public void start()

in hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/KeyManagerImpl.java [241:380]
129 lines of code
16 McCabe index (conditional complexity)

  public void start(OzoneConfiguration configuration) {
    boolean isCompactionEnabled = configuration.getBoolean(OZONE_OM_COMPACTION_SERVICE_ENABLED,
        OZONE_OM_COMPACTION_SERVICE_ENABLED_DEFAULT);
    startCompactionService(configuration, isCompactionEnabled);

    boolean isSnapshotDeepCleaningEnabled = configuration.getBoolean(OZONE_SNAPSHOT_DEEP_CLEANING_ENABLED,
        OZONE_SNAPSHOT_DEEP_CLEANING_ENABLED_DEFAULT);
    if (keyDeletingService == null) {
      long blockDeleteInterval = configuration.getTimeDuration(
          OZONE_BLOCK_DELETING_SERVICE_INTERVAL,
          OZONE_BLOCK_DELETING_SERVICE_INTERVAL_DEFAULT,
          TimeUnit.MILLISECONDS);
      long serviceTimeout = configuration.getTimeDuration(
          OZONE_BLOCK_DELETING_SERVICE_TIMEOUT,
          OZONE_BLOCK_DELETING_SERVICE_TIMEOUT_DEFAULT,
          TimeUnit.MILLISECONDS);
      keyDeletingService = new KeyDeletingService(ozoneManager,
          scmClient.getBlockClient(), this, blockDeleteInterval,
          serviceTimeout, configuration, isSnapshotDeepCleaningEnabled);
      keyDeletingService.start();
    }

    // Start directory deletion service for FSO buckets.
    if (dirDeletingService == null) {
      long dirDeleteInterval = configuration.getTimeDuration(
          OZONE_DIR_DELETING_SERVICE_INTERVAL,
          OZONE_DIR_DELETING_SERVICE_INTERVAL_DEFAULT,
          TimeUnit.MILLISECONDS);
      long serviceTimeout = configuration.getTimeDuration(
          OZONE_BLOCK_DELETING_SERVICE_TIMEOUT,
          OZONE_BLOCK_DELETING_SERVICE_TIMEOUT_DEFAULT,
          TimeUnit.MILLISECONDS);
      int dirDeletingServiceCorePoolSize =
          configuration.getInt(OZONE_THREAD_NUMBER_DIR_DELETION,
              OZONE_THREAD_NUMBER_DIR_DELETION_DEFAULT);
      if (dirDeletingServiceCorePoolSize <= 0) {
        dirDeletingServiceCorePoolSize = 1;
      }
      dirDeletingService =
          new DirectoryDeletingService(dirDeleteInterval, TimeUnit.MILLISECONDS,
              serviceTimeout, ozoneManager, configuration,
              dirDeletingServiceCorePoolSize);
      dirDeletingService.start();
    }

    if (openKeyCleanupService == null) {
      long serviceInterval = configuration.getTimeDuration(
          OZONE_OM_OPEN_KEY_CLEANUP_SERVICE_INTERVAL,
          OZONE_OM_OPEN_KEY_CLEANUP_SERVICE_INTERVAL_DEFAULT,
          TimeUnit.MILLISECONDS);
      long serviceTimeout = configuration.getTimeDuration(
          OZONE_OM_OPEN_KEY_CLEANUP_SERVICE_TIMEOUT,
          OZONE_OM_OPEN_KEY_CLEANUP_SERVICE_TIMEOUT_DEFAULT,
          TimeUnit.MILLISECONDS);
      openKeyCleanupService = new OpenKeyCleanupService(serviceInterval,
          TimeUnit.MILLISECONDS, serviceTimeout, ozoneManager, configuration);
      openKeyCleanupService.start();
    }

    if (snapshotSstFilteringService == null &&
        ozoneManager.isFilesystemSnapshotEnabled()) {

      long serviceInterval = configuration.getTimeDuration(
          OZONE_SNAPSHOT_SST_FILTERING_SERVICE_INTERVAL,
          OZONE_SNAPSHOT_SST_FILTERING_SERVICE_INTERVAL_DEFAULT,
          TimeUnit.MILLISECONDS);
      long serviceTimeout = configuration.getTimeDuration(
          OZONE_SNAPSHOT_SST_FILTERING_SERVICE_TIMEOUT,
          OZONE_SNAPSHOT_SST_FILTERING_SERVICE_TIMEOUT_DEFAULT,
          TimeUnit.MILLISECONDS);
      if (isSstFilteringSvcEnabled()) {
        snapshotSstFilteringService =
            new SstFilteringService(serviceInterval, TimeUnit.MILLISECONDS,
                serviceTimeout, ozoneManager, configuration);
        snapshotSstFilteringService.start();
      }
    }

    if (snapshotDeletingService == null &&
        ozoneManager.isFilesystemSnapshotEnabled()) {

      long snapshotServiceInterval = configuration.getTimeDuration(
          OZONE_SNAPSHOT_DELETING_SERVICE_INTERVAL,
          OZONE_SNAPSHOT_DELETING_SERVICE_INTERVAL_DEFAULT,
          TimeUnit.MILLISECONDS);
      long snapshotServiceTimeout = configuration.getTimeDuration(
          OZONE_SNAPSHOT_DELETING_SERVICE_TIMEOUT,
          OZONE_SNAPSHOT_DELETING_SERVICE_TIMEOUT_DEFAULT,
          TimeUnit.MILLISECONDS);
      try {
        snapshotDeletingService = new SnapshotDeletingService(
            snapshotServiceInterval, snapshotServiceTimeout,
            ozoneManager);
        snapshotDeletingService.start();
      } catch (IOException e) {
        LOG.error("Error starting Snapshot Deleting Service", e);
      }
    }

    if (isSnapshotDeepCleaningEnabled && snapshotDirectoryCleaningService == null &&
        ozoneManager.isFilesystemSnapshotEnabled()) {
      long dirDeleteInterval = configuration.getTimeDuration(
          OZONE_SNAPSHOT_DIRECTORY_SERVICE_INTERVAL,
          OZONE_SNAPSHOT_DIRECTORY_SERVICE_INTERVAL_DEFAULT,
          TimeUnit.MILLISECONDS);
      long serviceTimeout = configuration.getTimeDuration(
          OZONE_SNAPSHOT_DIRECTORY_SERVICE_TIMEOUT,
          OZONE_SNAPSHOT_DIRECTORY_SERVICE_TIMEOUT_DEFAULT,
          TimeUnit.MILLISECONDS);
      snapshotDirectoryCleaningService = new SnapshotDirectoryCleaningService(
          dirDeleteInterval, TimeUnit.MILLISECONDS, serviceTimeout,
          ozoneManager, scmClient.getBlockClient());
      snapshotDirectoryCleaningService.start();
    }

    if (multipartUploadCleanupService == null) {
      long serviceInterval = configuration.getTimeDuration(
          OZONE_OM_MPU_CLEANUP_SERVICE_INTERVAL,
          OZONE_OM_MPU_CLEANUP_SERVICE_INTERVAL_DEFAULT,
          TimeUnit.MILLISECONDS);
      long serviceTimeout = configuration.getTimeDuration(
          OZONE_OM_MPU_CLEANUP_SERVICE_TIMEOUT,
          OZONE_OM_MPU_CLEANUP_SERVICE_TIMEOUT_DEFAULT,
          TimeUnit.MILLISECONDS);
      multipartUploadCleanupService = new MultipartUploadCleanupService(
          serviceInterval, TimeUnit.MILLISECONDS, serviceTimeout,
          ozoneManager, configuration);
      multipartUploadCleanupService.start();
    }

    Class<? extends DNSToSwitchMapping> dnsToSwitchMappingClass =
        configuration.getClass(
            ScmConfigKeys.NET_TOPOLOGY_NODE_SWITCH_MAPPING_IMPL_KEY,
            TableMapping.class, DNSToSwitchMapping.class);
    DNSToSwitchMapping newInstance = ReflectionUtils.newInstance(
        dnsToSwitchMappingClass, configuration);
    dnsToSwitchMapping =
        ((newInstance instanceof CachedDNSToSwitchMapping) ? newInstance
            : new CachedDNSToSwitchMapping(newInstance));
  }