Seata AT TM-＞RC-＞RM一次完整的交互过程

原理

TM两阶段：

阶段1：TM向TC申请全局事务，netty客户端发起了一次记录xid的请求

阶段2：TC协调之后，决定执行RM是否提交或者回滚。

spring公共组件部分

1、SeataAutoConfiguration类加载

利用springboot自动装配机制从spring.factories文件加载自动配置类SeataAutoConfiguration

org.springframework.boot.autoconfigure.EnableAutoConfiguration=io.seata.spring.boot.autoconfigure.SeataAutoConfiguration

@ConditionalOnProperty(prefix = SEATA_PREFIX, name = "enabled", havingValue = "true", matchIfMissing = true)
@AutoConfigureAfter({SeataCoreAutoConfiguration.class})
public class SeataAutoConfiguration {
    private static final Logger LOGGER = LoggerFactory.getLogger(SeataAutoConfiguration.class);

    @Bean(BEAN_NAME_FAILURE_HANDLER)
    @ConditionalOnMissingBean(FailureHandler.class)
    public FailureHandler failureHandler() {
        return new DefaultFailureHandlerImpl();
    }

    @Bean
    @DependsOn({BEAN_NAME_SPRING_APPLICATION_CONTEXT_PROVIDER, BEAN_NAME_FAILURE_HANDLER})
    @ConditionalOnMissingBean(GlobalTransactionScanner.class)
    public GlobalTransactionScanner globalTransactionScanner(SeataProperties seataProperties, FailureHandler failureHandler,
            ConfigurableListableBeanFactory beanFactory,
            @Autowired(required = false) List<ScannerChecker> scannerCheckers) {
        if (LOGGER.isInfoEnabled()) {
            LOGGER.info("Automatically configure Seata");
        }

        // set bean factory
        GlobalTransactionScanner.setBeanFactory(beanFactory);

        // add checkers
        // '/META-INF/services/io.seata.spring.annotation.ScannerChecker'
        GlobalTransactionScanner.addScannerCheckers(EnhancedServiceLoader.loadAll(ScannerChecker.class));
        // spring beans
        GlobalTransactionScanner.addScannerCheckers(scannerCheckers);

        // add scannable packages
        GlobalTransactionScanner.addScannablePackages(seataProperties.getScanPackages());
        // add excludeBeanNames
        GlobalTransactionScanner.addScannerExcludeBeanNames(seataProperties.getExcludesForScanning());

        // create global transaction scanner
        return new GlobalTransactionScanner(seataProperties.getApplicationId(), seataProperties.getTxServiceGroup(), failureHandler);
    }
}