spring boot 分布式事务解决方案LCN

对比LCN和saga(华为apache孵化器项目) ，LCN使用代理连接池封装补偿方法，saga需要手工写补偿方法，相对来说LCN使用更加方便。

参考官方地址：

https://github.com/codingapi/tx-lcn/wiki/TxManager%E5%90%AF%E5%8A%A8%E8%AF%B4%E6%98%8E

1.    原理

1.     事务控制原理

LCN事务控制原理是由事务模块TxClient下的代理连接池与TxManager的协调配合完成的事务协调控制。

TxClient的代理连接池实现了javax.sql.DataSource接口，并重写了close方法，事务模块在提交关闭以后TxClient连接池将执行"假关闭"操作，等待TxManager协调完成事务以后在关闭连接。

2.     调用时序图

1.     正常

2.     异常

2.    服务端

tx-manager 4.1.0

3.    客户端

1.     pom添加依赖

<properties>         <lcn.last.version>4.1.0lcn.last.version>     properties>

<dependency>             <groupId>org.mybatis.spring.bootgroupId>             <artifactId>mybatis-spring-boot-starterartifactId>             <version>1.1.1version>         dependency>         <dependency>             <groupId>com.codingapigroupId>             <artifactId>transaction-springcloudartifactId>             <version>${lcn.last.version}version>             <exclusions>                 <exclusion>                    <groupId>org.slf4jgroupId>                    <artifactId>*artifactId>                 exclusion>             exclusions>         dependency>         <dependency>             <groupId>com.codingapigroupId>             <artifactId>tx-plugins-dbartifactId>             <version>${lcn.last.version}version>             <exclusions>                 <exclusion>                    <groupId>org.slf4jgroupId>                    <artifactId>*artifactId>                 exclusion>             exclusions>         dependency>

2.    配置文件

#Ribbon的负载均衡策略：随机 #ribbon.NFLoadBalancerRuleClassName=com.netflix.loadbalancer.RandomRule #由于springcloud默认是开启的重试机制，开启次机制以后会导致当springcloud请求超时时会重复调用业务模块，从而会引发数据混乱，因此建议将其禁用。对于网络模块超时等故障问题建议使用hytrix方式。 #ribbon.MaxAutoRetriesNextServer=0   tm:   manager:     url: http://localhost:8899/tx/manager/ ribbon:   NFLoadBalancerRuleClassName: com.netflix.loadbalancer.RandomRule   MaxAutoRetriesNextServer: 0 init-db:true hystrix:   command:     default:       execution:         isolation:           thread:             timeoutInMilliseconds: 6000

 

3.     Service包下处理http请求和对服务器的连接

package com.svw.tbox.tcloud.commons.ms.service;   import com.codingapi.tx.netty.service.TxManagerHttpRequestService; import com.lorne.core.framework.utils.http.HttpUtils; import org.springframework.stereotype.Service;   @Service publicclass TxManagerHttpRequestServiceImpl implements TxManagerHttpRequestService{       @Override     public String httpGet(String url) {     //GET请求前         String res = HttpUtils.get(url);         //GET请求后         returnres;     }       @Override     public String httpPost(String url, String params) {     //POST请求前         String res = HttpUtils.post(url,params);         //POST请求后         returnres;     } }

package com.svw.tbox.tcloud.commons.ms.service;   import com.codingapi.tx.config.service.TxManagerTxUrlService; import org.springframework.beans.factory.annotation.Value; import org.springframework.stereotype.Service;   @Service public class TxManagerTxUrlServiceImpl implements TxManagerTxUrlService{       @Value("${tm.manager.url}")     private String url;       @Override     public String getTxUrl() {     //load tm.manager.url         return url;     } }

 

4.    启动类配置代理连接池

import javax.sql.DataSource; import org.mybatis.spring.annotation.MapperScan; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cloud.client.discovery.EnableDiscoveryClient; import org.springframework.cloud.netflix.hystrix.EnableHystrix; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.ComponentScan; import org.springframework.core.env.Environment; import com.alibaba.druid.pool.DruidDataSource;   @SpringBootApplication @EnableDiscoveryClient @EnableHystrix @MapperScan(basePackages = "com.svw.tbox.tcloud.commons.ms.dao") @ComponentScan(basePackages = { "com.svw.tbox.tcloud" }) publicclass MsApplication {     …… @Autowired     private Environment env;       @Bean     public DataSource dataSource() {         DruidDataSource dataSource = new DruidDataSource();         dataSource.setUrl(env.getProperty("spring.datasource.url"));         dataSource.setUsername(env.getProperty("spring.datasource.username"));//用户名         dataSource.setPassword(env.getProperty("spring.datasource.password"));//密码         dataSource.setInitialSize(2);         dataSource.setMaxActive(20);         dataSource.setMinIdle(0);         dataSource.setMaxWait(60000);         dataSource.setValidationQuery("SELECT 1");         dataSource.setTestOnBorrow(false);         dataSource.setTestWhileIdle(true);         dataSource.setPoolPreparedStatements(false);         returndataSource;     }

 

5.    测试代码

调用方tcloud-mds => 参与方tcloud-commons

1.     调用方：tcloud-mds

package com.svw.tbox.tcloud.commons.api.feign;   import org.springframework.cloud.netflix.feign.FeignClient; import com.svw.tbox.tcloud.commons.api.config.TxFeignConfiguration; import com.svw.tbox.tcloud.commons.api.service.SysErrorCodeMappingService;   /**  * ClassName: SysErrorCodeMappingFeign  * Description: 远程调用错误码服务  * Author: hurf  * Date: 2017年12月11日  */ @FeignClient(value = "tcloud-commons-ms") publicinterface SysErrorCodeMappingFeign extends SysErrorCodeMappingService { }

 

2.     事务发起@TxTransaction(isStart=true)

import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import org.springframework.transaction.annotation.Transactional;   import com.codingapi.tx.annotation.TxTransaction; import com.svw.tbox.tcloud.commons.api.entity.SysErrorCodeMapping; import com.svw.tbox.tcloud.commons.api.feign.SysErrorCodeMappingFeign; import com.svw.tbox.tcloud.commons.api.service.CmnService; import com.svw.tbox.tcloud.commons.api.service.JedisTemplate; import com.svw.tbox.tcloud.commons.util.DateUtil; import com.svw.tbox.tcloud.mds.entity.ThUserLogin;   /**  * @Title ClassName: UserTokenService  * @Description Description: 登录服务  * @Author Author: hurf  * @Date Date: 2018年2月6日  */ @Service publicclass UserTokenService extends CmnService{     @Autowired     private JedisTemplate jedisTemplate;         @Autowired     private SysErrorCodeMappingFeign sysErrorCodeMappingFeign;         @Transactional     @TxTransaction(isStart=true)     public String add(SysErrorCodeMapping sysErrorCodeMapping) {         // 远程调用新增         sysErrorCodeMappingFeign.add(sysErrorCodeMapping);         // 本地新增db         insertSelective(ThUserLogin.builder().accessToken(sysErrorCodeMapping.getApiCode())                 .refreshToken(sysErrorCodeMapping.getInnerErrorCode()).createBy("测试事务").build());         //本地缓存事务         jedisTemplate.set("isStart", DateUtil.getNow()); //      int ii = 1/0;//异常                 return"测试分布式事务成功";     } }

 

3.     事务参与方tcloud-commons-ms: @Transactional

@RestController publicclass SysErrorCodeMappingController implements SysErrorCodeMappingService {       @Autowired     private MsService msService;       @ApiOperation("添加错误码信息")     @Override     public SystemResponse add(@RequestBody SysErrorCodeMapping sysErrorCodeMapping) {         returnmsService.add(sysErrorCodeMapping);     }     。。。。。。

importcom.codingapi.tx.annotation.ITxTransaction;   @Service @CacheConfig(cacheNames = "sys-code-resource") publicclass MsService implements ITxTransaction{       @Autowired     private JedisTemplate jedisTemplate;       @Autowired     private SysErrorCodeMappingMapper sysErrorCodeMappingMapper;     /**      * Title: 事务参与方      * Description:      * @param sysErrorCodeMapping      * @return      */     @Transactional     public SystemResponse add(SysErrorCodeMapping sysErrorCodeMapping) {         //db操作         sysErrorCodeMapping.setVersion(1);         sysErrorCodeMapping.setDelFlag(Short.valueOf("0"));         sysErrorCodeMapping.setCreatedBy("admin");         sysErrorCodeMapping.setCreateDate(new Date());         sysErrorCodeMappingMapper.insertSelective(sysErrorCodeMapping);                 //redis操作         jedisTemplate.set("addTest"+DateUtil.getNow(),"tttttttttttttttttttttt");         return ResultUtil.success(refreshAll());     }

6.     效果

启动两个微服务，访问调用方接口

1.     正常情况

2.     异常回滚情况

删除刚刚的测试数据，开启异常情况：

@Transactional     @TxTransaction(isStart=true)     public String add(SysErrorCodeMapping sysErrorCodeMapping) {         // 远程调用新增         sysErrorCodeMappingFeign.add(sysErrorCodeMapping);         // 本地新增db         insertSelective(ThUserLogin.builder().accessToken(sysErrorCodeMapping.getApiCode())                 .refreshToken(sysErrorCodeMapping.getInnerErrorCode()).createBy("测试事务").build());         //本地缓存事务         jedisTemplate.set("isStart", DateUtil.getNow());         intii = 1/0;//异常                 return"测试分布式事务成功";     }

 

发现mysql已经回滚了，但是redis没有回滚 =》 目前只支持db分布式事务。