...

• 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.

State Machine for Automation Compositions

Current State Machine

• Composition in UNINITIALIZED state: all elements of a composition are in UNINITIALIZED state, all applications are not deployed and policy types are not deployed and not present in Api.
• User triggers to move the composition from UNINITIALIZED to PASSIVE: runtime-acm moves elements from UNINITIALIZED state to UNINITIALIZED_TO_PASSIVE.
• Element in UNINITIALIZED_TO_PASSIVE:
  • participant-ks8: deploys applications
  • participant-policy: creates policy types in Api and deploys them with Pap.
  • participant-http: configures applications.
• Element in PASSIVE state:
  • participant-ks8: applications are deployed.
  • participant-policy: policy types are create in Api and deployed with Pap.
  • participant-http: applications are configured.
• Composition in PASSIVE state: all elements are in PASSIVE state, all applications are deployed and configured.
• User triggers to move the composition from PASSIVE to UNINITIALIZED: runtime-acm moves elements from PASSIVE state to PASSIVE_TO_UNINITIALIZED.
• Element in UNINITIALIZED_TO_PASSIVE:
  • participant-ks8: undeploys applications
  • participant-policy: undeploys policy types with Pap and deletes them in Api.
  • participant-http: do nothing
• Element in UNINITIALIZED state:
  • participant-ks8: applications are undeployed.
  • participant-policy: policy types are not deployed and not present in Api.

Proposed State Machine

State Machine for Automation Composition Elements

Current State Machine

TBC

Proposed State Machine

Proposed State Machine

• Composition in UNINITIALIZED state: all elements of a the composition are in UNINITIALIZED state, all applications are not deployed and policy types are not deployed and not present in Api.
• User triggers to move the composition from UNINITIALIZED to PASSIVE: runtime-acm moves elements from UNINITIALIZED state to UNINITIALIZED_TO_PASSIVE.
• Element in UNINITIALIZED_TO_PASSIVE:
  • participant-ks8: deploys applications
  • participant-policy: creates policy types in Api and deploys them with Pap.
  • participant-http: checks if applications are healthy.
• Element in UNINITIALIZED_TO_PASSIVE_ERROR state: participant got error during deploy.
• Composition in UNINITIALIZED_TO_PASSIVE_ERROR state: at least one element is in UNINITIALIZED_TO_PASSIVE_ERROR state.
  • User can re-try UNINITIALIZED_TO_PASSIVE.
  • User can go back to UNINITIALIZED.
• Element in PASSIVE state:
  • participant-ks8: applications are deployed.
  • participant-policy: policy types are create in Api and deployed with Pap.
  • participant-http: applications are healthy but not configured yet.
• Composition in PASSIVE state: all elements are moved to PASSIVE, all applications are deployed but not configured.
• User triggers to move the composition from PASSIVE to RUNNING: runtime-ACM moves elements from PASSIVE state to PASSIVE_TO_RUNNING.
• Element in PASSIVE_TO_RUNNING state:
  
  • participant-ks8: do nothing (maybe checks if applications are running).
  • participant-policy: do nothing (maybe checks if policy types are running).
  • participant-http: configures applications.
• Element in PASSIVE_TO_RUNNING_ERROR state: participant got error during configuration.
• Composition in PASSIVE_TO_RUNNING_ERROR state: at least one element is in PASSIVE_TO_RUNNING_ERROR state.
• Element in RUNNING state:
  • participant-ks8: applications are deployed (periodically checks if applications are running).
  • participant-policy: policy types are create in Api and deployed with Pap.
  • participant-http: applications are healthy and configured (periodically checks if applications are healthy).
• Composition in RUNNING state: all elements of a ACM are in RUNNING state, all applications are running.
• Element in RUN_ERROR state: participant got error during running state (it periodically checks if applications are running).
• Composition in RUN_ERROR state:  at least one element is in RUN_ERROR state
  • User could decide to move the composition from RUN_ERROR to PASSIVE state.
  • Application has been restarted by kubernetes, Participant detects that the application is running and move the element from  RUN_ERROR to RUNNING.
• User triggers to move the composition from RUNNING to PASSIVE: runtime-acm moves elements from RUNNING state to RUNNING_TO_PASSIVE.
• Element in RUNNING_TO_PASSIVE:
  • participant-ks8: do nothing
  • participant-policy: do nothing
  • participant-http: remove configuration
• Element in RUNNING_TO_PASSIVE_ERROR state: participant got error during removing configuration
• Composition in RUNNING_TO_PASSIVE_ERROR state: at least one element is in RUNNING_TO_PASSIVE_ERROR state.
• User triggers to move the composition from PASSIVE state to UNINITIALIZED: runtime-acm moves elements from PASSIVE state to PASSIVE_TO_UNINITIALIZED.
• Element in PASSIVE_TO_UNINITIALIZED:
  • participant-ks8: undeploys applications
  • participant-policy: undeploys policy types with Pap and deletes them in Api.
  • participant-http: do nothing
• Element in PASSIVE_TO_UNINITIALIZED_ERROR state: participant got error during undeployment
• Composition in PASSIVE_TO_UNINITIALIZED_ERROR state: at least one element is in PASSIVE_TO_UNINITIALIZED_ERROR state.
• Element in UNINITIALIZED state:
  • participant-ks8: applications are undeployed.
  • participant-policy: policy types are not deployed and not present in Api.
• In any Error status the User can re-try the operation.

Note:

Whit this solution, User can move from RUNNING to PASSIVE, update the service template related to the configuration (participant-http) when applications are still up, and after move from PASSIVE to RUNNING.

Second Proposed State Machine

...

• participant-ks8: deploys applications
• participant-policy: creates policy types in Api and deploys them with Pap.
• participant-http: configures applications.

...

• User can re-try UNINITIALIZED_TO_PASSIVE.
• User can go back to UNINITIALIZED.

...

• participant-ks8: applications are deployed.
• participant-policy: policy types are create in Api and deployed with Pap.
• participant-http: applications are configured.

...

• participant-ks8: starts monitoring if applications are running.
• participant-policy: do nothing (maybe starts monitoring if policy types are running).
• participant-http: starts monitoring if applications are healthy.

...

• participant-ks8: monitoring if applications are running.
• participant-policy: do nothing (maybe monitoring if policy types are running).
• participant-http: monitoring if applications are healthy.

...

ACM

...

Element

...

• User could decide to move the composition from RUN_ERROR to PASSIVE state.
• Application has been restarted by kubernetes, Participant detects that the application is running and move the element from  RUN_ERROR to RUNNING.

...

• participant-ks8: stop monitoring
• participant-policy: stop monitoring
• participant-http: stop monitoring

...

• participant-ks8: undeploys applications
• participant-policy: undeploys policy types with Pap and deletes them in Api.
• participant-http: do nothing

...

• participant-ks8: applications are undeployed.
• participant-policy: policy types are not deployed and not present in Api.

...

Note:

Whit this solution, User can move from RUNNING to PASSIVE, update the service template related to the configuration (participant-http) when applications are still up, and after move from PASSIVE to RUNNING.

ACM Element States in Participants

This section describes the state handling in ACM Elements in Participants

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