Seata解决分布式事务
简介
Seata 是阿里开源的一款开源的分布式事务解决方案，致力于提供高性能和简单易用的分布式事务服务。
初始化数据库
创建 seata 库，初始化脚本如下
-- -------------------------------- 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;
使用docker安装
docker pull seataio/seata-server:1.5.0
docker run -d --name seata-server -p 8091:8091 -p 7091:7091 seataio/seata-server:1.5.0
修改配置文件
docker exec -it seata-server sh #不能使用 /bin/bash
docker cp seata-server:/seata-server/resources/application.yml .
docker cp seata-server:/seata-server/resources/application.example.yml .
默认的配置文件 application.yml 内容如下
server:
port: 7091
spring:
application:
name: seata-server
logging:
config: classpath:logback-spring.xml
file:
path: ${user.home}/logs/seata
extend:
logstash-appender:
destination: 127.0.0.1:4560
kafka-appender:
bootstrap-servers: 127.0.0.1:9092
topic: logback_to_logstash
console:
user:
username: seata
password: seata
seata:
config:
# support: nacos, consul, apollo, zk, etcd3
type: file
registry:
# support: nacos, eureka, redis, zk, consul, etcd3, sofa
type: file
store:
# support: file 、 db 、 redis
mode: file
# server:
# service-port: 8091 #If not configured, the default is '${server.port} + 1000'
security:
secretKey: SeataSecretKey0c382ef121d778043159209298fd40bf3850a017
tokenValidityInMilliseconds: 1800000
ignore:
urls: /,/**/*.css,/**/*.js,/**/*.html,/**/*.map,/**/*.svg,/**/*.png,/**/*.ico,/console-fe/public/**,/api/v1/auth/login#
参考 application.example.yml，修改之后为
server:
port: 7091
spring:
application:
name: seata-server
logging:
config: classpath:logback-spring.xml
file:
path: ${user.home}/logs/seata
extend:
logstash-appender:
destination: 127.0.0.1:4560
kafka-appender:
bootstrap-servers: 127.0.0.1:9092
topic: logback_to_logstash
console:
user:
username: seata
password: seata
seata:
config:
type: nacos
nacos:
server-addr: ip:8848
namespace: d8b0df04-aa58-4a5b-b582-7d133b9e8b2c
group: SEATA_GROUP
username: nacos
password: nacos
data-id: seataServer.properties
registry:
type: nacos
nacos:
application: seata-server
server-addr: ip:8848
group: SEATA_GROUP
namespace: d8b0df04-aa58-4a5b-b582-7d133b9e8b2c
cluster: default
username: nacos
password: nacos
store:
mode: db
db:
datasource: druid
db-type: mysql
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://ip:port/seata?rewriteBatchedStatements=true&serverTimezone=UTC
user: root
password: xxx
min-conn: 5
max-conn: 100
global-table: global_table
branch-table: branch_table
lock-table: lock_table
distributed-lock-table: distributed_lock
query-limit: 100
max-wait: 5000
security:
secretKey: SeataSecretKey0c382ef121d778043159209298fd40bf3850a017
tokenValidityInMilliseconds: 1800000
ignore:
urls: /,/**/*.css,/**/*.js,/**/*.html,/**/*.map,/**/*.svg,/**/*.png,/**/*.ico,/console-fe/public/**,/api/v1/auth/login#
使用nacos当做配置中心和注册中心，使用数据库存储。配置MySQL8.0所需要的jar
wget https://repo1.maven.org/maven2/mysql/mysql-connector-java/8.0.19/mysql-connector-java-8.0.19.jar
docker cp application.yml seata-server:/seata-server/resources/
docker cp mysql-connector-java-8.0.19.jar seata-server:/seata-server/libs/
docker restart seata-server
查看nacos服务列表，可以看到seata-server服务，说明启动成功。
SpringBoot多项目使用seata(HttpClient调用)
参与分布式的数据库要创建 undo_log 表
CREATE TABLE undo_log
(
id BIGINT(20) NOT NULL AUTO_INCREMENT,
branch_id BIGINT(20) NOT NULL,
xid VARCHAR(100) NOT NULL,
context VARCHAR(128) NOT NULL,
rollback_info LONGBLOB NOT NULL,
log_status INT(11) NOT NULL,
log_created DATETIME NOT NULL,
log_modified DATETIME NOT NULL,
PRIMARY KEY (id),
UNIQUE KEY ux_undo_log (xid, branch_id)
) ENGINE = InnoDB AUTO_INCREMENT = 1 DEFAULT CHARSET = utf8;
业务使用表如下
create table if not exists tb_order
(
id bigint auto_increment primary key comment '主键',
product_id bigint comment '商品id',
quantity int comment '购买数量',
price decimal(10, 2) comment '总金额'
);
create table if not exists tb_product
(
id bigint auto_increment primary key comment '主键',
name varchar(20) comment '商品名称',
stock int comment '库存量'
);
insert into tb_product(name, stock)
values ('小米手机', 100);
一个订单表，一个商品表，订单服务创建订单的过程中会调用商品服务来减库存，调用过程中会将全局事务id传递过去。
- 商品服务成功，订单成功，事务成功
- 商品服务失败，订单也失败，事务失败
- 商品服务成功，订单失败，事务回滚
项目代码
order 服务
配置 seata 地址
seata:
application-id: ${spring.application.name} # Seata 应用编号，默认为 ${spring.application.name}
tx-service-group: ${spring.application.name}-group # Seata 事务组编号，用于 TC 集群名
# 服务配置项，对应 ServiceProperties 类
service:
# 虚拟组和分组的映射
vgroup-mapping:
spring-seata-order-group: default
# 分组和 Seata 服务的映射
grouplist:
default: ip:8091
enabled: false
spring:
application:
name: spring-seata-order
datasource:
url: jdbc:mysql://ip:port/testdb?characterEncoding=utf8&useSSL=true&serverTimezone=Asia/Shanghai
username: root
password: xxx
driver-class-name: com.mysql.cj.jdbc.Driver
hikari:
max-lifetime: 30000
cloud:
nacos:
discovery:
namespace: d8b0df04-aa58-4a5b-b582-7d133b9e8b2c
username: nacos
password: nacos
server-addr: ip:8848
服务调用，底层通过 nacos 做负载均衡
String resp = restTemplate.postForObject("http://spring-seata-product/api/v1/product/reduceProductStock", null, String.class);
通过拦截器，将 seata 的分布式事物 id 传递到其他服务，seata 内的 TransactionPropagationInterceptor 拦截器获取到此 id 并保存到 RootContext 中。
@Component
public class RestTemplateBeanPostProcessor implements BeanPostProcessor {
@Override
public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
if (bean instanceof RestTemplate) {
((RestTemplate) bean).getInterceptors()
.add((request, body, execution) -> {
String xid = RootContext.getXID();
if (Objects.nonNull(xid)) {
request.getHeaders().add(RootContext.KEY_XID, xid);
}
return execution.execute(request, body);
});
}
return bean;
}
}
product 服务
配置 seata 地址
seata:
application-id: ${spring.application.name} # Seata 应用编号，默认为 ${spring.application.name}
tx-service-group: ${spring.application.name}-group # Seata 事务组编号，用于 TC 集群名
# 服务配置项，对应 ServiceProperties 类
service:
# 虚拟组和分组的映射
vgroup-mapping:
spring-seata-order-group: default
# 分组和 Seata 服务的映射
grouplist:
default: ip:8091
enabled: false
spring:
application:
name: spring-seata-product
datasource:
url: jdbc:mysql://ip:port/testdb?characterEncoding=utf8&useSSL=true&serverTimezone=Asia/Shanghai
username: root
password: xxx
driver-class-name: com.mysql.cj.jdbc.Driver
hikari:
max-lifetime: 30000
cloud:
nacos:
discovery:
namespace: d8b0df04-aa58-4a5b-b582-7d133b9e8b2c
username: nacos
password: nacos
server-addr: ip:8848
参考
Seata快速入门-官方文档
使用 Docker 部署 Seata Server (1.5.0)
芋道 Spring Boot 分布式事务 Seata 入门
