io/cd / opttar zxvf Mycat-server-1.6.5-release-20180122220033-linux.tar.gz

General architecture diagram

Core concept schema: logical database datanode composed of multiple databases: after sharding the data, a large table is assigned to different sharding databases, and the database where each table shard resides is called the sharding node datahost: the machine where one or more sharding nodes are located is the node host.

The concept of sharding node and node host is a little difficult to understand. For example, a 100W table is divided into two tables, the first 50W is in the database of host A, and the last 50W is in the database of host B, and the database where the table is located is called the sharding node of this table; it is impossible to have only one table in a host, there will be many sharding tables on the host, and the host is called the node host, that is, datanode=database@datahost

A simple explanation of the mycat principle:

Block-> analyze-> forward-> result processing-> return to the user

Mycat analysis roughly includes: fragmentation analysis, routing analysis, read-write separation analysis, cache analysis and so on. In the next experiment, we will analyze log to see how mycat works.

Requirement description

There is a library of three tables.

MySQL [mycat01] > show tables;+-+ | Tables in mycat01 | +-+ | T1 | | T2 | | T3 | +-Sub-library:

T1 in mysql cluster

T2 in percona cluster

Sub-table:

T3 id models 1024 less than 1024 in mysql clusters, and more than 1024 in percona clusters

Read-write separation:

T1 writehost is node115

Stand by writehost is node116

Readhost is node117

T2 writehost is node126

Readhost is node123 node125

Configuration file # two mycat users are created here (note: it has nothing to do with back-end mysql users) root has read and write permissions, and user has read permissions [root@node119 ~] # vim / opt/mycat/conf/server.xml 123456 mycat01 user mycat01 true

Balance= "0" does not enable read-write separation, that is, all read-write operations are sent to writehost

All readhost and stand by writehost of balance= "1" participate in the load of select statements, that is, in mutual master-slave mode.

Balance= "2" all read and write operations are randomly distributed on readhost and writehost

Balance= "3" all read requests are sent to the readhost corresponding to writehost, reducing the pressure on writehost

WriteType= "0" all writes are sent to the first writehost, and then switched to the second after the first writehots down without failback

[root@node119 ~] # vim / opt/mycat/conf/schema.xml # schema name is the mapped logical library name, that is, the shard node where the name # T1 is seen by the user accessing mycat is mysql. In other words, mycat will only find T1 from the mysql cluster. # mycat will look for T3 select user () from two shard nodes. Select user () [root@node119 ~] # vim / opt/mycat/conf/rule.xml 2 512

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