TCC细读

重试定时任务，通过外部调度实现

package org.mengyun.tcctransaction.spring.recover;

import org.mengyun.tcctransaction.SystemException;
import org.mengyun.tcctransaction.recover.TransactionRecovery;
import org.mengyun.tcctransaction.support.TransactionConfigurator;
import org.quartz.Scheduler;
import org.springframework.scheduling.quartz.CronTriggerFactoryBean;
import org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean;

/**
 * Created by changming.xie on 6/2/16.
 */
public class RecoverScheduledJob {

    private TransactionRecovery transactionRecovery;

    private TransactionConfigurator transactionConfigurator;

    private Scheduler scheduler;

    public void init() {
        try {
            MethodInvokingJobDetailFactoryBean jobDetail = new MethodInvokingJobDetailFactoryBean();
            jobDetail.setTargetObject(transactionRecovery);
            jobDetail.setTargetMethod("startRecover");
            jobDetail.setName("transactionRecoveryJob");
            jobDetail.setConcurrent(false);
            jobDetail.afterPropertiesSet();

            CronTriggerFactoryBean cronTrigger = new CronTriggerFactoryBean();
            cronTrigger.setBeanName("transactionRecoveryCronTrigger");
            cronTrigger.setCronExpression(transactionConfigurator.getRecoverConfig().getCronExpression());
            cronTrigger.setJobDetail(jobDetail.getObject());
            cronTrigger.afterPropertiesSet();
            scheduler.scheduleJob(jobDetail.getObject(), cronTrigger.getObject());
            scheduler.start();
        } catch (Exception e) {
            throw new SystemException(e);
        }
    }

    public void setTransactionRecovery(TransactionRecovery transactionRecovery) {
        this.transactionRecovery = transactionRecovery;
    }

    public Scheduler getScheduler() {
        return scheduler;
    }

    public void setScheduler(Scheduler scheduler) {
        this.scheduler = scheduler;
    }

    public void setTransactionConfigurator(TransactionConfigurator transactionConfigurator) {
        this.transactionConfigurator = transactionConfigurator;
    }
}

执行TransactionRecovery的startRecover方法，查找事物存储中，超过某一段设置时间一直没有修改的事物，执行恢复操作，更新或删除对应的状态和数据

package org.mengyun.tcctransaction.recover;

import com.alibaba.fastjson.JSON;
import org.apache.commons.lang3.exception.ExceptionUtils;
import org.apache.log4j.Logger;
import org.mengyun.tcctransaction.OptimisticLockException;
import org.mengyun.tcctransaction.Transaction;
import org.mengyun.tcctransaction.TransactionRepository;
import org.mengyun.tcctransaction.api.TransactionStatus;
import org.mengyun.tcctransaction.common.TransactionType;
import org.mengyun.tcctransaction.support.TransactionConfigurator;

import java.util.Calendar;
import java.util.Date;
import java.util.List;

/**
 * Created by changmingxie on 11/10/15.
 */
public class TransactionRecovery {

    static final Logger logger = Logger.getLogger(TransactionRecovery.class.getSimpleName());
    private TransactionConfigurator transactionConfigurator;

    public void startRecover() {
        List<Transaction> transactions = loadErrorTransactions();
        recoverErrorTransactions(transactions);
    }

    private List<Transaction> loadErrorTransactions() {
        long currentTimeInMillis = Calendar.getInstance().getTimeInMillis();
        TransactionRepository transactionRepository = transactionConfigurator.getTransactionRepository();
        RecoverConfig recoverConfig = transactionConfigurator.getRecoverConfig();
        return transactionRepository.findAllUnmodifiedSince(new Date(currentTimeInMillis - recoverConfig.getRecoverDuration() * 1000));
    }

    private void recoverErrorTransactions(List<Transaction> transactions) {
        for (Transaction transaction : transactions) {
            if (transaction.getRetriedCount() > transactionConfigurator.getRecoverConfig().getMaxRetryCount()) {
                logger.error(String.format("recover failed with max retry count,will not try again. txid:%s, status:%s,retried count:%d,transaction content:%s", transaction.getXid(), transaction.getStatus().getId(), transaction.getRetriedCount(), JSON.toJSONString(transaction)));
                continue;
            }

            if (transaction.getTransactionType().equals(TransactionType.BRANCH)
                    && (transaction.getCreateTime().getTime() +
                    transactionConfigurator.getRecoverConfig().getMaxRetryCount() *
                            transactionConfigurator.getRecoverConfig().getRecoverDuration() * 1000
                    > System.currentTimeMillis())) {
                continue;
            }
            
            try {
                transaction.addRetriedCount();
                if (transaction.getStatus().equals(TransactionStatus.CONFIRMING)) {
                    transaction.changeStatus(TransactionStatus.CONFIRMING);
                    transactionConfigurator.getTransactionRepository().update(transaction);
                    transaction.commit();
                    transactionConfigurator.getTransactionRepository().delete(transaction);
                } else if (transaction.getStatus().equals(TransactionStatus.CANCELLING)
                        || transaction.getTransactionType().equals(TransactionType.ROOT)) {
                    transaction.changeStatus(TransactionStatus.CANCELLING);
                    transactionConfigurator.getTransactionRepository().update(transaction);
                    transaction.rollback();
                    transactionConfigurator.getTransactionRepository().delete(transaction);
                }
            } catch (Throwable throwable) {
                if (throwable instanceof OptimisticLockException
                        || ExceptionUtils.getRootCause(throwable) instanceof OptimisticLockException) {
                    logger.warn(String.format("optimisticLockException happened while recover. txid:%s, status:%s,retried count:%d,transaction content:%s", transaction.getXid(), transaction.getStatus().getId(), transaction.getRetriedCount(), JSON.toJSONString(transaction)), throwable);
                } else {
                    logger.error(String.format("recover failed, txid:%s, status:%s,retried count:%d,transaction content:%s", transaction.getXid(), transaction.getStatus().getId(), transaction.getRetriedCount(), JSON.toJSONString(transaction)), throwable);
                }
            }
        }
    }

    public void setTransactionConfigurator(TransactionConfigurator transactionConfigurator) {
        this.transactionConfigurator = transactionConfigurator;
    }
}