57 Star 280 Fork 111

GVPMycatOne / Mycat-Server

加入 Gitee
与超过 1200万 开发者一起发现、参与优秀开源项目,私有仓库也完全免费 :)
免费加入
克隆/下载
贡献代码
同步代码
取消
提示: 由于 Git 不支持空文件夾,创建文件夹后会生成空的 .keep 文件
Loading...
README
GPL-2.0

Mycat1

官网: http://mycatone.top

gitee github

提交代码,可以开issue,写清楚代码改动或者联系qq:1019100252

mycat1.6权威指南 yuque pdf

客户端连接配置 gitee github

Stargazers over time

Mycat志愿者开发群:332702697,106088787

GitHub issues GitHub forks GitHub stars MyCAT

MyCAT is an Open-Source software, “a large database cluster” oriented to enterprises. MyCAT is an enforced database which is a replacement for MySQL and supports transaction and ACID. Regarded as MySQL cluster of enterprise database, MyCAT can take the place of expensive Oracle cluster. MyCAT is also a new type of database, which seems like a SQL Server integrated with the memory cache technology, NoSQL technology and HDFS big data. And as a new modern enterprise database product, MyCAT is combined with the traditional database and new distributed data warehouse. In a word, MyCAT is a fresh new middleware of database.

Mycat’s target is to smoothly migrate the current stand-alone database and applications to cloud side with low cost and to solve the bottleneck problem caused by the rapid growth of data storage and business scale.

2020年1月1日合拼了一个PR,优化PartionByLong的分片算法,数据不均衡的问题,所以该分片算法与此前的PartionByLong的数据分布不一致,即1.675之后与之前的版本不兼容 MyCAT1.6不支持一个SQL包含多个语句

旧Mycat升级fastjson,把pom.xml中fastjson的版本更改即可

1.6的bug: 批处理插入,多语句,堆外合拼,请大家要避开这些功能

全局序列号语法

INSERT INTO `travelrecord` (`id`,user_id) VALUES ('next value for MYCATSEQ_GLOBAL',"xxx");

更新Druid 1.1.10版本的分支独立维护在 gitee github

Features

  • Supports SQL 92 standard
  • Supports MySQL cluster, used as a Proxy
  • Supports JDBC connection with ORACLE, DB2, SQL Server, simulated as normal MySQL Server connection
  • Supports MySQL cluster, percona cluster or mariadb cluster, providing high availability of data fragmentation clusters
  • Supports automatic failover and high availability
  • Supports separation of read and write, dual-master with multi-slave, single-master with multi-master of MySQL model
  • Supports global table, automatically fragment data into multiple nodes for efficient relational query
  • Supports the unique fragmentation strategy based on ER-relation for efficient relational query
  • Supports multiple platforms, easy deployment and implementation

Advantage

  • Based on Alibaba's open-source project Cobar github,gitee, whose stability, reliability, excellent architecture and performance, as well as many mature use-cases make MyCAT have a good starting. Standing on the shoulders of giants, MyCAT feels confident enough to go farther.
  • Extensively drawing on the best open-source projects and innovative ideas, which are integrated into the Mycat’s gene, make MyCAT be ahead of the other current similar open-source projects, even beyond some commercial products.
  • MyCAT behind a strong technical team whose participants are experienced more than five years including some senior software engineer, architect, DBA, etc. Excellent technical team to ensure the product quality of Mycat.
  • MyCAT does not rely on any commercial company. It’s unlike some open-source projects whose important features is enclosed in its commercial products and making open-source projects like a decoration.

Roadmap

  • On the basis of MySQL’s support, MyCAT add more support of commercial open-source database, including native support of PostgreSQL, FireBird and other open-source databases, as well as indirect support via JDBC of other non-open-source databases such as Oracle, DB2, SQL Server etc.
  • More intelligent self-regulating properties, such as automatic statistical analysis of SQL, automatic creating and adjusting indexes. Based on the frequency of read and write, MyCAT automatically optimizes caching and backup strategies
  • Achieve a more comprehensive monitoring and management
  • Integrated with HDFS, provide SQL commands, load databases into HDFS for rapid analysis
  • Integrated excellent open-source reporting tools to make MyCAT have data analysis capability

Download

There are some compiled binary installation packages in Mycat-download project on github at Mycat-download.

Document

There are some documents in Mycat-doc project on github at [Mycat-doc]

gitee

github

Mycat 简单demo,具体参考Mycat权威指南

Mycat前世今生

2013年阿里的Cobar在社区使用过程中发现存在一些比较严重的问题,及其使用限制,经过Mycat发起人第一次改良,第一代改良版——Mycat诞生。 Mycat开源以后,一些Cobar的用户参与了Mycat的开发,最终Mycat发展成为一个由众多软件公司的实力派架构师和资深开发人员维护的社区型开源软件。

2014年Mycat首次在上海的《中华架构师》大会上对外宣讲,更多的人参与进来,随后越来越多的项目采用了Mycat。

2015年5月,由核心参与者们一起编写的第一本官方权威指南《Mycat权威指南》电子版发布,累计超过500本,成为开源项目中的首创。

2015年10月为止,Mycat项目总共有16个Committer。

截至2015年11月,超过300个项目采用Mycat,涵盖银行、电信、电子商务、物流、移动应用、O2O的众多领域和公司。

截至2015年12月,超过4000名用户加群或研究讨论或测试或使用Mycat。

Mycat是基于开源cobar演变而来,我们对cobar的代码进行了彻底的重构,使用NIO重构了网络模块,并且优化了Buffer内核,增强了聚合,Join等基本特性,同时兼容绝大多数数据库成为通用的数据库中间件。1.4 版本以后 完全的脱离基本cobar内核,结合Mycat集群管理、自动扩容、智能优化,成为高性能的中间件。我们致力于开发高性能数据库中间而努力。永不收费,永不闭源,持续推动开源社区的发展。

Mycat吸引和聚集了一大批业内大数据和云计算方面的资深工程师,Mycat的发展壮大基于开源社区志愿者的持续努力,感谢社区志愿者的努力让Mycat更加强大,同时我们也欢迎社区更多的志愿者,特别是公司能够参与进来,参与Mycat的开发,一起推动社区的发展,为社区提供更好的开源中间件。

Mycat还不够强大,Mycat还有很多不足,欢迎社区志愿者的持续优化改进。

关键特性

支持SQL92标准

遵守Mysql原生协议,跨语言,跨平台,跨数据库的通用中间件代理。

基于心跳的自动故障切换,支持读写分离,支持MySQL主从,以及galera cluster集群。

支持Galera for MySQL集群,Percona Cluster或者MariaDB cluster

基于Nio实现,有效管理线程,高并发问题。

支持数据的多片自动路由与聚合,支持sum,count,max等常用的聚合函数。

支持单库内部任意join,支持跨库2表join,甚至基于caltlet的多表join。

支持通过全局表,ER关系的分片策略,实现了高效的多表join查询。

支持多租户方案。

支持分布式事务(弱xa)。

支持全局序列号,解决分布式下的主键生成问题。

分片规则丰富,插件化开发,易于扩展。

强大的web,命令行监控。

支持前端作为mysq通用代理,后端JDBC方式支持Oracle、DB2、SQL Server 、 mongodb 、巨杉。

支持密码加密

支持服务降级

支持IP白名单

支持SQL黑名单、sql注入攻击拦截

支持分表(1.6)

集群基于ZooKeeper管理,在线升级,扩容,智能优化,大数据处理(2.0开发版)。

Mycat安装与使用

下载:

具体下载哪个版本以发布为准,推荐1.67.

安装:

下载的文件直接解压即可。

运行:

linux:

./mycat start 启动

./mycat stop 停止

./mycat console 前台运行

./mycat install 添加到系统自动启动(暂未实现)

./mycat remove 取消随系统自动启动(暂未实现)

./mycat restart 重启服务

./mycat pause 暂停

./mycat status 查看启动状态

win:

直接运行startup_nowrap.bat,如果出现闪退,在cmd 命令行运行,查看出错原因。

内存配置:

启动前,一般需要修改JVM配置参数,打开conf/wrapper.conf文件,如下行的内容为2G和2048,可根据本机配置情况修改为512M或其它值。 以下配置跟jvm参数完全一致,可以根据自己的jvm参数调整。

Java Additional Parameters

wrapper.java.additional.1=

wrapper.java.additional.1=-DMYCAT_HOME=.

wrapper.java.additional.2=-server

#wrapper.java.additional.3=-XX:MaxPermSize=64M

wrapper.java.additional.4=-XX:+AggressiveOpts

wrapper.java.additional.5=-XX:MaxDirectMemorySize=100m

wrapper.java.additional.6=-Dcom.sun.management.jmxremote

wrapper.java.additional.7=-Dcom.sun.management.jmxremote.port=1984

wrapper.java.additional.8=-Dcom.sun.management.jmxremote.authenticate=false

wrapper.java.additional.9=-Dcom.sun.management.jmxremote.ssl=false

wrapper.java.additional.10=-Xmx100m

wrapper.java.additional.11=-Xms100m

wrapper.java.additional.12=-XX:+UseParNewGC

wrapper.java.additional.13=-XX:+UseConcMarkSweepGC

wrapper.java.additional.14=-XX:+UseCMSCompactAtFullCollection

wrapper.java.additional.15=-XX:CMSFullGCsBeforeCompaction=0

wrapper.java.additional.16=-XX:CMSInitiatingOccupancyFraction=70

以下配置作废:

wrapper.java.initmemory=3

wrapper.java.maxmemory=64

Mycat连接测试:

测试mycat与测试mysql完全一致,mysql怎么连接,mycat就怎么连接。

推荐先采用命令行测试:

mysql -uroot -proot -P8066 -h127.0.0.1

如果采用工具连接,1.4,1.3目前部分工具无法连接,会提示database not selected,建议采用高版本,navicat测试。1.5已经修复了部分工具连接。

Mycat配置入门

配置:

--bin 启动目录

--conf 配置目录存放配置文件:

  --server.xml:是Mycat服务器参数调整和用户授权的配置文件。

  --schema.xml:是逻辑库定义和表以及分片定义的配置文件。

  --rule.xml:  是分片规则的配置文件,分片规则的具体一些参数信息单独存放为文件,也在这个目录下,配置文件修改需要重启MyCAT。

  --log4j.xml: 日志存放在logs/log中,每天一个文件,日志的配置是在conf/log4j.xml中,根据自己的需要可以调整输出级别为debug                           debug级别下,会输出更多的信息,方便排查问题。

  --autopartition-long.txt,partition-hash-int.txt,sequence_conf.properties, sequence_db_conf.properties 分片相关的id分片规则配置文件

  --lib	    MyCAT自身的jar包或依赖的jar包的存放目录。

  --logs        MyCAT日志的存放目录。日志存放在logs/log中,每天一个文件

下面图片描述了Mycat最重要的3大配置文件:

逻辑库配置:

配置server.xml

添加两个mycat逻辑库:user,pay
system 参数是所有的mycat参数配置,比如添加解析器:defaultSqlParser,其他类推
user 是用户参数。

<system>

	<property name="defaultSqlParser">druidparser</property>

</system>

<user name="mycat">

	<property name="password">mycat</property>

	<property name="schemas">user,pay</property>

</user>

编辑schema.xml

修改dataHost和schema对应的连接信息,user,pay 垂直切分后的配置如下所示:

schema 是实际逻辑库的配置,user,pay分别对应两个逻辑库,多个schema代表多个逻辑库。

dataNode是逻辑库对应的分片,如果配置多个分片只需要多个dataNode即可。

dataHost是实际的物理库配置地址,可以配置多主主从等其他配置,多个dataHost代表分片对应的物理库地址,下面的writeHost、readHost代表该分片是否配置多写,主从,读写分离等高级特性。

以下例子配置了两个writeHost为主从。

<schema name="user" checkSQLschema="false" sqlMaxLimit="100" dataNode="user" />
<schema name="pay"  checkSQLschema="false" sqlMaxLimit="100" dataNode="pay" >
   <table name="order" dataNode="pay1,pay2" rule="rule1"/>
</schema>

<dataNode name="user" dataHost="host" database="user" />
<dataNode name="pay1" dataHost="host" database="pay1" />
<dataNode name="pay2" dataHost="host" database="pay2" />

<dataHost name="host" maxCon="1000" minCon="10" balance="0"
   writeType="0" dbType="mysql" dbDriver="native">
   <heartbeat>select 1</heartbeat>
   <!-- can have multi write hosts -->
   <writeHost host="hostM1" url="192.168.0.2:3306" user="root" password="root" />
   <writeHost host="hostM2" url="192.168.0.3:3306" user="root" password="root" />
</dataHost>

Mycat逻辑库、系统参数配置

配置Mycat环境参数

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE mycat:server SYSTEM "server.dtd">
<mycat:server xmlns:mycat="http://org.opencloudb/">
   <system>
	  <property name="defaultSqlParser">druidparser</property>
    </system> 
 </mycat:server>

如例子中配置的所有的Mycat参数变量都是配置在server.xml 文件中,system标签下配置所有的参数,如果需要配置某个变量添加相应的配置即可,例如添加启动端口8066,默认为8066:

   <property name="serverPort">8066</property>

其他所有变量类似。

配置Mycat逻辑库与用户

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE mycat:server SYSTEM "server.dtd">
<mycat:server xmlns:mycat="http://org.opencloudb/">
<user name="mycat">
	<property name="password">mycat</property>
	<property name="schemas">TESTDB</property>
</user>
 </mycat:server>

如例子中配置的所有的Mycat连接的用户与逻辑库映射都是配置在server.xml 文件中,user标签下配置所有的参数,例如例子中配置了一个mycat用户供应用连接到mycat,同时mycat 在schema.xml中配置后了一个逻辑库TESTDB,配置好逻辑库与用户的映射关系。

逻辑库、表分片配置

配置逻辑库(schema)

Mycat作为一个中间件,实现mysql协议,那么对前端应用连接来说就是一个数据库,也就有数据库的配置,mycat的数据库配置是在schema.xml中配置,配置好后映射到server.xml里面的用户就可以了。

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mycat:schema SYSTEM "schema.dtd">

<mycat:schema  xmlns:mycat="http://org.opencloudb/">
  <schema name="TESTDB" checkSQLschema="true" sqlMaxLimit="100" dataNode="dn1">
      <table name="t_user" dataNode="dn1,dn2" rule="sharding-by-mod2"/>
      <table name="ht_jy_login_log" primaryKey="ID" dataNode="dn1,dn2" rule="sharding-by-date_jylog"/>
  </schema>
  <dataNode name="dn1" dataHost="localhost1" database="mycat_node1"/>
  <dataNode name="dn2" dataHost="localhost1" database="mycat_node2"/>
  
  <dataHost name="localhost1" writeType="0" switchType="1" slaveThreshold="100" balance="1" dbType="mysql" maxCon="10" minCon="1" dbDriver="native">
    <heartbeat>show status like 'wsrep%'</heartbeat>
    <writeHost host="hostM1" url="127.0.0.1:3306" user="root" password="root" >
    </writeHost>  
  </dataHost>
</mycat:schema >

上面例子配置了一个逻辑库TESTDB,同时配置了t_user,ht_jy_login_log两个分片表。

逻辑表配置

      <table name="t_user" dataNode="dn1,dn2" rule="sharding-by-mod2"/>

table 标签 是逻辑表的配置 其中

name代表表名,

dataNode代表表对应的分片,

Mycat默认采用分库方式,也就是一个表映射到不同的库上,

rule代表表要采用的数据切分方式,名称对应到rule.xml中的对应配置,如果要分片必须配置。

配置分片(dataNode)

  <dataNode name="dn1" dataHost="localhost1" database="mycat_node1"/>
  <dataNode name="dn2" dataHost="localhost1" database="mycat_node2"/>

表切分后需要配置映射到哪几个数据库中,Mycat的分片实际上就是库的别名,例如上面例子配置了两个分片dn1,dn2 分别对应到物理机映射dataHost localhost1 的两个库上。

配置物理库分片映射(dataHost)

  <dataHost name="localhost1" writeType="0" switchType="1" slaveThreshold="100" balance="1" dbType="mysql" maxCon="10" minCon="1" dbDriver="native">
    <heartbeat>show status like 'wsrep%'</heartbeat>
    <writeHost host="hostM1" url="127.0.0.1:3306" user="root" password="root" >
    </writeHost>  
  </dataHost>

Mycat作为数据库代理需要逻辑库,逻辑用户,表切分后需要配置分片,分片也就需要映射到真实的物理主机上,至于是映射到一台还是一台的多个实例上,Mycat并不关心,只需要配置好映射即可,例如例子中:

配置了一个名为localhost1的物理主机(dataHost)映射。

heartbeat 标签代表Mycat需要对物理库心跳检测的语句,正常情况下生产案例可能配置主从,或者多写 或者单库,无论哪种情况Mycat都需要维持到数据库的数据源连接,因此需要定时检查后端连接可以性,心跳语句就是来作为心跳检测。

writeHost 此标签代表 一个逻辑主机(dataHost)对应的后端的物理主机映射,例如例子中写库hostM1 映射到127.0.0.1:3306。如果后端需要做读写分离或者多写 或者主从则通过配置 多个writeHost 或者readHost即可。

dataHost 标签中的 writeType balance 等标签则是不同的策略,具体参考指南。

Mycat 表切分规则配置

表切分规则

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mycat:rule SYSTEM "rule.dtd">

<mycat:rule  xmlns:mycat="http://org.opencloudb/">
  <tableRule name="sharding-by-hour">
    <rule>
      <columns>createTime</columns>
      <algorithm>sharding-by-hour</algorithm>
    </rule>
  </tableRule>
  
  <function name="sharding-by-hour" class="org.opencloudb.route.function.LatestMonthPartion">
    <property name="splitOneDay">24</property>
  </function>
   
</mycat:rule >

数据切分中作为表切分规则中最重要的配置,表的切分方式决定了数据切分后的性能好坏,因此也是最重要的配置。

如上面例子配置了一个切分规则,名为sharding-by-hour 对应的切分方式(function )是按日期切分,该配置中:

tableRule

name 为schema.xml 中table 标签中对应的 rule="sharding-by-hour" ,也就是配置表的分片规则,

columns 是表的切分字段: createTime 创建日期。

algorithm 是规则对应的切分规则:映射到function 的name。

function

function 配置是分片规则的配置。

name 为切分规则的名称,名字任意取,但是需要与tableRule 中匹配。

class 是切分规则对应的切分类,写死,需要哪种规则则配置哪种,例如本例子是按小时分片:org.opencloudb.route.function.LatestMonthPartion

property 标签是切分规则对应的不同属性,不同的切分规则配置不同。

GNU GENERAL PUBLIC LICENSE Version 2, June 1991 Copyright (C) 1989, 1991 Free Software Foundation, Inc., <http://fsf.org/> 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. Preamble The licenses for most software are designed to take away your freedom to share and change it. By contrast, the GNU General Public License is intended to guarantee your freedom to share and change free software--to make sure the software is free for all its users. This General Public License applies to most of the Free Software Foundation's software and to any other program whose authors commit to using it. (Some other Free Software Foundation software is covered by the GNU Lesser General Public License instead.) You can apply it to your programs, too. When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software (and charge for this service if you wish), that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new free programs; and that you know you can do these things. To protect your rights, we need to make restrictions that forbid anyone to deny you these rights or to ask you to surrender the rights. These restrictions translate to certain responsibilities for you if you distribute copies of the software, or if you modify it. For example, if you distribute copies of such a program, whether gratis or for a fee, you must give the recipients all the rights that you have. You must make sure that they, too, receive or can get the source code. And you must show them these terms so they know their rights. We protect your rights with two steps: (1) copyright the software, and (2) offer you this license which gives you legal permission to copy, distribute and/or modify the software. Also, for each author's protection and ours, we want to make certain that everyone understands that there is no warranty for this free software. If the software is modified by someone else and passed on, we want its recipients to know that what they have is not the original, so that any problems introduced by others will not reflect on the original authors' reputations. Finally, any free program is threatened constantly by software patents. We wish to avoid the danger that redistributors of a free program will individually obtain patent licenses, in effect making the program proprietary. To prevent this, we have made it clear that any patent must be licensed for everyone's free use or not licensed at all. The precise terms and conditions for copying, distribution and modification follow. GNU GENERAL PUBLIC LICENSE TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION 0. This License applies to any program or other work which contains a notice placed by the copyright holder saying it may be distributed under the terms of this General Public License. The "Program", below, refers to any such program or work, and a "work based on the Program" means either the Program or any derivative work under copyright law: that is to say, a work containing the Program or a portion of it, either verbatim or with modifications and/or translated into another language. (Hereinafter, translation is included without limitation in the term "modification".) Each licensee is addressed as "you". Activities other than copying, distribution and modification are not covered by this License; they are outside its scope. The act of running the Program is not restricted, and the output from the Program is covered only if its contents constitute a work based on the Program (independent of having been made by running the Program). Whether that is true depends on what the Program does. 1. You may copy and distribute verbatim copies of the Program's source code as you receive it, in any medium, provided that you conspicuously and appropriately publish on each copy an appropriate copyright notice and disclaimer of warranty; keep intact all the notices that refer to this License and to the absence of any warranty; and give any other recipients of the Program a copy of this License along with the Program. You may charge a fee for the physical act of transferring a copy, and you may at your option offer warranty protection in exchange for a fee. 2. You may modify your copy or copies of the Program or any portion of it, thus forming a work based on the Program, and copy and distribute such modifications or work under the terms of Section 1 above, provided that you also meet all of these conditions: a) You must cause the modified files to carry prominent notices stating that you changed the files and the date of any change. b) You must cause any work that you distribute or publish, that in whole or in part contains or is derived from the Program or any part thereof, to be licensed as a whole at no charge to all third parties under the terms of this License. c) If the modified program normally reads commands interactively when run, you must cause it, when started running for such interactive use in the most ordinary way, to print or display an announcement including an appropriate copyright notice and a notice that there is no warranty (or else, saying that you provide a warranty) and that users may redistribute the program under these conditions, and telling the user how to view a copy of this License. (Exception: if the Program itself is interactive but does not normally print such an announcement, your work based on the Program is not required to print an announcement.) These requirements apply to the modified work as a whole. If identifiable sections of that work are not derived from the Program, and can be reasonably considered independent and separate works in themselves, then this License, and its terms, do not apply to those sections when you distribute them as separate works. But when you distribute the same sections as part of a whole which is a work based on the Program, the distribution of the whole must be on the terms of this License, whose permissions for other licensees extend to the entire whole, and thus to each and every part regardless of who wrote it. Thus, it is not the intent of this section to claim rights or contest your rights to work written entirely by you; rather, the intent is to exercise the right to control the distribution of derivative or collective works based on the Program. In addition, mere aggregation of another work not based on the Program with the Program (or with a work based on the Program) on a volume of a storage or distribution medium does not bring the other work under the scope of this License. 3. You may copy and distribute the Program (or a work based on it, under Section 2) in object code or executable form under the terms of Sections 1 and 2 above provided that you also do one of the following: a) Accompany it with the complete corresponding machine-readable source code, which must be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange; or, b) Accompany it with a written offer, valid for at least three years, to give any third party, for a charge no more than your cost of physically performing source distribution, a complete machine-readable copy of the corresponding source code, to be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange; or, c) Accompany it with the information you received as to the offer to distribute corresponding source code. (This alternative is allowed only for noncommercial distribution and only if you received the program in object code or executable form with such an offer, in accord with Subsection b above.) The source code for a work means the preferred form of the work for making modifications to it. For an executable work, complete source code means all the source code for all modules it contains, plus any associated interface definition files, plus the scripts used to control compilation and installation of the executable. However, as a special exception, the source code distributed need not include anything that is normally distributed (in either source or binary form) with the major components (compiler, kernel, and so on) of the operating system on which the executable runs, unless that component itself accompanies the executable. If distribution of executable or object code is made by offering access to copy from a designated place, then offering equivalent access to copy the source code from the same place counts as distribution of the source code, even though third parties are not compelled to copy the source along with the object code. 4. You may not copy, modify, sublicense, or distribute the Program except as expressly provided under this License. Any attempt otherwise to copy, modify, sublicense or distribute the Program is void, and will automatically terminate your rights under this License. However, parties who have received copies, or rights, from you under this License will not have their licenses terminated so long as such parties remain in full compliance. 5. You are not required to accept this License, since you have not signed it. However, nothing else grants you permission to modify or distribute the Program or its derivative works. These actions are prohibited by law if you do not accept this License. Therefore, by modifying or distributing the Program (or any work based on the Program), you indicate your acceptance of this License to do so, and all its terms and conditions for copying, distributing or modifying the Program or works based on it. 6. Each time you redistribute the Program (or any work based on the Program), the recipient automatically receives a license from the original licensor to copy, distribute or modify the Program subject to these terms and conditions. You may not impose any further restrictions on the recipients' exercise of the rights granted herein. You are not responsible for enforcing compliance by third parties to this License. 7. If, as a consequence of a court judgment or allegation of patent infringement or for any other reason (not limited to patent issues), conditions are imposed on you (whether by court order, agreement or otherwise) that contradict the conditions of this License, they do not excuse you from the conditions of this License. If you cannot distribute so as to satisfy simultaneously your obligations under this License and any other pertinent obligations, then as a consequence you may not distribute the Program at all. For example, if a patent license would not permit royalty-free redistribution of the Program by all those who receive copies directly or indirectly through you, then the only way you could satisfy both it and this License would be to refrain entirely from distribution of the Program. If any portion of this section is held invalid or unenforceable under any particular circumstance, the balance of the section is intended to apply and the section as a whole is intended to apply in other circumstances. It is not the purpose of this section to induce you to infringe any patents or other property right claims or to contest validity of any such claims; this section has the sole purpose of protecting the integrity of the free software distribution system, which is implemented by public license practices. Many people have made generous contributions to the wide range of software distributed through that system in reliance on consistent application of that system; it is up to the author/donor to decide if he or she is willing to distribute software through any other system and a licensee cannot impose that choice. This section is intended to make thoroughly clear what is believed to be a consequence of the rest of this License. 8. If the distribution and/or use of the Program is restricted in certain countries either by patents or by copyrighted interfaces, the original copyright holder who places the Program under this License may add an explicit geographical distribution limitation excluding those countries, so that distribution is permitted only in or among countries not thus excluded. In such case, this License incorporates the limitation as if written in the body of this License. 9. The Free Software Foundation may publish revised and/or new versions of the General Public License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. Each version is given a distinguishing version number. If the Program specifies a version number of this License which applies to it and "any later version", you have the option of following the terms and conditions either of that version or of any later version published by the Free Software Foundation. If the Program does not specify a version number of this License, you may choose any version ever published by the Free Software Foundation. 10. If you wish to incorporate parts of the Program into other free programs whose distribution conditions are different, write to the author to ask for permission. For software which is copyrighted by the Free Software Foundation, write to the Free Software Foundation; we sometimes make exceptions for this. Our decision will be guided by the two goals of preserving the free status of all derivatives of our free software and of promoting the sharing and reuse of software generally. NO WARRANTY 11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. 12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. END OF TERMS AND CONDITIONS How to Apply These Terms to Your New Programs If you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms. To do so, attach the following notices to the program. It is safest to attach them to the start of each source file to most effectively convey the exclusion of warranty; and each file should have at least the "copyright" line and a pointer to where the full notice is found. {description} Copyright (C) {year} {fullname} This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Also add information on how to contact you by electronic and paper mail. If the program is interactive, make it output a short notice like this when it starts in an interactive mode: Gnomovision version 69, Copyright (C) year name of author Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. This is free software, and you are welcome to redistribute it under certain conditions; type `show c' for details. The hypothetical commands `show w' and `show c' should show the appropriate parts of the General Public License. Of course, the commands you use may be called something other than `show w' and `show c'; they could even be mouse-clicks or menu items--whatever suits your program. You should also get your employer (if you work as a programmer) or your school, if any, to sign a "copyright disclaimer" for the program, if necessary. Here is a sample; alter the names: Yoyodyne, Inc., hereby disclaims all copyright interest in the program `Gnomovision' (which makes passes at compilers) written by James Hacker. {signature of Ty Coon}, 1 April 1989 Ty Coon, President of Vice This General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Lesser General Public License instead of this License.

简介

MyCAT是一个彻底开源、高性能、高可靠性,可弹性扩展的分布式数据库中间件,面向企业应用开发的大数据库集群,支持事务、ACID、MySQL的加强版数据库,通过将业务数据分片到不同的数据库存储节点中,充分利用各节点的计算资源, 极大地提高了数据库的性能,可以视为MySQL集群的企业级数据库。 展开 收起
GPL-2.0
取消

发行版

暂无发行版

贡献者

全部

近期动态

加载更多
不能加载更多了
马建仓 AI 助手
尝试更多
代码解读
代码找茬
代码优化
Java
1
https://gitee.com/MycatOne/Mycat-Server.git
git@gitee.com:MycatOne/Mycat-Server.git
MycatOne
Mycat-Server
Mycat-Server
main

搜索帮助

344bd9b3 5694891 D2dac590 5694891