Spring Cloud Alibaba Seata 分布式事务解决方案
Spring Cloud Alibaba Seata 分布式事务解决方案
- 一、分布式事务问题
- 二、Seata简介
- 三、Seata的部署
-
- 3.1 Seata Server端配置
-
- 3.1.1 修改配置文件
- 3.1.2 MySQL 数据库配置
- 3.1.3 启动Seata Server端
- 3.2 Seata Client 客户端配置
-
- 3.2.1 业务前置准备
- 3.2.2 创建undo_log表
- 3.2.3 Seata Client配置文件
- 3.2.4 pom.xml文件
- 3.2.5 application.yml文件
- 3.2.6 业务代码编写：加@GlobalTransactional
- 3.2.7 config代码编写
- 3.2.8 主启动类
- 3.3 测试
一、分布式事务问题
- 一次业务操作需要跨多个数据源或者需要跨多个系统进行远程调用，就会产生分布式事务问题。
举例：
用户购买商品的业务逻辑。整个业务逻辑由3个微服务提供支持：
- 仓储服务：对给定的商品扣除仓储数量。
- 订单服务：根据采购需求创建订单。
- 帐户服务：从用户帐户中扣除余额。
单体应用被拆分成微服务应用，原来的三个模块被拆分成三个独立的应用，分别使用三个独立的数据源，业务操作需要调用三个服务来完成。此时每个服务内部的数据一致性由本地事务来保证，但是全局数据一致性问题是无法保证的。
二、Seata简介
Seata官网地址：http://seata.io/zh-cn/
- Seata是一款开源的分布式事务解决方案，致力于在微服务架构下提供高性能和简单易用的分布式事务服务。Seata 将为用户提供了 AT、TCC、SAGA 和 XA 事务模式，为用户打造一站式的分布式解决方案。
Seata术语：
-
TC (Transaction Coordinator) - 事务协调者
维护全局和分支事务的状态，驱动全局事务提交或回滚。 -
TM (Transaction Manager) - 事务管理器
定义全局事务的范围：开始全局事务、提交或回滚全局事务。 -
RM (Resource Manager) - 资源管理器
管理分支事务处理的资源，与TC交谈以注册分支事务和报告分支事务的状态，并驱动分支事务提交或回滚。
Seata处理过程：
- TM向TC申请开启一个全局事务，全局事务创建成功并生成一个全局唯一的XID；
- XID在微服务调用链路的上下文传播；
- RM向TC注册分支事务，将其纳入XID对应全局事务的管辖；
- TM向TC发起针对XID的全局提交或回滚决议；
- TC调度XID下管辖的全部分支事务完成提交或者回滚请求
三、Seata的部署
Seata的版本选择： Spring Cloud Alibaba与Spring Boot、Spring Cloud版本对应关系
官网版本说明
本次使用：Seata 1.2.0
3.1 Seata Server端配置
官方配置文档：Seata部署指南
下载seata-server-1.2.0和seata-1.2.0源码
- seate-server下载： https://seata.io/zh-cn/blog/download.html
- seata-1.2.0源码下载： https://github.com/seata/seata/releases
3.1.1 修改配置文件
解压后，进入 conf 目录开始参数的配置。我们修改 file.conf 和 registry.conf 这两个文件。
1、进入conf文件夹，修改file.conf文件
2、修改registry.conf文件
- 如果config设置成了file，则不需要网上的设置nacos的配置
3.1.2 MySQL 数据库配置
我们先创建数据库seata（数据库要与file.conf中db设置那里对应），数据库的建表语句在README文件的server连接中
让后执行mysql.sql
-- -------------------------------- The script used when storeMode is 'db' --------------------------------
-- the table to store GlobalSession data
CREATE TABLE IF NOT EXISTS `global_table`
(
`xid` VARCHAR(128) NOT NULL,
`transaction_id` BIGINT,
`status` TINYINT NOT NULL,
`application_id` VARCHAR(32),
`transaction_service_group` VARCHAR(32),
`transaction_name` VARCHAR(128),
`timeout` INT,
`begin_time` BIGINT,
`application_data` VARCHAR(2000),
`gmt_create` DATETIME,
`gmt_modified` DATETIME,
PRIMARY KEY (`xid`),
KEY `idx_gmt_modified_status` (`gmt_modified`, `status`),
KEY `idx_transaction_id` (`transaction_id`)
) ENGINE = InnoDB
DEFAULT CHARSET = utf8;
-- the table to store BranchSession data
CREATE TABLE IF NOT EXISTS `branch_table`
(
`branch_id` BIGINT NOT NULL,
`xid` VARCHAR(128) NOT NULL,
`transaction_id` BIGINT,
`resource_group_id` VARCHAR(32),
`resource_id` VARCHAR(256),
`branch_type` VARCHAR(8),
`status` TINYINT,
`client_id` VARCHAR(64),
`application_data` VARCHAR(2000),
`gmt_create` DATETIME(6),
`gmt_modified` DATETIME(6),
PRIMARY KEY (`branch_id`),
KEY `idx_xid` (`xid`)
) ENGINE = InnoDB
DEFAULT CHARSET = utf8;
-- the table to store lock data
CREATE TABLE IF NOT EXISTS `lock_table`
(
`row_key` VARCHAR(128) NOT NULL,
`xid` VARCHAR(96),
`transaction_id` BIGINT,
`branch_id` BIGINT NOT NULL,
`resource_id` VARCHAR(256),
`table_name` VARCHAR(32),
`pk` VARCHAR(36),
`gmt_create` DATETIME,
`gmt_modified` DATETIME,
PRIMARY KEY (`row_key`),
KEY `idx_branch_id` (`branch_id`)
) ENGINE = InnoDB
DEFAULT CHARSET = utf8;
3.1.3 启动Seata Server端
3.2 Seata Client 客户端配置
3.2.1 业务前置准备
业务场景：用户购买商品的业务逻辑。整个业务逻辑由3个微服务提供支持：
用户A购买商品，调用 A服务 创建订单完成，调用 B服务 扣减库存，然后调用 C服务 扣减账户余额。每个服务内部的数据一致性由本地事务来保证，多个服务调用来完成业务，全局事务数据一致性则由 Seata 来保证。
-
订单服务A：根据采购需求创建订单。
-
仓储服务B：对给定的商品扣除仓储数量。
-
帐户服务C：从用户帐户中扣除余额。
**业务数据库准备：**配置三个业务分别对应各自的数据库。
- A服务 对应数据库：seata_order ；表：t_order
- B服务 对应数据库：seata_storage ；表：t_storage
- C服务 对应数据库：seata_account ；表：t_account
建表语句：
# 创建seata_order数据库
CREATE DATABASE seata_order;
# 创建t_order表
CREATE TABLE seata_order.t_order(
`id` BIGINT(11) NOT NULL AUTO_INCREMENT PRIMARY KEY,
`user_id` BIGINT(11) DEFAULT NULL COMMENT '用户id',
`product_id` BIGINT(11) DEFAULT NULL COMMENT '产品id',
`count` INT(11) DEFAULT NULL COMMENT '数量',
`money` DECIMAL(11,0) DEFAULT NULL COMMENT '金额',
`status` INT(1) DEFAULT NULL COMMENT '订单状态：0：创建中; 1：已完结'
) ENGINE=INNODB AUTO_INCREMENT=7 DEFAULT CHARSET=utf8;
# 创建seata_storage数据库
CREATE DATABASE seata_storage;
# 创建t_storage表
CREATE TABLE seata_storage.t_storage(
`id` BIGINT(11) NOT NULL AUTO_INCREMENT PRIMARY KEY,
`product_id` BIGINT(11) DEFAULT NULL COMMENT '产品id',
`total` INT(11) DEFAULT NULL COMMENT '总库存',
`used` INT(11) DEFAULT NULL COMMENT '已用库存',
`residue` INT(11) DEFAULT NULL COMMENT '剩余库存'
) ENGINE=INNODB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;
# 插入一条数据
INSERT INTO seata_storage.t_storage(`id`,`product_id`,`total`,`used`,`residue`)
VALUES('1','1','100','0','100');
# 创建seata_account数据库
CREATE DATABASE seata_account;
# 创建t_account表
CREATE TABLE seata_account.t_account(
`id` BIGINT(11) NOT NULL AUTO_INCREMENT PRIMARY KEY COMMENT 'id',
`user_id` BIGINT(11) DEFAULT NULL COMMENT '用户id',
`total` DECIMAL(10,0) DEFAULT NULL COMMENT '总额度',
`used` DECIMAL(10,0) DEFAULT NULL COMMENT '已用余额',
`residue` DECIMAL(10,0) DEFAULT '0' COMMENT '剩余可用额度'
) ENGINE=INNODB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;
# 插入一条数据
INSERT INTO seata_account.t_account(`id`,`user_id`,`total`,`used`,`residue`) VALUES('1','1','1000','0','1000');
3.2.2 创建undo_log表
按照上述3库分别建对应的回滚日志表，建表文件在README_ZH文件中的client中
undo_log表建表语句如下：
-- for AT mode you must to init this sql for you business database. the seata server not need it.
CREATE TABLE IF NOT EXISTS `undo_log`
(
`id` BIGINT(20) NOT NULL AUTO_INCREMENT COMMENT 'increment id',
`branch_id` BIGINT(20) NOT NULL COMMENT 'branch transaction id',
`xid` VARCHAR(100) NOT NULL COMMENT 'global transaction id',
`context` VARCHAR(128) NOT NULL COMMENT 'undo_log context,such as serialization',
`rollback_info` LONGBLOB NOT NULL COMMENT 'rollback info',
`log_status` INT(11) NOT NULL COMMENT '0:normal status,1:defense status',
`log_created` DATETIME NOT NULL COMMENT 'create datetime',
`log_modified` DATETIME NOT NULL COMMENT 'modify datetime',
PRIMARY KEY (`id`),
UNIQUE KEY `ux_undo_log` (`xid`, `branch_id`)
) ENGINE = InnoDB
AUTO_INCREMENT = 1
DEFAULT CHARSET = utf8 COMMENT ='AT transaction mode undo table';
完成图示：
以下配置以
seata-order-service2001为例
项目结构：
3.2.3 Seata Client配置文件
配置文件的编写参考README_ZH文件中的client中：
1、file.conf，修改这一处
transport {
# tcp, unix-domain-socket
type = "TCP"
#NIO, NATIVE
server = "NIO"
#enable heartbeat
heartbeat = true
# the tm client batch send request enable
enableTmClientBatchSendRequest = false
# the rm client batch send request enable
enableRmClientBatchSendRequest = true
# the rm client rpc request timeout
rpcRmRequestTimeout = 2000
# the tm client rpc request timeout
rpcTmRequestTimeout = 10000
# the tc client rpc request timeout
rpcTcRequestTimeout = 5000
#thread factory for netty
threadFactory {
bossThreadPrefix = "NettyBoss"
workerThreadPrefix = "NettyServerNIOWorker"
serverExecutorThread-prefix = "NettyServerBizHandler"
shareBossWorker = false
clientSelectorThreadPrefix = "NettyClientSelector"
clientSelectorThreadSize = 1
clientWorkerThreadPrefix = "NettyClientWorkerThread"
# netty boss thread size
bossThreadSize = 1
#auto default pin or 8
workerThreadSize = "default"
}
shutdown {
# when destroy server, wait seconds
wait = 3
}
serialization = "seata"
compressor = "none"
}
service {
#transaction service group mapping
vgroupMapping.my_test_tx_group = "default"
#only support when registry.type=file, please don't set multiple addresses
default.grouplist = "127.0.0.1:8091"
#degrade, current not support
enableDegrade = false
#disable seata
disableGlobalTransaction = false
}
client {
rm {
asyncCommitBufferLimit = 10000
lock {
retryInterval = 10
retryTimes = 30
retryPolicyBranchRollbackOnConflict = true
}
reportRetryCount = 5
tableMetaCheckEnable = false
tableMetaCheckerInterval = 60000
reportSuccessEnable = false
sagaBranchRegisterEnable = false
sagaJsonParser = "fastjson"
sagaRetryPersistModeUpdate = false
sagaCompensatePersistModeUpdate = false
tccActionInterceptorOrder = -2147482648 #Ordered.HIGHEST_PRECEDENCE + 1000
}
tm {
commitRetryCount = 5
rollbackRetryCount = 5
defaultGlobalTransactionTimeout = 60000
degradeCheck = false
degradeCheckPeriod = 2000
degradeCheckAllowTimes = 10
interceptorOrder = -2147482648 #Ordered.HIGHEST_PRECEDENCE + 1000
}
undo {
dataValidation = true
onlyCareUpdateColumns = true
logSerialization = "jackson"
logTable = "undo_log"
compress {
enable = true
# allow zip, gzip, deflater, 7z, lz4, bzip2, zstd default is zip
type = zip
# if rollback info size > threshold, then will be compress
# allow k m g t
threshold = 64k
}
}
loadBalance {
type = "RandomLoadBalance"
virtualNodes = 10
}
}
log {
exceptionRate = 100
}
tcc {
fence {
# tcc fence log table name
logTableName = tcc_fence_log
# tcc fence log clean period
cleanPeriod = 1h
}
}
2、registry.conf，修改这一处
registry {
# file 、nacos 、eureka、redis、zk、consul、etcd3、sofa、custom
type = "nacos"
nacos {
application = "seata-server"
serverAddr = "127.0.0.1:8848"
namespace = ""
username = ""
password = ""
##if use MSE Nacos with auth, mutex with username/password attribute
#accessKey = ""
#secretKey = ""
}
eureka {
serviceUrl = "http://localhost:8761/eureka"
weight = "1"
}
redis {
serverAddr = "localhost:6379"
db = "0"
password = ""
timeout = "0"
}
zk {
serverAddr = "127.0.0.1:2181"
sessionTimeout = 6000
connectTimeout = 2000
username = ""
password = ""
}
consul {
serverAddr = "127.0.0.1:8500"
aclToken = ""
}
etcd3 {
serverAddr = "http://localhost:2379"
}
sofa {
serverAddr = "127.0.0.1:9603"
region = "DEFAULT_ZONE"
datacenter = "DefaultDataCenter"
group = "SEATA_GROUP"
addressWaitTime = "3000"
}
file {
name = "file.conf"
}
custom {
name = ""
}
}
config {
# file、nacos 、apollo、zk、consul、etcd3、springCloudConfig、custom
type = "file"
nacos {
serverAddr = "127.0.0.1:8848"
namespace = ""
group = "SEATA_GROUP"
username = ""
password = ""
##if use MSE Nacos with auth, mutex with username/password attribute
#accessKey = ""
#secretKey = ""
dataId = "seata.properties"
}
consul {
serverAddr = "127.0.0.1:8500"
key = "seata.properties"
aclToken = ""
}
apollo {
appId = "seata-server"
apolloMeta = "http://192.168.1.204:8801"
namespace = "application"
apolloAccesskeySecret = ""
}
zk {
serverAddr = "127.0.0.1:2181"
sessionTimeout = 6000
connectTimeout = 2000
username = ""
password = ""
nodePath = "/seata/seata.properties"
}
etcd3 {
serverAddr = "http://localhost:2379"
key = "seata.properties"
}
file {
name = "file.conf"
}
custom {
name = ""
}
}
3.2.4 pom.xml文件
<dependencies>
<dependency>
<groupId>com.alibaba.cloudgroupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discoveryartifactId>
dependency>
<dependency>
<groupId>com.alibaba.cloudgroupId>
<artifactId>spring-cloud-starter-alibaba-seataartifactId>
<exclusions>
<exclusion>
<artifactId>seata-allartifactId>
<groupId>io.seatagroupId>
exclusion>
exclusions>
dependency>
<dependency>
<groupId>io.seatagroupId>
<artifactId>seata-allartifactId>
<version>1.2.0version>
dependency>
<dependency>
<groupId>org.springframework.cloudgroupId>
<artifactId>spring-cloud-starter-openfeignartifactId>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-webartifactId>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-actuatorartifactId>
dependency>
<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
<version>5.1.37version>
dependency>
<dependency>
<groupId>com.alibabagroupId>
<artifactId>druid-spring-boot-starterartifactId>
<version>1.1.10version>
dependency>
<dependency>
<groupId>org.mybatis.spring.bootgroupId>
<artifactId>mybatis-spring-boot-starterartifactId>
<version>2.0.0version>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-testartifactId>
<scope>testscope>
dependency>
<dependency>
<groupId>org.projectlombokgroupId>
<artifactId>lombokartifactId>
<optional>trueoptional>
dependency>
dependencies>
3.2.5 application.yml文件
server:
port: 2001
spring:
application:
name: seata-order-service
cloud:
alibaba:
seata:
# 自定义事务组名称需要与seata-server中的对应
tx-service-group: my_test_tx_group #因为seata的file.conf文件中没有service模块，事务组名默认为my_test_tx_group
#service要与tx-service-group对齐，vgroupMapping和grouplist在service的下一级，my_test_tx_group在再下一级
service:
vgroupMapping:
#要和tx-service-group的值一致
my_test_tx_group: default
grouplist:
# seata seaver的 地址配置，此处可以集群配置是个数组
default: 127.0.0.1:8091
nacos:
discovery:
server-addr: localhost:8848
datasource:
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost:3306/seata_order?useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=GMT%2B8
username: root
password: root
feign:
hystrix:
enabled: false
logging:
level:
io:
seata:
mybatis:
mapperLocations: classpath:mapper/*.xml
3.2.6 业务代码编写：加@GlobalTransactional
dao层、mapper层、controller层代码省略
业务代码使用OpenFeign 的方式进行服务间的调用，来实现一个简单的业务功能。AT模式只用一个 @GlobalTransactional 注解即可实现分布式事务。name 属性为事务唯一性表示，可以随意定义。rollbackFor 属性为指定Exception异常才进行事务回滚。
OrderServiceImpl.java
@Service
@Slf4j
public class OrderServiceImpl implements OrderService {
@Resource
private OrderDao orderDao;
@Resource
private StorageService storageService;
@Resource
private AccountService accountService;
/**
* 创建订单->调用库存服务扣减库存->调用账户服务扣减账户余额->修改订单状态
* 简单说：
* 下订单->减库存->减余额->改状态
*/
@Override
@GlobalTransactional(name = "fsp-create-order",rollbackFor = Exception.class)
public void create(Order order) {
log.info("------->下单开始");
//本应用创建订单
orderDao.create(order);
//远程调用库存服务扣减库存
log.info("------->order-service中扣减库存开始");
storageService.decrease(order.getProductId(),order.getCount());
log.info("------->order-service中扣减库存结束");
//远程调用账户服务扣减余额
log.info("------->order-service中扣减余额开始");
accountService.decrease(order.getUserId(),order.getMoney());
log.info("------->order-service中扣减余额结束");
//修改订单状态为已完成
log.info("------->order-service中修改订单状态开始");
orderDao.update(order.getUserId(),0);
log.info("------->order-service中修改订单状态结束");
log.info("------->下单结束");
}
}
3.2.7 config代码编写
1、MybatisConfig.java
@Configuration
@MapperScan({"com.zb.springcloud.dao"})
public class MyBatisConfig {
}
2、DataSourceProxyConfig.java
package com.zb.springcloud.config;
import com.alibaba.druid.pool.DruidDataSource;
import io.seata.rm.datasource.DataSourceProxy;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.transaction.SpringManagedTransactionFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import javax.sql.DataSource;
@Configuration
public class DataSourceProxyConfig {
@Value("${mybatis.mapperLocations}")
private String mapperLocations;
@Bean
@ConfigurationProperties(prefix = "spring.datasource")
public DataSource druidDataSource(){
return new DruidDataSource();
}
@Bean
public DataSourceProxy dataSourceProxy(DataSource dataSource) {
return new DataSourceProxy(dataSource);
}
@Bean
public SqlSessionFactory sqlSessionFactoryBean(DataSourceProxy dataSourceProxy) throws Exception {
SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
sqlSessionFactoryBean.setDataSource(dataSourceProxy);
sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources(mapperLocations));
sqlSessionFactoryBean.setTransactionFactory(new SpringManagedTransactionFactory());
return sqlSessionFactoryBean.getObject();
}
}
3.2.8 主启动类
@EnableDiscoveryClient
@EnableFeignClients
@SpringBootApplication(exclude = DataSourceAutoConfiguration.class)//取消数据源的自动创建
public class SeataOrderMainApp2001 {
public static void main(String[] args)
{
SpringApplication.run(SeataOrderMainApp2001.class, args);
}
}
3.3 测试
-
分别启三个服务，可以看到在项目启动过程中，Seata Sever 服务端会有相对应提示
发送请求 http://localhost:2001/order/create?userId=1&productId=1&count=10&money=100 来模拟下单请求。发送多次请求，可以看到下单都成功了，Seata Server 端也有事务在进行处理的过程。（此时数据库中，因为事务处理完成，并没有任何数据）
参考博客：
Spring Cloud Alibaba Seata 分布式事务解决方案简介
SpringCloud 整合Seata 解决分布式事务