Vero Monitor Service

Description

The connection_mon probe checks whether a specific process currently holds an ESTABLISHED TCP connection to a service endpoint. Designed for “trace between two servers” — verifying connectivity between systems. Bidirectional matching: The same config can be deployed on both ends:

Forward: this host is the source (local = source, remote = dest service)
Reverse: this host is the dest (local = dest service, remote = source)

Requires both ProcessAdapter and ConnAdapter.

Config fields

Field	Type	Required	Default	Description
`type`	`string`	Yes	—	Must be `"connection_mon"`
`name`	`string`	Yes	—	Connection link identifier
`processName`	`string`	Yes	—	Process name glob (case-insensitive, same as `process_mon`)
`executablePath`	`string`	No	—	Executable path to narrow match (ANDed)
`destServiceIp`	`string`	Yes	—	Destination service IP (well-known end)
`destServicePort`	`int`	Yes	—	Destination service port (1–65535)
`sourceServiceIp`	`string`	No	—	Source IP (optional filter)
`sourceServicePort`	`int`	No	—	Source port (usually ephemeral, left unset)
`protocol`	`string`	No	`"tcp"`	Only `"tcp"` supported

Metrics

Metric	Type	Labels	Description
`vms.connection_mon.status`	status	`name`, `dest_ip`, `dest_port`, `proto`, `process_name`, `direction`	`up` or `down`
`vms.connection_mon.up`	gauge	(same)	`1` = ESTABLISHED connection found, `0` = none
`vms.agent.permission_missing`	gauge	`capability=CAP_SYS_PTRACE`	When agent cannot attribute sockets to PIDs

Example config

{
  "type": "connection_mon",
  "name": "app-to-postgres",
  "processName": "java",
  "destServiceIp": "10.0.1.50",
  "destServicePort": 5432
}

Notes

Only TCP ESTABLISHED state is considered “normal/healthy”.
Same config deployed on both ends: host A sees direction=forward, host B sees direction=reverse.
Without CAP_SYS_PTRACE, a process owned by another user shows 0 connections (false negative) with vms.agent.permission_missing emitted.