Ethernet and Coffee

The graph above shows the TCP output segment rate (shaded line, scaled on the left) and the percent retransmissions (connected dots, scaled on the right). The retran_pct value is calculated by feeding the perSecond data from both TcpOutSegs and TcpRetransSegs into Graphite'’s asPercent function.

The Grafana target for the TcpOutSegs rate is pretty straight forward:

{
  "hide": false,
  "target": "alias(perSecond(wumpus.nstat.TcpOutSegs), ''TcpOutSegs'')"
}

The target for the retran_pct value is more complicated since it references both the TcpOutSegs target as #A and also has a targetFull attribute.

{
  "hide": false,
  "target": "alias(asPercent(perSecond(wumpus.nstat.TcpRetransSegs), #A), ''retran_pct'')",
  "targetFull": "alias(asPercent(perSecond(wumpus.nstat.TcpRetransSegs), alias(perSecond(wumpus.nstat.TcpOutSegs), ''TcpOutSegs'')), ''retran_pct'')"
}