azkaban是沒有創(chuàng)建作業(yè)流,創(chuàng)建任務(wù),建立任務(wù)之間關(guān)系的操作的.
它本身的工作模式,在本地進(jìn)行編輯.創(chuàng)建任務(wù),創(chuàng)建作業(yè)流,建立依賴關(guān)系,然后打成zip上傳.

DirectoryFlowLoader解壓zip包,然后解析解壓出來的zip目錄.
首先需要兩個基礎(chǔ)類Node,Edge.
Node表示的是作業(yè)流中的節(jié)點信息,包含job文件名,properties屬性文件名,作業(yè)類型,
Edge表示的是節(jié)點之間邊信息.

loadProjectFlow

將project目錄解析成flow,properties json串,將一些無效的job,flow預(yù)先剔除掉.

無效的job:

• type屬性沒寫的
• 重復(fù)job(多次出現(xiàn)將會被剔除掉)

無效依賴:

• 只身依賴(自己依賴自己)
• 無效依賴(所依賴的job不存在)
• 依賴于job是個重復(fù)job

代碼

public void loadProjectFlow(Project project, File baseDirectory) {
    propsList = new ArrayList<Props>();//整個工程的.properties配置列表
    flowPropsList = new ArrayList<FlowProps>();//作業(yè)流.properties配置列表
    jobPropsMap = new HashMap<String, Props>();//jobName->.job配置
    nodeMap = new HashMap<String, Node>();//jobName->Node
    flowMap = new HashMap<String, Flow>();//flowName->Flow
    errors = new HashSet<String>();
    duplicateJobs = new HashSet<String>();//重復(fù)任務(wù)名(jobName)
    nodeDependencies = new HashMap<String, Map<String, Edge>>();//jobname->sourceJobName->依賴的邊
    rootNodes = new HashSet<String>();//根節(jié)點,解釋一下,這里的根節(jié)點是flow中最后的節(jié)點
    flowDependencies = new HashMap<String, Set<String>>();//flow于flow之間的依賴關(guān)系,解決內(nèi)嵌之間依賴關(guān)系

    // Load all the props files and create the Node objects
    loadProjectFromDir(baseDirectory.getPath(), baseDirectory, null);

    jobPropertiesCheck(project);

    // Create edges and find missing dependencies
    resolveDependencies();

    // Create the flows.
    buildFlowsFromDependencies();

    // Resolve embedded flows
    resolveEmbeddedFlows();

  }

loadProjectFlow函數(shù)用于解析工作目錄,解析job,構(gòu)建工作流.

第一步loadProjectFromDir(baseDirectory.getPath(), baseDirectory, null);
目的有兩個,一將配置文件解析成類,二排除文件重復(fù)job
加載.properties,.job文件,將加載的配置放入
flowPropsList,propsList.(.properties)
jobPropsMap,duplicateJobs,nodeMap.(.job)
nodeMap存儲的是所有的節(jié)點信息

jobPropertiesCheck函數(shù),檢查job任務(wù)屬性是否合格.azkaban中會限制每個任務(wù)最大內(nèi)存和最小內(nèi)存.如果超過job的社會超過限制,就會放入error中.

  private void jobPropertiesCheck(Project project) {
    // if project is in the memory check whitelist, then we don't need to check
    // its memory settings
    if (ProjectWhitelist.isProjectWhitelisted(project.getId(),
        ProjectWhitelist.WhitelistType.MemoryCheck)) {
      return;
    }

    String maxXms = props.getString(JOB_MAX_XMS, MAX_XMS_DEFAULT);
    String maxXmx = props.getString(JOB_MAX_XMX, MAX_XMX_DEFAULT);
    long sizeMaxXms = Utils.parseMemString(maxXms);
    long sizeMaxXmx = Utils.parseMemString(maxXmx);

    for (String jobName : jobPropsMap.keySet()) {

      Props jobProps = jobPropsMap.get(jobName);
      String xms = jobProps.getString(XMS, null);
      if (xms != null && !PropsUtils.isVarialbeReplacementPattern(xms)
          && Utils.parseMemString(xms) > sizeMaxXms) {
        errors.add(String.format(
            "%s: Xms value has exceeded the allowed limit (max Xms = %s)",
            jobName, maxXms));
      }
      String xmx = jobProps.getString(XMX, null);
      if (xmx != null && !PropsUtils.isVarialbeReplacementPattern(xmx)
          && Utils.parseMemString(xmx) > sizeMaxXmx) {
        errors.add(String.format(
            "%s: Xmx value has exceeded the allowed limit (max Xmx = %s)",
            jobName, maxXmx));
      }

      // job callback properties check
      JobCallbackValidator.validate(jobName, props, jobProps, errors);
    }
  }

resolveDependencies回溯依賴關(guān)系,得到所有Edge,將無效依賴排除(依賴的job不存在,依賴的job是重復(fù)job)

buildFlowsFromDependencies利用之前解析好Nodes,Edges,回溯形成flow.

//這里所謂的根節(jié)點是末節(jié)點
private void buildFlowsFromDependencies() {
    //找出所有的依賴節(jié)點
    // Find all root nodes by finding ones without dependents.
    HashSet<String> nonRootNodes = new HashSet<String>();
    for (Map<String, Edge> edges : nodeDependencies.values()) {
      for (String sourceId : edges.keySet()) {
        nonRootNodes.add(sourceId);
      }
    }

    // Now create flows. Bad flows are marked invalid
    Set<String> visitedNodes = new HashSet<String>();
    for (Node base : nodeMap.values()) {
      // Root nodes can be discovered when parsing jobs
      if (rootNodes.contains(base.getId())
          || !nonRootNodes.contains(base.getId())) {
        rootNodes.add(base.getId());
        Flow flow = new Flow(base.getId());
        Props jobProp = jobPropsMap.get(base.getId());

        // Dedup with sets
        @SuppressWarnings("unchecked")
        List<String> successEmailList =
            jobProp.getStringList(CommonJobProperties.SUCCESS_EMAILS,
                Collections.EMPTY_LIST);
        Set<String> successEmail = new HashSet<String>();
        for (String email : successEmailList) {
          successEmail.add(email.toLowerCase());
        }

        @SuppressWarnings("unchecked")
        List<String> failureEmailList =
            jobProp.getStringList(CommonJobProperties.FAILURE_EMAILS,
                Collections.EMPTY_LIST);
        Set<String> failureEmail = new HashSet<String>();
        for (String email : failureEmailList) {
          failureEmail.add(email.toLowerCase());
        }

        @SuppressWarnings("unchecked")
        List<String> notifyEmailList =
            jobProp.getStringList(CommonJobProperties.NOTIFY_EMAILS,
                Collections.EMPTY_LIST);
        for (String email : notifyEmailList) {
          email = email.toLowerCase();
          successEmail.add(email);
          failureEmail.add(email);
        }

        flow.addFailureEmails(failureEmail);
        flow.addSuccessEmails(successEmail);

        flow.addAllFlowProperties(flowPropsList);
        constructFlow(flow, base, visitedNodes);//不斷的遞歸,直到依賴為null為止
        flow.initialize();
        flowMap.put(base.getId(), flow);
      }
    }
  }