Add documentation for error handling in ACM participants

[policy/parent.git] / docs / clamp / acm / acm-participant-guide.rst

diff --git a/docs/clamp/acm/acm-participant-guide.rst b/docs/clamp/acm/acm-participant-guide.rst
index b2ee244..c5623b2 100755 (executable)
--- a/docs/clamp/acm/acm-participant-guide.rst
+++ b/docs/clamp/acm/acm-participant-guide.rst
@@ -92,6 +92,7 @@ AutomationCompositionElementListener:
   8. void deprime(UUID compositionId) throws PfModelException;
   9. void handleRestartComposition(UUID compositionId, List<AutomationCompositionElementDefinition> elementDefinitionList, AcTypeState state) throws PfModelException;
   10. void handleRestartInstance(UUID automationCompositionId, AcElementDeploy element, Map<String, Object> properties, DeployState deployState, LockState lockState) throws PfModelException;
+  11. void migrate(UUID instanceId, AcElementDeploy element, UUID compositionTargetId, Map<String, Object> properties) throws PfModelException;
 
 These method from the interface are implemented independently as per the user requirement. These methods after handling the
 appropriate requests should also invoke the intermediary's publisher apis to notify the ACM-runtime with the acknowledgement events.
@@ -133,13 +134,39 @@ This following method is invoked to update the AC element state after each opera
 
 In/Out composition Properties
 -----------------------------
-  The 'Common Properties' could be created or updated by ACM-runtime. Participants will receive that Properties during priming events.
+The 'Common Properties' could be created or updated by ACM-runtime.
+Participants will receive that Properties during priming events.
 
-  The 'Out Properties' could be created or updated by participants. ACM-runtime will receive that Properties during ParticipantStatus event.
-  The participant can trigger this event using the method sendAcDefinitionInfo.
+.. code-block:: java
 
-  Is allowed to the participant to read all In/Out Properties of all compositions handled by the participant using the method getAcElementsDefinitions.
-  The following code is an example how to update the property 'myProperty' and send to ACM-runtime:
+  @Override
+  public void prime(UUID compositionId, List<AutomationCompositionElementDefinition> elementDefinitionList) throws PfModelException {
+      for (var acElementDefinition : elementDefinitionList) {
+          var inProperties = acElementDefinition.getAutomationCompositionElementToscaNodeTemplate().getProperties();
+          .......
+      }
+      .......
+  }
+
+The 'Common Properties' could be fetched during depriming events.
+
+.. code-block:: java
+
+  @Override
+  public void deprime(UUID compositionId) throws PfModelException {
+      var elementDefinitionList = intermediaryApi.getAcElementsDefinitions(compositionId);
+      for (var acElementDefinition : elementDefinitionList.values()) {
+          var inProperties = acElementDefinition.getAutomationCompositionElementToscaNodeTemplate().getProperties();
+          .......
+      }
+      .......
+  }
+ 
+The 'Out Properties' could be created or updated by participants. ACM-runtime will receive that Properties during ParticipantStatus event.
+The participant can trigger this event using the method sendAcDefinitionInfo.
+
+Is allowed to the participant to read all In/Out Properties of all compositions handled by the participant using the method getAcElementsDefinitions.
+The following code is an example how to update the property 'myProperty' and send to ACM-runtime:
 
 .. code-block:: java
 
@@ -353,6 +380,21 @@ The following example shows the Handler implementation and how could be the impl
         }
     }
 
+    @Override
+    public void migrate(UUID automationCompositionId, AcElementDeploy element, UUID compositionTargetId,
+            Map<String, Object> properties) throws PfModelException {
+
+        // TODO migrate process
+
+        if (isMigrateSuccess()) {
+            intermediaryApi.updateAutomationCompositionElementState(automationCompositionId, element.getId(),
+                    DeployState.DEPLOYED, null, StateChangeResult.NO_ERROR, "Migrated");
+        } else {
+            intermediaryApi.updateAutomationCompositionElementState(automationCompositionId, element.getId(),
+                    DeployState.DEPLOYED, null, StateChangeResult.FAILED, "Migrate failed!");
+        }
+    }
+
     @Override
     public void prime(UUID compositionId, List<AutomationCompositionElementDefinition> elementDefinitionList)
             throws PfModelException {
@@ -441,3 +483,42 @@ The following example shows the Handler implementation and how could be the impl
     }
 
 
+AC Element states in failure scenarios
+--------------------------------------
+
+During the execution of any state change order, there is always a possibility of failures or exceptions that can occur in the participant.
+This can be tackled by the followed approaches.
+
+The participant implementation can handle the exception and revert back the appropriate AC element state, by invoking the
+'updateAutomationCompositionElementState' api from the participant intermediary.
+
+Alternatively, the participant can simply throw a PfModelException from its implementation which will be handled by the participant intermediary.
+The intermediary handles this exception and rolls back the AC element to its previous state with the appropriate stateChange Result.
+Please refer the following table for the state change reversion that happens in the participant intermediary for the AC elements.
+
+================== ==================
+**Error Scenario** **State Reverted**
+================== ==================
+Prime fails        Commissoned
+
+Deprime fails      Primed
+
+Deploy fails       Undeployed
+
+Undeploy fails     Deployed
+
+Update fails       Deployed
+
+Delete fails       Undeployed
+
+Lock fails         Unlocked
+
+Unlock fails       Locked
+================== ==================
+
+Considering the above mentioned behavior of the participant Intermediary, it is the responsibility of the developer to tackle the
+error scenarios in the participant with the suitable approach.
+
+Tips:
+If the participant tries to undeploy an element which doesn’t exist in the system any more (due to various other external factors),
+it could update the element state to ‘undeployed’ using the Intermediary api.
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