tcp.md

Collector: tcp

The TCP collector performs a TCP connect against the given host and port, recording timing metrics.

Syntax

collect tcp as path { (host, port) = [( "hostname", 80 ), ... ], ... }

• host In the tag section, selects the destination host; must be a string.
• port In the tag section, selects the destination port; must be a number.

Example

collect tcp as google {
  (host, port) = { ("www.google.com", 80) }
}

Create a single metric group google containing metrics on the TCP connect timing. This creates the following metrics:

google{host="www.google.com", port=80} {
  latency = 43,                                                    # 1
  up = true,                                                       # 2
  error.msg = (none),                                              # 3
  error.type = "OK",                                               # 4

  error.timed_out = false,                                         # 5
  error.no_route_to_host = false,
  error.port_unreachable = false,
  error.unknown_host = false,
  error.unknown_service = false,
  error.connect_failed = false,
  error.protocol_error = false,
  error.bind_failed = false,
  error.io_error = false
}

1. latency indicates the time until the connection was set up.
2. up indicates the connection succeeded.
3. error.msg indicates a (java) error message, explaining why the connect attempt failed.
4. error.type is the type of the error; "OK" indicates everything was fine. Otherwise it will correspond to one of the error types.
5. error.* is a boolean indicating if the specified error triggered.

To check multiple hosts, the parameters can be split:

collect tcp as social.media
  host = [ "www.facebook.com", "www.google.com", "www.twitter.com", "www.groupon.com" ],
  port = 80
}

Creates a TCP connection to the specified hosts, on port 80.