The current ACM state machine works but it is incosistent in the way it handles error states or failed transitions. A composition and its elements can get "stuck" in transition states.

We need to

Specify what the current state machine is for both compositions and elements and describe what the state machine for both should be
Specify what the behaviour of the runtime and participants should be in each state
Specify what the behaviour should be for the runtime and participants should be in transitions

Specifically we need to clarify:

State of the composition elements
State of the overall composition is derived from the composition element states
Admin state/Running state
When all the elements are fully up and configured, the go to state Passive, when all elements are in Passive, the full composition goes to Passive
Error states: Are they parallel sates or part of the same state?
There should “it didn’t work” states like “Passive-Error” or “Run_Error” (names to be decided later)
Describe what the “Running” state means and what the participant should do in Passive->Running and Running->Passive transitions.
Say a K8S service crashes, how do we feed that back? Running_Error. The state of the POD is only checked during startup. It is not periodically checked. There should be supervision.

ACM Element States in Participants

This section describes the state handling in ACM Elements in Participants

The following states are the only states in participants:

Then, a Control Loop Element can be running a number of operations, each of which has an operational state:

Operational State	From State	To State	Result	Triggered By	Description
No_Operation	None	None	N/A	None	No operation in progress
Initialize	UNINITIALIZED UNINITIALIZED	PASSIVE UNINITIALIZED_ERROR	Success Fail	ACM Runtime	Makes an ACM Element ready for operation
Uninitialize	PASSIVE PASSIVE PASSIVE_ERROR PASSIVE_ERROR	UNINITIALIZED PASSIVE_ERROR UNINITIALIZED PASSIVE_ERROR	Success Fail Success Fail	ACM Runtime	Takes an ACM Element out of operation
UnitializeReset	UNINITIALIZED_ERROR UNINITIALIZED_ERROR	UNINITIALIZED UNINITIALIZED_ERROR	Success Fail	ACM Runtime	Clear an uninitialization error on an ACM Element for operation
Activate	PASSIVE PASSIVE	RUNNING PASSIVE_ERROR	Success Fail	Participant	Bring an ACM element into service
PassiveReset	PASSIVE_ERROR PASSIVE_ERROR	PASSIVE PASSIVE_ERROR	Success Fail	ACM Runtime Participant	Clear an error on an ACM Element that is passive
ForceUninitialize	PASSIVE_ERROR	UNINITIALIZED_ERROR	N/A	ACM Runtime	Force a participant out of operation
Passivate	RUNNING RUNNING RUNNING_ERROR RUNNING_ERROR	PASSIVE RUNNING_ERROR PASSIVE RUNNING_ERROR	Success Fail	ACM Runtime Participant	Bring an ACM element out of service
RuntimeError	RUNNING	RUNNING_ERROR	N/A	Participant	Participant flags a runtime error
ClearRuntimeError	RUNNING_ERROR	RUNNING	N/A	pariticpant	Participant clears a runtime error flag
ForcePassive	RUNNING_ERROR	PASSIVE_ERROR	N/A	ACM Runtime	Force a participant out of runtime state

A Control Loop Element has a status indicator

Status Indicator	Description
OK	The ACM Element is stable in its current state
Information	The ACM Element is stable in its current state, and there is information available on the last operation on this ACM element
Warning	The ACM Element has a warning on its current state, and there is a warning on the last operation on this ACM element
Error	The ACM Element has an error on its current state, and there is a error message on the last operation on this ACM element

Each participant also records a log of all operations that occur, recording the information below:

Timestamp	Operational State	From State	To State	Status Before	Status After	Message
<..time..>	Initializing	UNINITIALIZED	PASSIVE	OK	OK
<..time..>	Activating	PASSIVE	RUNNING	OK	OK
<..time..>	Passivating	RUNNING	PASSIVE	OK	OK
<..time..>	Uninitializing	PASSIVE	UNINITIALIZED	OK	OK
<..time..>	Initializing	UNINITIALIZED	UNINITIALIZED	OK	ERROR	Error Messsage

ACM State Machine

ACM Element States in Participants