Replica support in Participant

In the current implementation, ACM supports multi-participant with same supported element Type but different participantId, so they need different properties file.

In order to support replica, it needs to support multi-participant using same properties file.

Note:

In a scenario of high number of compositions, if participant is restarting it will be slow-down the restarting action: AC-runtime will send a message for each composition primed and instance deployed to the participant.
To avoid the restarting action, participant needs a database support;
In a scenario where a participant is stuck in deploying, the instance will be in TIMEOUT and the user can take action like deploy again or undeploy. In that scenario the intermediary-participant has to receive the next message, kill the thread that is stuck in deploying and create a new thread.

Solution

Add dynamic participantId support and add database support,

Can a participant share the database with other replicas?

Shared database with same supported element Type: a composition will be connected to a specific participantId, so only one participant will do actions with this composition and his instances. But it can fetch all compositions that are sharing.
In a restarting scenario the participant will change the participantId, and it can still fetch compositions and instances. ACM-runtime decides who has to work with, and Participant will do actions based on the message.

Changes in Participant:

UUID participantId will be generated in memory instead to fetch it in properties file.
cosumerGroup will be empty (kafka configuration): any intermediary-participant will have unique Kafka queue, so they will receive same message that will be filtered by participantId.
Add client support for no-sql database.
Add no-sql database or mock for Unit Tests.
Refactor CacheProvider to support insert/update, intermediary-participant can still use the cache in memory.
Any new/change composition and instance will be saved in database.
Refactor Participants that are using own cache in memory (Policy Participant saves policy and policy type in memory)

Changes in ACM-runtime:

When participant go OFF_LINE:
- if there are compositions connected to that participant, ACM-runtime will find other ON_LINE participant with same supported element type;
- if other ON_LINE participant is present it will change the connection with all compositions and instance;
- after that, it will execute restart for all compositions and instances to the ON_LINE participant.
When receive a participant REGISTER:
- it will check if there are compositions connected to a OFF_LINE participant with same supported element type;
- if there are, it will change the connection with all compositions and instances to that new registered participant;
- after that it will execute restart for all compositions and instances changed.
- Refactor restarting scenario to apply the restarting only for compositions and instances in transition

Changes in docker/Kubernetes environment

Refactor CSIT to support no-sql database
Refactor performance and stability test to support no-sql database
Refactor OOM to support no-sql database

Database in Ericsson ADP marketplace

The no-sql database could be one that is already in ADP marketplace,

Distributed Coordinator ED (Etcd): Distributed systems use etcd as a consistent key-value store for configuration management, service discovery, and coordinating distributed work. Many organizations use etcd to implement production systems such as container schedulers, service discovery services, and distributed data storage.
Document Database PG (PostgreSql)
Key Value Database AG (Apache Geode): Apache Geode provides a database-like consistency model, reliable transaction processing and a shared-nothing architecture to maintain very low latency performance with high concurrency processing.(https://geode.apache.org/docs/guide/114/getting_started/intro_to_clients.html) or (https://docs.spring.io/spring-boot-data-geode-build/1.7.5/reference/html5/).
Key Value Database RD (Redis): RDB is NOT good if you need to minimize the chance of data loss in case Redis stops working.
Wide Column Database CD (Apache Cassandra)
Search Engine (Open Search): It supports Rest Api, https://opensearch.org/docs/latest/clients/java/

Open Search

Create a composition index

PUT https://{{address}}:9200/composition

{
  "settings": {
    "index": {
      "number_of_shards": 2,
      "number_of_replicas": 1
    }
  },
  "mappings": {
    "properties": {
      "id": {
        "type": "text"
      }
    }
  },
  "aliases": {
    "sample-alias1": {}
  }
}

Create a composition document

POST https://{{address}}:9200/composition/_doc/0da7f17d-68d4-47f3-9dbf-b380413c5fad

{
    "id": "0da7f17d-68d4-47f3-9dbf-b380413c5fad",
    "data": {
  "tosca_definitions_version": "tosca_simple_yaml_1_3",
  "data_types": {
    "onap.datatypes.ToscaConceptIdentifier": {
      "derived_from": "tosca.datatypes.Root",
      "properties": {
        "name": {
          "type": "string",
          "required": true
        },
        "version": {
          "type": "string",
          "required": true
        }
      }
    },
    "org.onap.datatypes.policy.clamp.acm.httpAutomationCompositionElement.RestRequest": {
      "version": "1.0.0",
      "derived_from": "tosca.datatypes.Root",
      "properties": {
        "restRequestId": {
          "type": "onap.datatypes.ToscaConceptIdentifier",
          "required": true,
          "description": "The name and version of a REST request to be sent to a REST endpoint"
        },
        "httpMethod": {
          "type": "string",
          "required": true,
          "constraints": [
            {
              "valid_values": [
                "POST",
                "PUT",
                "GET",
                "DELETE"
              ]
            }
          ],
          "description": "The REST method to use"
        },
        "path": {
          "type": "string",
          "required": true,
          "description": "The path of the REST request relative to the base URL"
        },
        "body": {
          "type": "string",
          "required": false,
          "description": "The body of the REST request for PUT and POST requests"
        },
        "expectedResponse": {
          "type": "integer",
          "required": true,
          "constraints": [],
          "description": "THe expected HTTP status code for the REST request"
        }
      }
    },
    "org.onap.datatypes.policy.clamp.acm.httpAutomationCompositionElement.ConfigurationEntity": {
      "version": "1.0.0",
      "derived_from": "tosca.datatypes.Root",
      "properties": {
        "configurationEntityId": {
          "type": "onap.datatypes.ToscaConceptIdentifier",
          "required": true,
          "description": "The name and version of a Configuration Entity to be handled by the HTTP Automation Composition Element"
        },
        "restSequence": {
          "type": "list",
          "entry_schema": {
            "type": "org.onap.datatypes.policy.clamp.acm.httpAutomationCompositionElement.RestRequest",
            "type_version": "1.0.0"
          },
          "description": "A sequence of REST commands to send to the REST endpoint"
        }
      }
    }
  },
  "node_types": {
    "org.onap.policy.clamp.acm.Participant": {
      "version": "1.0.1",
      "derived_from": "tosca.nodetypes.Root",
      "properties": {
        "provider": {
          "type": "string",
          "required": false
        }
      }
    },
    "org.onap.policy.clamp.acm.AutomationCompositionElement": {
      "version": "1.0.1",
      "derived_from": "tosca.nodetypes.Root",
      "properties": {
        "provider": {
          "type": "string",
          "required": false,
          "metadata": {
            "common": true
          },
          "description": "Specifies the organization that provides the automation composition element"
        },
        "startPhase": {
          "type": "integer",
          "required": false,
          "constraints": [
            {
              "greater_or_equal": 0
            }
          ],
          "metadata": {
            "common": true
          },
          "description": "A value indicating the start phase in which this automation composition element will be started, the first start phase is zero. Automation Composition Elements are started in their start_phase order and stopped in reverse start phase order. Automation Composition Elements with the same start phase are started and stopped simultaneously"
        },
        "uninitializedToPassiveTimeout": {
          "type": "integer",
          "required": false,
          "constraints": [
            {
              "greater_or_equal": 0
            }
          ],
          "default": 60,
          "metadata": {
            "common": true
          },
          "description": "The maximum time in seconds to wait for a state chage from uninitialized to passive"
        }
      }
    },
    "org.onap.policy.clamp.acm.AutomationComposition": {
      "version": "1.0.1",
      "derived_from": "tosca.nodetypes.Root",
      "properties": {
        "provider": {
          "type": "string",
          "required": false,
          "metadata": {
            "common": true
          },
          "description": "Specifies the organization that provides the automation composition element"
        },
        "elements": {
          "type": "list",
          "required": true,
          "metadata": {
            "common": true
          },
          "entry_schema": {
            "type": "onap.datatypes.ToscaConceptIdentifier"
          },
          "description": "Specifies a list of automation composition element definitions that make up this automation composition definition"
        }
      }
    },
    "org.onap.policy.clamp.acm.HttpAutomationCompositionElement": {
      "version": "1.0.0",
      "derived_from": "org.onap.policy.clamp.acm.AutomationCompositionElement",
      "properties": {
        "baseUrl": {
          "type": "string",
          "required": true,
          "description": "The base URL to be prepended to each path, identifies the host for the REST endpoints."
        },
        "httpHeaders": {
          "type": "map",
          "required": false,
          "entry_schema": {
            "type": "string"
          },
          "description": "HTTP headers to send on REST requests"
        },
        "configurationEntities": {
          "type": "map",
          "required": true,
          "entry_schema": {
            "type": "org.onap.datatypes.policy.clamp.acm.httpAutomationCompositionElement.ConfigurationEntity",
            "type_version": "1.0.0"
          },
          "description": "The connfiguration entities the Automation Composition Element is managing and their associated REST requests"
        }
      }
    }
  },
  "topology_template": {
    "node_templates": {
      "org.onap.policy.clamp.acm.HttpParticipant": {
        "version": "2.3.4",
        "type": "org.onap.policy.clamp.acm.Participant",
        "type_version": "1.0.1",
        "description": "Participant for Http requests",
        "properties": {
          "provider": "ONAP"
        }
      },
      "onap.policy.clamp.ac.element.Http_StarterAutomationCompositionElement": {
        "version": "1.2.3",
        "type": "org.onap.policy.clamp.acm.HttpAutomationCompositionElement",
        "type_version": "1.0.0",
        "description": "Automation composition element for the http requests of AC Element Starter microservice",
        "properties": {
          "provider": "ONAP",
          "uninitializedToPassiveTimeout": 180,
          "startPhase": 0
        }
      },
      "onap.policy.clamp.ac.element.Http_BridgeAutomationCompositionElement": {
        "version": "1.2.3",
        "type": "org.onap.policy.clamp.acm.HttpAutomationCompositionElement",
        "type_version": "1.0.0",
        "description": "Automation composition element for the http requests of AC Element Bridge microservice",
        "properties": {
          "provider": "ONAP",
          "uninitializedToPassiveTimeout": 180,
          "startPhase": 0
        }
      },
      "onap.policy.clamp.ac.element.Http_SinkAutomationCompositionElement": {
        "version": "1.2.3",
        "type": "org.onap.policy.clamp.acm.HttpAutomationCompositionElement",
        "type_version": "1.0.0",
        "description": "Automation composition element for the http requests of AC Element Sink microservice",
        "properties": {
          "provider": "ONAP",
          "uninitializedToPassiveTimeout": 180,
          "startPhase": 0
        }
      },
      "onap.policy.clamp.ac.element.AutomationCompositionDefinition": {
        "version": "1.2.3",
        "type": "org.onap.policy.clamp.acm.AutomationComposition",
        "type_version": "1.0.1",
        "description": "Automation composition for Demp",
        "properties": {
          "provider": "ONAP",
          "elements": [
            {
              "name": "onap.policy.clamp.ac.element.Http_StarterAutomationCompositionElement",
              "version": "1.2.3"
            },
            {
              "name": "onap.policy.clamp.ac.element.Http_BridgeAutomationCompositionElement",
              "version": "1.2.3"
            },
            {
              "name": "onap.policy.clamp.ac.element.Http_SinkAutomationCompositionElement",
              "version": "1.2.3"
            }
          ]
        }
      }
    }
  }
}
}

Fetch a composition

GET https://{{address}}:9200/composition/_doc/0da7f17d-68d4-47f3-9dbf-b380413c5fad