关于通过java调用datax,返回任务执行的方法

DATAX

DataX 是阿里巴巴集团内被广泛使用的离线数据同步工具/平台，实现包括 MySQL、Oracle、SqlServer、Postgre、HDFS、Hive、ADS、HBase、TableStore(OTS)、MaxCompute(ODPS)、DRDS 等各种异构数据源之间高效的数据同步功能。

datax的详细介绍

请参考 DataX-Introduction

引言

因为业务需要，需要使用到datax把数据从文本写入到数据库，原来的做法都是使用python通过datax.py去调用脚本，阿文为了能更好的管控datax的任务，阿文要求我们对datax进行改造，使用java集成的方式去调用datax，并返回任务执行的详细信息。

datax源码跟踪

从github下完源码开始改造，datax的启动类在datax-core包下Engine类的entry方法，该方法是一个静态方法。

public static void entry(final String[] args) throws Throwable {
Options options = new Options();
options.addOption("job", true, "Job config.");
options.addOption("jobid", true, "Job unique id.");
options.addOption("mode", true, "Job runtime mode.");

BasicParser parser = new BasicParser();
CommandLine cl = parser.parse(options, args);

String jobPath = cl.getOptionValue("job");

// 如果用户没有明确指定jobid, 则 datax.py 会指定 jobid 默认值为-1
String jobIdString = cl.getOptionValue("jobid");
RUNTIME_MODE = cl.getOptionValue("mode");

Configuration configuration = ConfigParser.parse(jobPath);

long jobId;
if (!"-1".equalsIgnoreCase(jobIdString)) {
 jobId = Long.parseLong(jobIdString);
} else {
 // only for dsc & ds & datax 3 update
 String dscJobUrlPatternString = "/instance/(\\d{1,})/config.xml";
 String dsJobUrlPatternString = "/inner/job/(\\d{1,})/config";
 String dsTaskGroupUrlPatternString = "/inner/job/(\\d{1,})/taskGroup/";
 List<String> patternStringList = Arrays.asList(dscJobUrlPatternString,
  dsJobUrlPatternString, dsTaskGroupUrlPatternString);
 jobId = parseJobIdFromUrl(patternStringList, jobPath);
}

boolean isStandAloneMode = "standalone".equalsIgnoreCase(RUNTIME_MODE);
if (!isStandAloneMode && jobId == -1) {
 // 如果不是 standalone 模式，那么 jobId 一定不能为-1
 throw DataXException.asDataXException(FrameworkErrorCode.CONFIG_ERROR, "非 standalone 模式必须在 URL 中提供有效的 jobId.");
}
configuration.set(CoreConstant.DATAX_CORE_CONTAINER_JOB_ID, jobId);

//打印vmInfo
VMInfo vmInfo = VMInfo.getVmInfo();
if (vmInfo != null) {
 LOG.info(vmInfo.toString());
}

LOG.info("\n" + Engine.filterJobConfiguration(configuration) + "\n");

LOG.debug(configuration.toJSON());

ConfigurationValidate.doValidate(configuration);
Engine engine = new Engine();
engine.start(configuration);
}

里面最后通过调用engine.start(configuration) 开始启动，我们点进去，最后会发现在里面是调用JobContainer 的start() 方法。

@Override
public void start() {
LOG.info("DataX jobContainer starts job.");

boolean hasException = false;
boolean isDryRun = false;
try {
 this.startTimeStamp = System.currentTimeMillis();
 isDryRun = configuration.getBool(CoreConstant.DATAX_JOB_SETTING_DRYRUN, false);
 if (isDryRun) {
 LOG.info("jobContainer starts to do preCheck ...");
 this.preCheck();
 } else {
 userConf = configuration.clone();
 LOG.debug("jobContainer starts to do preHandle ...");
 this.preHandle();

LOG.debug("jobContainer starts to do init ...");
 this.init();
 LOG.info("jobContainer starts to do prepare ...");
 this.prepare();
 LOG.info("jobContainer starts to do split ...");
 this.totalStage = this.split();
 LOG.info("jobContainer starts to do schedule ...");
 this.schedule();
 LOG.debug("jobContainer starts to do post ...");
 this.post();

LOG.debug("jobContainer starts to do postHandle ...");
 this.postHandle();
 LOG.info("DataX jobId [{}] completed successfully.", this.jobId);

this.invokeHooks();
 }
} catch (Throwable e) {
 LOG.error("Exception when job run", e);

hasException = true;

if (e instanceof OutOfMemoryError) {
 this.destroy();
 System.gc();
 }

if (super.getContainerCommunicator() == null) {
 // 由于 containerCollector 是在 scheduler() 中初始化的，所以当在 scheduler() 之前出现异常时，需要在此处对 containerCollector 进行初始化

AbstractContainerCommunicator tempContainerCollector;
 // standalone
 tempContainerCollector = new StandAloneJobContainerCommunicator(configuration);

super.setContainerCommunicator(tempContainerCollector);
 }

Communication communication = super.getContainerCommunicator().collect();
 // 汇报前的状态，不需要手动进行设置
 // communication.setState(State.FAILED);
 communication.setThrowable(e);
 communication.setTimestamp(this.endTimeStamp);

Communication tempComm = new Communication();
 tempComm.setTimestamp(this.startTransferTimeStamp);

Communication reportCommunication = CommunicationTool.getReportCommunication(communication, tempComm, this.totalStage);
 super.getContainerCommunicator().report(reportCommunication);

throw DataXException.asDataXException(
  FrameworkErrorCode.RUNTIME_ERROR, e);
} finally {
 if (!isDryRun) {

this.destroy();
 this.endTimeStamp = System.currentTimeMillis();
 if (!hasException) {
  //最后打印cpu的平均消耗，GC的统计
  VMInfo vmInfo = VMInfo.getVmInfo();
  if (vmInfo != null) {
  vmInfo.getDelta(false);
  LOG.info(vmInfo.totalString());
  }

LOG.info(PerfTrace.getInstance().summarizeNoException());
  this.logStatistics();
 }
 }
}
}

而我们需要的任务信息就在this.logStatistics() 中

private void logStatistics() {
long totalCosts = (this.endTimeStamp - this.startTimeStamp) / 1000;
long transferCosts = (this.endTransferTimeStamp - this.startTransferTimeStamp) / 1000;
if (0L == transferCosts) {
 transferCosts = 1L;
}

if (super.getContainerCommunicator() == null) {
 return;
}

Communication communication = super.getContainerCommunicator().collect();
communication.setTimestamp(this.endTimeStamp);

Communication tempComm = new Communication();
tempComm.setTimestamp(this.startTransferTimeStamp);

Communication reportCommunication = CommunicationTool.getReportCommunication(communication, tempComm, this.totalStage);

// 字节速率
long byteSpeedPerSecond = communication.getLongCounter(CommunicationTool.READ_SUCCEED_BYTES)
 / transferCosts;

long recordSpeedPerSecond = communication.getLongCounter(CommunicationTool.READ_SUCCEED_RECORDS)
 / transferCosts;

reportCommunication.setLongCounter(CommunicationTool.BYTE_SPEED, byteSpeedPerSecond);
reportCommunication.setLongCounter(CommunicationTool.RECORD_SPEED, recordSpeedPerSecond);

super.getContainerCommunicator().report(reportCommunication);

LOG.info(String.format(
 "\n" + "％-26s: ％-18s\n" + "％-26s: ％-18s\n" + "％-26s: ％19s\n"
  + "％-26s: ％19s\n" + "％-26s: ％19s\n" + "％-26s: ％19s\n"
  + "％-26s: ％19s\n",
 "任务启动时刻",
 dateFormat.format(startTimeStamp),

"任务结束时刻",
 dateFormat.format(endTimeStamp),

"任务总计耗时",
 String.valueOf(totalCosts) + "s",
 "任务平均流量",
 StrUtil.stringify(byteSpeedPerSecond)
  + "/s",
 "记录写入速度",
 String.valueOf(recordSpeedPerSecond)
  + "rec/s", "读出记录总数",
 String.valueOf(CommunicationTool.getTotalReadRecords(communication)),
 "读写失败总数",
 String.valueOf(CommunicationTool.getTotalErrorRecords(communication))
));

LOG.info("task-total-info:" + dateFormat.format(startTimeStamp) + "|" +
 dateFormat.format(endTimeStamp) + "|" +
 String.valueOf(totalCosts) + "|" +
 StrUtil.stringify(byteSpeedPerSecond) + "|" +
 String.valueOf(recordSpeedPerSecond) + "|" +
 String.valueOf(CommunicationTool.getTotalReadRecords(communication)) + "|" +
 String.valueOf(CommunicationTool.getTotalErrorRecords(communication))
);

if (communication.getLongCounter(CommunicationTool.TRANSFORMER_SUCCEED_RECORDS) > 0
 || communication.getLongCounter(CommunicationTool.TRANSFORMER_FAILED_RECORDS) > 0
 || communication.getLongCounter(CommunicationTool.TRANSFORMER_FILTER_RECORDS) > 0) {
 LOG.info(String.format(
  "\n" + "％-26s: ％19s\n" + "％-26s: ％19s\n" + "％-26s: ％19s\n",
  "Transformer成功记录总数",
  communication.getLongCounter(CommunicationTool.TRANSFORMER_SUCCEED_RECORDS),

"Transformer失败记录总数",
  communication.getLongCounter(CommunicationTool.TRANSFORMER_FAILED_RECORDS),

"Transformer过滤记录总数",
  communication.getLongCounter(CommunicationTool.TRANSFORMER_FILTER_RECORDS)
 ));
}
}

改造开始

新增返回实体DataxResult (get、set省略)

public class DataxResult {
//任务启动时刻
private long startTimeStamp;
//任务结束时刻
private long endTimeStamp;
//任务总时耗
private long totalCosts;
//任务平均流量
private long byteSpeedPerSecond;
//记录写入速度
private long recordSpeedPerSecond;
//读出记录总数
private long totalReadRecords;
//读写失败总数
private long totalErrorRecords;
//成功记录总数
private long transformerSucceedRecords;
// 失败记录总数
private long transformerFailedRecords;
// 过滤记录总数
private long transformerFilterRecords;
//字节数
private long readSucceedBytes;
//转换开始时间
private long endTransferTimeStamp;
//转换结束时间
private long startTransferTimeStamp;
//转换总耗时
private long transferCosts;

重写logStatistics方法，返回该实体。

private DataxResult logStatistics(DataxResult resultMsg) {
long totalCosts = (this.endTimeStamp - this.startTimeStamp) / 1000;
long transferCosts = (this.endTransferTimeStamp - this.startTransferTimeStamp) / 1000;
if (0L == transferCosts) {
 transferCosts = 1L;
}
if (super.getContainerCommunicator() == null) {
 return resultMsg;
}
Communication communication = super.getContainerCommunicator().collect();
long byteSpeedPerSecond = communication.getLongCounter(CommunicationTool.READ_SUCCEED_BYTES)
 / transferCosts;
long recordSpeedPerSecond = communication.getLongCounter(CommunicationTool.READ_SUCCEED_RECORDS)
 / transferCosts;

return resultMsg.getResultMsg(startTimeStamp,
 endTimeStamp,
 totalCosts,
 byteSpeedPerSecond,
 recordSpeedPerSecond,
 communication.getLongCounter(CommunicationTool.TRANSFORMER_SUCCEED_RECORDS),
 communication.getLongCounter(CommunicationTool.TRANSFORMER_FAILED_RECORDS),
 communication.getLongCounter(CommunicationTool.TRANSFORMER_FILTER_RECORDS),
 communication.getLongCounter(CommunicationTool.TRANSFORMER_FAILED_RECORDS),
 communication.getLongCounter(CommunicationTool.TRANSFORMER_FILTER_RECORDS),
 communication.getLongCounter(CommunicationTool.READ_SUCCEED_BYTES),
 this.endTransferTimeStamp,
 this.startTransferTimeStamp,
 transferCosts
);

}

还需要重写JobContainer的**start()**方法。

@Override
public DataxResult start(DataxResult dataxResult) {
...
DataxResult result = new DataxResult();
result = logStatistics(dataxResult);
...
return result;
}

然后在Engine 类中添加模拟测试方法mockentry

public DataxResult mockstart(Configuration allConf) {

...
DataxResult dataxResult = new DataxResult();
return container.start(dataxResult);
}

开始测试

在com.alibaba.datax.core.util.container.CoreConstant里修改datax_home 为本地路径

该datax_home路径下有以下几个目录

public class test {

public static void main(String[] args) {
String[] datxArgs = {"-job", CoreConstant.DATAX_HOME + "\\job\\job2.json", "-mode", "standalone", "-jobid", "-1"};
try {
 DataxResult dataxResult= Engine.mockentry(datxArgs);
} catch (Throwable e) {
 e.printStackTrace();
}

}
}

执行结果为

3

大功告成！

来源：https://blog.csdn.net/ffyangzhch/article/details/88784007