NDTS Daemon Operation
- NAN Data Transport System
- NDTS Overview
- NDTS Installation
- TopSpin 3.x Requirement
- Managing, Monitoring, and Logging
- NDTS Usage Guides
Overview
This page explains how to control the data-transport-daemon service, verify connectivity, and interpret the daemon’s log and audit files on every spectrometer workstation.
TopSpin version prior to 4.x
The daemon tracks experiment start/stop times from the TopSpin account file. By default, TopSpin accounting is not enabled. For NAN to properly automatically harvest datasets, TopSpin accounting must be enabled in each workstation users account. Follow these instructions to enable Accounting.
Service Control
# Start the daemon sudo /sbin/service data-transport-daemon start # Stop the daemon sudo /sbin/service data-transport-daemon stop # Restart (reloads configuration) sudo /sbin/service data-transport-daemon restart # Check status sudo /sbin/service data-transport-daemon status
- Note, the daemon will not start again if another instance is already running
Heartbeats and Connectivity
On a regular basis (by default, every 10 minutes), each NDTS daemon sends a heartbeat message to the Gateway. These messages serve as a continuous health check and confirm that the daemon is active and communicating. Each heartbeat contains a set of diagnostic and identity information used for system monitoring and troubleshooting and includes:
- Workstation hostname
- Current local datetime on the workstation
- Workstation IP address
- Currently selected NMRhub user
- Daemon version
- Facility and spectrometer identifiers
- Operating system details
- Uptime and system load metrics
The Gateway receives the heartbeat, appends its own identifying information (including Gateway UUID and timestamps), and forwards the full message to the NDTS Receiver. These heartbeats are recorded in the NAN Repository and are viewable by Facility Managers via the virtual NAN Operations Center (vNOC).
Slack Notifications
When heartbeats stop, the Receiver alerts the facility via the associated Slack channel.
Condition | Time-out | Receiver Action | Slack Message |
---|---|---|---|
First missed heartbeat | > 20 min | Mark workstation offline | offline |
Still missing at next poll | + 8 min | Repeat offline (max 3) | offline |
Heartbeat resumes | – | Mark workstation online | online |
In practical terms, if you subscribe to the Slack channel for your facility you will know within 20 minutes if a daemon went off-line, but you will see a maximum of three offline messages to not flood the Slack channel with the same offline message over and over. A single, online, message will appear in the Slack channel when heartbeats resume.
Slack channels (one per facility):
ccrc-ndts-notifications
nmrfam-ndts-notifications
uchc-ndts-notifications
Logging
Logging of the Daemon is performed in different files. (A) The file running_workstation_version-X.Y.Z
is used to log the current workstation version. (B) The ndtd_audit.txt
file for monitoring actions performed by the Daemon such as when datasets complete and what the harvesting status for the dataset. (C) the nan-dtdaemon.log
is used to log status changes needed by the daemon to properly harvest datasets and associate them to the correct NAN users.
(A) Version Tracking
- When the Daemon starts it writes the active version number in two places ...
/opt/nan-dtdaemon/running_workstation_version-X.Y.Z
which records the version number and a timestamp of when the daemon started, and
/opt/nan-dtdaemon/logs/nan-dtdaemon.log
which write an INFO message stating the version number and which is time-stamped
(B) Experiment Transfer Audit File
Each time the NDTS daemon processes a completed experiment, it logs a detailed audit entry to the file
/opt/nan-dtdaemon/logs/ndtd_audit.txt
This audit trail provides traceable records of all harvesting actions performed by the daemon on a given spectrometer workstation
Each line in the audit file includes the following fields:
- Timestamp when the log entry was written
- Workstation OS-level username (Linux/Windows)
- Selected NMRhub username (or
unselected
if none was selected) - Experiment start time
- Experiment end time
- Full path to the experiment data directory
- Version number of the NDTS daemon
- Action performed by the daemon
Possible Actions Logged
Action | Meaning |
---|---|
sent |
Experiment was successfully transferred to the Gateway |
spooled |
Experiment was queued locally for later transfer |
sent-spooled |
Experiment was sent from a previously spooled location |
skipped-trivial |
Experiment was ignored because it was deemed trivial (e.g., shim or calibration) |
skipped-disabled |
Experiment was skipped due to daemon or GUI configuration disabling harvesting |
(C) Daemon Logging
Detailed logging of the daemon for detecting things such as workstation users changing, TopSpin starting, which users version of TopSpin is controlling the spectrometer, when a different NAN user is selected, which files to monitor for experiment completions, and others. The logs are saved to
/opt/nan-dtdaemon/logs/nan-dtdaemon.log
Log Levels
Each line begins with a level tag. The level is controlled by the
log_level
parameter in the configuration file ndtd_configuration.dat
.
Level | Verbosity | Typical Use |
---|---|---|
fatal | Highest-priority, least frequent | Events that make the daemon shut down and cannot be auto-recovered |
error | Critical problems | Failures that stop normal operation but daemon continues running |
warning | Important but non-fatal issues | Conditions worth attention; daemon recovers automatically |
info | Default | Unusual or noteworthy events; normal operations generate very little output |
debug | Diagnostic detail | Ongoing list of major operations; log grows steadily |
trace | Maximum detail | Every internal step; use only for short troubleshooting sessions |
Log File Example
The fragment below is reproduced verbatim from the PDF (pp. 14-15):
Thu Sep 28 13:17:03 2023 LOG_START Started dtd logger. Thu Sep 28 13:17:03 2023 INFO NDTD Workstation version is 1.0.15 Thu Sep 28 13:17:03 2023 INFO *** This is a Topspin Workstation *** Thu Sep 28 13:17:03 2023 INFO Ndtd Control Processor listening. Thu Sep 28 13:17:03 2023 INFO Entering polling loop... Thu Sep 28 13:17:03 2023 INFO Workstation user has changed! Thu Sep 28 13:17:03 2023 INFO workstation user is nmradmin Thu Sep 28 13:17:03 2023 INFO User nmradmin is included in NAN data collection! Thu Sep 28 13:17:03 2023 INFO Harvesting setting for user nmradmin is on Thu Sep 28 13:17:03 2023 INFO Topspin program has been detected and is running. Thu Sep 28 13:17:03 2023 INFO Setting directory to watch to /opt/topspin4.2.0/prog/curdir/nmradmin/shmem
Analysis of the Example
- "LOG_START" — is the first line indicating the new instance of the daemon and the data and time that it started.
- "Workstation version is 1.0.15” — indicates the daemon is running and the version number
- “*** This is a Topspin Workstation ***” — indicates that this is a Topspin workstation
- “Ndtd Control Processor listening.” — indicates that the daemon is listening for incoming control commands
- “Entering polling loop…” — indicates that the daemon has entered the acquisition polling loop
- "Workstation user has changed!" and next three lines — indicates that the workstation user has changed to nmradmin, that nmradmin is configured to harvest data, and that the harvesting setting is on
- “Topspin program has been detected and is running.” — daemon detected that the Topspin acquisition directory running
- “Setting directory to watch to …” — shows the location of the Topspin directory which the daemon will watch for file modifications that indicate the start and end of an acquisition