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Sentinel

Sentinels in Abyss Monitor probe your endpoints at a regular interval to measure availability and latency. Each Sentinel is attached to an Application and runs continuously, independently of application logs or events.

Sentinel types​

Three types cover common needs:

PING​

Sends an ICMP ping to a host (host). Ideal to check that a machine or network device responds.

HTTP​

Performs an HTTP request (GET, POST, etc.) against a URL. You can configure:

  • the headers to send,
  • SSL verification (enabled by default, with an option to allow self-signed certificates),
  • accepted response status codes,
  • a body assertion (contains or regex).

TCP​

Opens a TCP connection to a host:port. Useful to monitor a database, a broker, or any internal service without HTTP.

Success policy​

Each Sentinel defines an acceptable latency range (min, max in milliseconds). A check is treated as success if:

  • the request succeeds according to the type's rules (ping received, expected HTTP status, TCP connection opened),
  • latency is within the range,
  • the optional body assertion passes.

Otherwise the check is a failure. A retry policy (up to 5 attempts) avoids false positives on transient drops.

Create a Sentinel​

  1. Open the relevant Application in Abyss Monitor.
  2. Go to the Sentinels tab and click Create.
  3. Pick the type (PING, HTTP, TCP) and fill in the target.
  4. Set the acceptable latency range and, for HTTP, the headers and assertion rules.
  5. Confirm: the Sentinel starts immediately.

Visualize Sentinels​

The Sentinels list shows for each one:

  • the current status (success / failure),
  • the recent average latency,
  • the date of the last check.

Click a Sentinel to see the check history: every check is kept along with its latency, status, metadata (HTTP code, SSL info, etc.) and any error message.

Alerts and webhooks​

A Sentinel can trigger:

  • an alert (in-app Abyss notification), configured from the Alerts tab;
  • a SENTINEL webhook, notifying an external URL on transition to success and/or failure. You filter by Sentinel type and by transition direction. See Webhooks for details.