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>4.1.0</lcn.last.version>

    </properties>

        <dependency>

            <groupId>org.mybatis.spring.boot</groupId>

            <artifactId>mybatis-spring-boot-starter</artifactId>

            <version>1.1.1</version>

        </dependency>

        <dependency>

            <groupId>com.codingapi</groupId>

            <artifactId>transaction-springcloud</artifactId>

            <version>${lcn.last.version}</version>

            <exclusions>

                <exclusion>

                   <groupId>org.slf4j</groupId>

                   <artifactId>*</artifactId>

                </exclusion>

            </exclusions>

        </dependency>

        <dependency>

            <groupId>com.codingapi</groupId>

            <artifactId>tx-plugins-db</artifactId>

            <version>${lcn.last.version}</version>

            <exclusions>

                <exclusion>

                   <groupId>org.slf4j</groupId>

                   <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;

 

/**

 * <p>ClassName: SysErrorCodeMappingFeign</p>

 * <p>Description: 远程调用错误码服务</p>

 * <p>Author: hurf</p>

 * <p>Date: 2017年12月11日</p>

 */

@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<p>ClassName: UserTokenService</p>

 * @Description<p>Description: 登录服务</p>

 * @Author<p>Author: hurf</p>

 * @Date<p>Date: 2018年2月6日</p>

 */

@Service

publicclass UserTokenService extends CmnService<ThUserLogin>{

    @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;

    /**

     * <p>Title: 事务参与方</p>

     * <p>Description: </p>

     * @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。