NDTS Gateway Installation

Gateway Installation

Prerequisites

• A Gateway UUID supplied by the NAN Repository administrator
• A Linux host (Ubuntu 20.04 or later recommended) reachable by all workstations
• TCP port 60195 open inbound from those workstations

Installation Steps

# Copy the .gz file to the gateway computer
tar xf data-transport-gateway-<version>.tar.gz
cd dtgateway-installer
sudo ./install.sh
# → You will be prompted only for the Gateway UUID

Firewall Note

Open port 60195 to each NDTS workstation; no other inbound ports are required.

Verifying the Service

sudo systemctl status data-transport-gateway      # should show “active (running)”
sudo systemctl start  data-transport-gateway      # start if not running

Updating the Gateway

# Run the same installer script from a newer package
cd dtgateway-installer
sudo ./install.sh             # auto-detects an existing install; no prompts

Follow the directions above for verifying the service after updating the Gateway to ensure that the service is running.

Uninstalling the Gateway

sudo ./uninstall.sh           # script is included inside every package

Rolling Back the Gateway

Obtain the desired older package and run its install.sh. Rolling back more than one or two versions is not recommended.

NDTS Gateway Configuration

Configuration Options

Gateway configuration parameters

Option	Description	Default
log_file_path	Path to write the gateway log file	/opt/nandt-gateway/nan-gateway.log
logging_level	Minimum severity written to the log (fatal → debug)	info
logging_format	Python logging format string for each line	%(asctime)s %(levelname)s %(module)s [%(process)d]: %(message)s
base_output_path	Directory used for incoming experiment data	/opt/nandt-gateway/data/received
https_endpoint	HTTPS endpoint of the NDTS Receiver	https://receiver.usnan.org
retry_limit	Attempts to forward each dataset to the Receiver	5
retry_delay	Seconds to wait between retry attempts	300
rsync_username	SSH/rsync account on the Receiver	nandt
rsync_node	Node to which experiment files are rsync’d	receiver.usnan.org
request_queue_size	Outstanding daemon connections accepted before new ones are rejected	50

{
  "log_file_path": "/opt/nandt-gateway/nan-gateway.log",
  "logging_level": "info",
  "logging_format": "%(asctime)s %(levelname)s %(module)s [%(process)d]: %(message)s",
  "base_output_path": "/opt/nandt-gateway/data/received",
  "https_endpoint": "https://receiver.usnan.org",
  "retry_limit": 5,
  "retry_delay": 300,
  "rsync_username": "nandt",
  "rsync_node": "receiver.usnan.org",
  "request_queue_size": 50
}

Logging Levels

Gateway logging levels

Level	Description
debug	Detailed diagnostic messages useful for troubleshooting
info	Unusual or noteworthy events (recommended for production)
warning	Unusual events that generally require no action
error	Problems that must be addressed for normal operation
fatal	Critical events after which the gateway shuts down

NDTS Gateway Components

All files reside under /opt/nandt-gateway unless noted. :contentReference[oaicite:1]{index=1}

• main.py – entry point for the Python service
• /etc/systemd/system/data-transport-gateway.service – systemd unit file
• nan-gateway.log – runtime log (path overridable via log_file_path)
• gateway_configuration.json – configuration described above
• data/
  • received/ – transient storage for incoming experiment data
  • retransmitter.pid – PID of the active retransmitter helper
  • users.dat – current user / sample / project list
  • user_checksum.dat – checksum that governs list refreshes

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NDTS Operation

• Experiment transfer – Workstation daemons connect on TCP 60195, announce a dataset, and stream it to received/. Successful transfers spawn a **Transmitter** process that forwards the data to the receiver; on success the local copy is deleted. :contentReference[oaicite:2]{index=2}
• Retransmit – At start-up and after each daemon heartbeat, a **Retransmitter** scans received/. If a dataset’s original retry window has expired, it launches a new Transmitter until delivery succeeds or the file is manually removed.
• Heartbeat forwarding – Every daemon heartbeat is wrapped with the gateway UUID, local and UTC timestamps, then sent to the receiver by a short-lived **Heartbeat Transmitter**.
• User list propagation – Every 15 s the gateway requests an updated list from the receiver; if the checksum differs it saves the new list to users.dat and serves it to workstations on demand.

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NDTS Logging

Logging level is controlled by the "logging_level" key in gateway_configuration.json. Levels (high → low volume): fatal, error, warning, info, debug. Default is info. The log file path defaults to /opt/nandt-gateway/nan-gateway.log. :contentReference[oaicite:3]{index=3}

Example log excerpt:

2022-06-06 09:22:23,130 INFO main [61393]: Starting gateway retransmitter instance...
2022-06-06 09:22:23,132 INFO main [61393]: Starting gateway receiver network endpoint...
2022-06-06 09:23:12,829 INFO GatewayTransmitter [61512]: Heartbeat sent to https://receiver.usnan.org/heartbeat

:contentReference[oaicite:4]{index=4}