Worker State Machine¶
![digraph rug {
// rankdir=LR;
node [shape = rectangle];
START;
// These nodes enter and exit the state machine.
node [shape = doublecircle];
EXIT;
CALC_ACTION;
node [shape = circle];
START -> CALC_ACTION;
CALC_ACTION -> ALIVE [ label = "ACT>[CRUP],vm:[UC]" ];
CALC_ACTION -> CREATE_VM [ label = "ACT>[CRUP],vm:D" ];
CALC_ACTION -> CHECK_BOOT [ label = "ACT>[CRUP],vm:B" ];
CALC_ACTION -> REBUILD_VM [ label = "ACT:E" ];
CALC_ACTION -> STOP_VM [ label = "ACT>D or vm:G" ];
CALC_ACTION -> CLEAR_ERROR [ label = "vm:E" ];
ALIVE -> CREATE_VM [ label = "vm>D" ];
ALIVE -> CONFIG [ label = "ACT:[CU],vm:[UC]" ];
ALIVE -> STATS [ label = "ACT:R,vm:C" ];
ALIVE -> CALC_ACTION [ label = "ACT:P,vm>[UC]" ];
ALIVE -> STOP_VM [ label = "vm:G" ];
CREATE_VM -> CHECK_BOOT [ label = "ACT:[CRUDP],vm:[DBUCR]" ];
CREATE_VM -> STOP_VM [ label = "vm:G" ];
CREATE_VM -> CALC_ACTION [ label = "vm:E" ];
CREATE_VM -> CREATE_VM [ label = "vm:D" ];
CHECK_BOOT -> CONFIG [ label = "vm>U" ];
CHECK_BOOT -> CALC_ACTION [ label = "vm:[BCR]" ];
CHECK_BOOT -> STOP_VM [ label = "vm:[DG]" ];
CONFIG -> STATS [ label = "ACT:R,vm>C" ];
CONFIG -> CALC_ACTION [ label = "ACT>P,vm>C" ];
CONFIG -> REPLUG_VM [ label = "vm>[H]" ];
CONFIG -> STOP_VM [ label = "vm>[RDG]" ];
REPLUG_VM -> CONFIG [ label = "vm>[H]" ];
REPLUG_VM -> STOP_VM [ label = "vm>[R]" ];
STATS -> CALC_ACTION [ label = "ACT>P" ];
CLEAR_ERROR -> CALC_ACTION [ label = "no pause before next action" ];
REBUILD_VM -> REBUILD_VM [ label = "vm!=[DG]" ];
REBUILD_VM -> CREATE_VM [ label = "ACT:E,vm:D" ];
STOP_VM -> CREATE_VM [ label = "ACT:E or vm>D" ];
STOP_VM -> EXIT [ label = "ACT:D,vm>D or vm:G" ];
}](_images/graphviz-487fc744abaea36ad2c9b050c57da18378e891e6.png)
States¶
| CALC_ACTION: | Coalesces the pending actions from the queue inside the state machine. |
|---|---|
| ALIVE: | Checks whether the instance is alive. |
| CLEAR_ERROR: | Clear the error status before attempting any further operation. |
| STATS: | Reads traffic data from the router. |
| CREATE_VM: | Makes a new VM instance. |
| CHECKBOOT: | Check if a new VM instance has been booted and initially configured. |
| CONFIG: | Configures the VM and its services. |
| REPLUG_VM: | Attempts to replug the VM with a new network (or remove an unplugged one). |
| STOP_VM: | Terminates a running VM. |
| EXIT: | Processing stops. |
ACT(ion) Variable¶
| Create: | Create router was requested. |
|---|---|
| Read: | Read router traffic stats. |
| Update: | Update router configuration. |
| Delete: | Delete router. |
| Poll: | Poll router alive status. |
| rEbuild: | Recreate a router from scratch. |
vm Variable¶
| Down: | VM is known to be down. |
|---|---|
| Booting: | VM is booting. |
| Up: | VM is known to be up (pingable). |
| Configured: | VM is known to be configured. |
| Restart Needed: | VM needs to be rebooted. |
| Hotplug Needed: | VM needs to be replugged. |
| Gone: | The router definition has been removed from neutron. |
| Error: | The router has been rebooted too many times, or has had some other error. |