NATS Front End Service
Overview
The NATS Front End Service brings alarm traffic into SBN from a message stream rather than from a direct connection to a receiver. Where the classic Front End listens on a network port for incoming alarm data, this version subscribes to a named stream on a messaging system and picks up alarm signals as they are published to it. Each signal it receives is placed into the SBN alarm queue for operators to handle, and the message is only confirmed back to the stream once SBN has accepted it — so nothing is lost if the service or the connection stops mid-delivery. Duplicate signals are recognised and discarded, so a message that gets redelivered does not create a second alarm.
Like the classic Front End, this service runs as numbered instances: install as many as you need and each one is configured separately, so different streams or different alarm sources can be handled side by side. The service requires a working SBN data-server connection and the address and credentials of the messaging system; if either is unavailable at start-up the service logs the reason and stops. It reconnects on its own if the stream connection drops.
Dashboard
Installing and managing this service is done from the SBN Services Dashboard — see <a href="/help/SBN-Services/Dashboard">here</a>.
Service Properties
Only properties specific to this service are listed here. Common service properties (SBN Server connection, Logging, SMTP) are found <a href="/help/SBN-Services/Common-Properties">here</a>.
NATS servers
The address or addresses of the messaging servers the service connects to. More than one can be given so the service can fall back to another server if the first is unreachable.
NATS Stream name
The name of the stream that alarm traffic is published to.
NATS Consumer name
The name this service subscribes under. Giving each instance its own consumer name keeps their positions in the stream separate.
NATS user
The user name the service authenticates to the messaging system with.
NATS Password
The password that goes with the user name above.
Immediate Queue
Sets which alarm queue incoming signals are placed into for operator handling.
ZREC
The receiver identity recorded against signals this service brings in, so alarms can be traced back to their source.
ZREC Timer (in seconds)
How long the service waits before trying the stream connection again after it has been interrupted.
Store signal id in
Selects which field the incoming signal's identifier is stored in when the alarm is written to SBN.
Store Signal Receive Utc Tm in
Selects which field records the time the signal was originally received, in UTC.
Store signal receive localtime offset in
Selects which field records how far local time differs from UTC for that signal, so the original local time can be worked back out.
Store trace id in
Selects which field stores the tracing identifier carried on the message, used to follow a single signal through the system when investigating an issue.