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

This article mainly explains "how to configure MyCat fragments". Friends who are interested may wish to have a look. The method introduced in this paper is simple, fast and practical. Now let the editor take you to learn "how to configure MyCat fragments"!

MyCat Architecture MyCat Core Concepts Schema

Schema: it specifies the logical database (equivalent to MySQL's database database)

Table

Table: logical table (equivalent to MySQL's table table)

DataNode

DataNode: the physical node that actually stores the data

DataHost

DataHost: the database host where the storage node resides (specify the connection information for the MySQL database)

User

Users of User:MyCat (similar to MySQL users, supporting multiple users)

MyCat mainly solves the problem of mass data preservation II. Query Optimization MyCat support for multiple databases

MyCat fragmentation strategy

MyCAT supports horizontal and vertical sharding: horizontal sharding: data from a table is divided into multiple nodes, separated by rows. Vertical fragmentation: multiple tables in a database are stored on node 1, B on node 2, and C on node 3.

MyCAT implements slicing by defining the sharding rules of the table. Each table can be bundled with a sharding rule, and each slicing rule specifies a shard field and binds a function to realize the dynamic slicing algorithm.

Schema

Schema: logical library, corresponding to the Database (database) in MySQL. A logical library defines the included Table.

Table

Table: a table, that is, a table stored in a physical database, unlike a traditional database, where the table needs to declare its stored logical data node DataNode. Here you can specify the sharding rules for the table.

DataNode

The logical data node of the DataNode:MyCAT is the specific physical node where the table is stored, also known as the sharding node, which is associated to a specific database at the back end through DataHost.

DataHost

DataHost: defines the access address of a physical library, which is used to bind to Datanode

MyCat installation and download MyCatwget http://dl.mycat.io/1.6-RELEASE/Mycat-server-1.6-RELEASE-20161028204710-

Linux.tar.gz decompress tar-zxvf Mycat-server-1.6-RELEASE-20161028204710-linux.tar.gz into mycat/bin, launch MyCat- startup command:. / mycat start

-stop command:. / mycat stop

-restart command:. / mycat restart

-View status:. / mycat status

Clients accessing MyCat use mysql to connect directly to the mycat service. The default service port is [8066]

Mysql-uroot-p123456-h227.0.0.1-P8066 MyCat shard configuration schema.xml what is schema.xml

As one of the important configuration files in Mycat, schema.xml manages the mapping relationship between Mycat logic library, table, slicing rules, DataNode and DataHost. Understanding these configurations is a prerequisite for the correct use of Mycat. The schema tag is used to define the logical library in the MyCat instance. The Table tag defines the logical table in MyCat. The dataNode tag defines the data node in MyCat, which is what we usually call data fragmentation. The dataHost tag also exists as the lowest tag in the mycat logic library, directly defining the specific database instance, read-write separation configuration and heartbeat statements.

Schema.xml configuration

Configure Server.xml

Server.xml introduction

Server.xml saves almost all the system configuration information needed by mycat. The most common is to configure user names, passwords, and permissions here.

Server.xml configuration

Configure rule.xml

Rule.xml defines the rules involved in splitting the table. We can flexibly use different slicing calculations on the table.

Method, or use the same algorithm for the table but with different specific parameters. There are mainly two marks tableRule and function in this document.

Sign it. In the specific use process, you can add tableRule and function as needed.

This configuration file does not need to be modified and can be used by default.

Select user ()

Introduction to configuring server.xmlserver.xml

Server.xml saves almost all the system configuration information needed by mycat. The most common is to configure user names, passwords, and permissions here.

Server.xml configuration

Druidparser

Mycat

TESTDB

Configure rule.xml

Rule.xml defines the rules involved in splitting the table. We can flexibly use different slicing algorithms for the table, or use the same algorithm for the table but with different specific parameters. There are mainly two tags tableRule and function in this document. In the specific use process, you can add tableRule and function as needed. This configuration file can be modified without modification and can be used by default.

Sharding_id

Hash-int

Partition-hash-int.txt

TableRule tag configuration instructions:

The name attribute specifies a unique name, and the rule tag, which identifies different table rules, specifies which column in the physical table to split and which routing algorithm to use. Specify the name of the column to split within the columns. Algorithm uses the name attribute in the function tag. Connection table rules and specific routing algorithms. Of course, multiple table rules can be connected to the same routing algorithm. Used within the table tag. Let logical tables use this rule for slicing.

Function tag configuration instructions:

Name specifies the name of the algorithm. Class defines the specific class name of the routing algorithm. Property is some of the attributes that the specific algorithm needs to use.

Several commonly used slicing rules continuous slicing date column partitioning method

Create_time

Sharding-by-date

Yyyy-MM-dd

2014-01-01

ten

Configuration instructions:

TableRule tag:

Columns: identifies the table field to be sliced

Algorithm: specify sharding function

Function tag:

DateFormat: date format

SBeginDate: start date

SPartionDay: partition days, that is, by default, one partition is separated for 10 days from the start date.

II. Scope agreement

Configuration instructions:

TableRule tag:

Create_time

Sharding-by-month

Yyyy-MM-dd

2014-01-01

Create_time

Sharding-by-hour

twenty-four

Configuration description tableRule tag: columns: identify the table field to be sharded algorithm: specify sharding function function tag: dateFormat: date format sBeginDate: start date sPartionDay: partition days, that is, 10 days separated by default from the start date

Scope convention

User_id

Rang-long

Autopartition-long.txt

Configuration description tableRule tag: columns: identify the table field to be sharded algorithm: specify sharding function function tag: mapFile: specify the name of the configuration file required by the sharding function

Autopartition-long.txt file content: all node configurations start with 0, and 0 represents node 1. This configuration is very simple, that is, a possible id range is defined in advance corresponding to a certain shard.

# range start-end, data node index

# Knights 1000, Manners 10000.

0-500M=0 0-1000

500M-1000M=1 101-200 1

201-300 2

1000M-1500M=2

Default=0

# or the following

# 0-10000000000000

# 10000001-20000000 / 1

Advantages: expansion does not need to migrate data disadvantages: hot data, concurrency restrictions

Discrete piecewise enumeration

User_id

Hash-int

Partition-hash-int.txt

0

0

Configuration description tableRule tag: columns: identify the table field to be sharded algorithm: specify sharding function function tag: mapFile: specify the name of the configuration file required by the sharding function type: the default value is 0, 0 means Integer, non-zero means String defaultNode: specify the default node, less than 0 means no default node, 0 or greater than 0 means setting the default node, 0 represents node 1.

The role of the default node: when enumerating fragments, if you encounter an unrecognized enumeration value, let it route to the default node. If the default node is not configured (a defaultNode value less than 0 means that the default node is not configured), an error will be reported when an unrecognized enumeration value is encountered:

Partition-hash-int.txt configuration:

Column 10, 000'0 equals 10000 to put the first shard.

10010 # 1

Male = 0

Female = 1

Beijing=0

Tianjin=1

Zhanghai=2

Modeling method

User_id

Mod-long

three

TableRule tag: columns: identify the table field to be sharded algorithm: specify the sharding function function tag: count: number of nodes

Consistent hash

User_id

Murmur

0

two

one hundred and sixty

Wait, there are some other fragments, here, do not explain for the time being

Test shard

Store the merchandise table in pieces on three data nodes.

Create a tabl

After the configuration is complete, restart mycat. Use the mysql client to connect to the mycat to create the table.

CREATE TABLE item (

Id int (11) NOT NULL

Name varchar (20) DEFAULT NULL

PRIMARY KEY (id)

) ENGINE=InnoDB DEFAULT CHARSET=utf8 fragmentation test

Sharding policy specified as "auto-sharding-long" sharding rule specified as "mod-long"

At this point, I believe you have a deeper understanding of "how to configure MyCat fragments". You might as well do it in practice. Here is the website, more related content can enter the relevant channels to inquire, follow us, continue to learn!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.