States and Transitions

States and Transitions

The following diagram shows the states that a server goes through during the lifetime.

Allowed State Transitions

digraph states {
  graph [pad=".35", ranksep="0.65", nodesep="0.55", concentrate=true];
  node [fontsize=10 fontname="Monospace"];
  edge [arrowhead="normal", arrowsize="0.8"];
  label="All states are allowed to transition to DELETING, MAINTENANCE and ERROR.";

  /* states */
  building [label="BUILDING"]
  active [label="ACTIVE"]
  stopped [label="STOPPED"]
  powering_on [label="POWERING_ON"]
  powering_off [label="POWERING_OFF"]
  soft_powering_off [label="SOFT_POWERING_OFF"]
  rebooting [label="REBOOTING"]
  soft_rebooting [label="SOFT_REBOOTING"]
  rebuilding [label="REBUILDING"]
  deleting [label="DELETING", color="red"]
  error [label="ERROR", color="red"]
  maintenance [label="MAINTENANCE", color="red"]

  /* transitions [action] */
  active -> rebuilding
  active -> powering_off
  active -> soft_powering_off
  active -> rebooting
  active -> soft_rebooting

  stopped -> powering_on
  stopped -> rebuilding

  building -> active
  rebuilding -> active
  powering_on -> active
  powering_off -> stopped
  soft_powering_off -> stopped
  rebooting -> active
  soft_rebooting -> active
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