Capturing the Status of Nodes in a File

DAGMan can capture the status of the overall DAG and all DAG nodes in a node status file, such that the user or a script can monitor this status. This file is periodically rewritten while the DAG runs. To enable this feature, the DAG input file must contain a line with the NODE_STATUS_FILE command.

The syntax for a NODE_STATUS_FILE command is

NODE_STATUS_FILE statusFileName [minimumUpdateTime] [ALWAYS-UPDATE]

The status file is written on the machine on which the DAG is submitted; its location is given by statusFileName, and it may be a full path and file name.

The optional minimumUpdateTime specifies the minimum number of seconds that must elapse between updates to the node status file. This setting exists to avoid having DAGMan spend too much time writing the node status file for very large DAGs. If no value is specified, this value defaults to 60 seconds (as of version 8.5.8; previously, it defaulted to 0). The node status file can be updated at most once per DAGMAN_USER_LOG_SCAN_INTERVAL no matter how small the minimumUpdateTime value. Also, the node status file will be updated when the DAG finishes, whether successfully or not, even if minimumUpdateTime seconds have not elapsed since the last update.

Normally, the node status file is only updated if the status of some nodes has changed since the last time the file was written. However, the optional ALWAYS-UPDATE keyword specifies that the node status file should be updated every time the minimum update time (and DAGMAN_USER_LOG_SCAN_INTERVAL), has passed, even if no nodes have changed status since the last time the file was updated. The file will change slightly, because timestamps will be updated. For performance reasons, large DAGs with approximately 10,000 or more nodes are poor candidates for using the ALWAYS-UPDATE option.

As an example, if the DAG input file contains the line

NODE_STATUS_FILE my.dag.status 30

the file my.dag.status will be rewritten at intervals of 30 seconds or more.

This node status file is overwritten each time it is updated. Therefore, it only holds information about the current status of each node; it does not provide a history of the node status.

Changed in version 8.1.6: HTCondor version 8.1.6 changes the format of the node status file.

The node status file is a collection of ClassAds in New ClassAd format. There is one ClassAd for the overall status of the DAG, one ClassAd for the status of each node, and one ClassAd with the time at which the node status file was completed as well as the time of the next update.

Here is an example portion of a node status file:

  Type = "DagStatus";
  DagFiles = {
  Timestamp = 1399674138;
  DagStatus = 3;
  NodesTotal = 12;
  NodesDone = 11;
  NodesPre = 0;
  NodesQueued = 1;
  NodesPost = 0;
  NodesReady = 0;
  NodesUnready = 0;
  NodesFailed = 0;
  JobProcsHeld = 0;
  JobProcsIdle = 1;
  Type = "NodeStatus";
  Node = "A";
  NodeStatus = 5;
  StatusDetails = "";
  RetryCount = 0;
  JobProcsQueued = 0;
  JobProcsHeld = 0;
  Type = "NodeStatus";
  Node = "C";
  NodeStatus = 3;
  StatusDetails = "idle";
  RetryCount = 0;
  JobProcsQueued = 1;
  JobProcsHeld = 0;
  Type = "StatusEnd";
  EndTime = 1399674138;
  NextUpdate = 1399674141;

Possible DagStatus and NodeStatus attribute values are:

  • 0 (STATUS_NOT_READY): At least one parent has not yet finished or the node is a FINAL node.

  • 1 (STATUS_READY): All parents have finished, but the node is not yet running.

  • 2 (STATUS_PRERUN): The node’s PRE script is running.

  • 3 (STATUS_SUBMITTED): The node’s HTCondor job(s) are in the queue.

  • 4 (STATUS_POSTRUN): The node’s POST script is running.

  • 5 (STATUS_DONE): The node has completed successfully.

  • 6 (STATUS_ERROR): The node has failed.

  • 7 (STATUS_FUTILE): The node will never run because ancestor node failed.

An ancestor is a node that a another node depends on either directly or indirectly through a chain of PARENT/CHILD relationships. For example, the DAG shown below would result in node G’s ancestors to be nodes A, B, D, and F because the PARENT to CHILD relationships appear as A & B -> D -> F -> G

Example DAG Visualized
      A     B

A NODE_STATUS_FILE command inside any splice is ignored. If multiple DAG files are specified on the condor_submit_dag command line, and more than one specifies a node status file, the first specification takes precedence.