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products:promonitor:latest:userguide:administration:os-agent:monitor

OS Agent - Monitor

The Monitor tab lists every host that pushes metrics to this Collector, with their status and last activity. It is also where you can link a host to a System, deactivate it, or remove it.

Host list

Each row shows:

Column Meaning
Hostname The host's network name as reported in the host tag of the push. Case-insensitive, used as the unique identifier inside the Collector.
System The linked System short name, or - if the host is standalone.
Status OK / ERROR / OFF. See below.
OS linux, windows, or empty when not detected.
Last Push Time of the last received push. Never if the host has been registered but never pushed.
Active ON (accepts pushes) or OFF (rejects pushes with 403).

Click a row to expand the detail for the host.

Status values

  • OK (green) - the host is active and has pushed within the last 5 minutes
  • ERROR (red) - the host is active but has not pushed in the last 5 minutes
  • OFF (grey) - the host is set inactive in the Collector - all incoming pushes for this host are rejected

The 5-minute threshold is fixed in the Collector. Telegraf default flush interval is 15 seconds, so a missed push of more than 20 cycles is a real problem (network down, Telegraf crashed, host shut down).

Host detail (expanded)

When you click a host row, the panel below shows the last received values:

Top metrics grid

Four big cards: CPU, Memory, Swap, Load Average. Each shows the latest known value (used percent for CPU/Mem/Swap, 1-minute load with 5m/15m below).

Disk Usage

A table with one row per mount point (Linux) or drive letter (Windows), with the used percent. Color codes:

  • < 75% → green
  • 75-90% → orange
  • > 90% → red

Top Processes

A table with the top processes ranked by CPU, Memory, or Disk I/O (button toggles at the top right of the panel). Up to 20 processes are listed.

  • CPU % - per-process CPU usage as reported by Telegraf
  • Memory - resident set size (RSS) - actual physical memory used
  • Disk I/O - read and write bytes since the process started

If you do not see any process, the most likely causes are:

  • The process input is not enabled in the Configuration tab → enable it and redeploy the agent
  • The agent has not pushed yet → wait 30 seconds (procstat sends every 30s by default)
  • On Linux Docker without SYS_PTRACE, the process list works but read/write bytes will be zero (see the process monitoring section)

Bottom info row

  • Processes - total / running / zombies (from the processes input - Linux only)
  • Network - bytes sent (↑) and received (↓) per interface, in human-readable units
  • First Seen - when the host was first auto-discovered

Actions per host

Remap to a System

Use the Remap to System dropdown to link the host to a System (or set it back to Standalone).

  • When a host is linked to a System, its metrics get the System tags automatically (sid, system name, etc.) - dashboards by System include them
  • When standalone, metrics are stored with only the host tag - they still go through the pipeline but they are not associated to any System

Click Save to apply the link.

Activate / Deactivate

The Activate / Deactivate button (pause icon when ON, play when OFF) toggles the Active flag on the host:

  • OFF rejects every incoming push from this host with 403 Forbidden
  • ON accepts pushes again

Useful when you want to silence a host temporarily without uninstalling Telegraf.

Delete

Removes the host from the database. The next push from this host will re-create it as a new entry (with Standalone link, so you will need to re-map it).

Use this to clean up old hosts that no longer exist.

Refresh

A Refresh button at the top of the panel reloads the host list and detail. The list does not auto-refresh - click Refresh after waiting a few seconds to see the new values.

Auto-discovery

Hosts appear automatically the first time they push successfully:

  1. The Collector parses the host tag from the first metric line
  2. It checks the in-memory map and the database
  3. If unknown, tries to resolve a System by matching the hostname (case-insensitive) against the existing connectors
  4. If it matches a connector, the host is auto-linked to that System
  5. Otherwise the host is standalone

You do not need to pre-register hosts. Just install Telegraf and they show up.

products/promonitor/latest/userguide/administration/os-agent/monitor.txt · Last modified: by jtbeduchaud