Microservice Architecture

This section helps you to understand the microservices architecture of Temenos.

Interaction Framework receives requests from a variety of channels. It analyses if the request has to be processed in microservice or Temenos Transact.

  • If the Interaction Framework sends the request to Temenos Transact, the request is processed in Temenos Transact, sent to Ingesters (which is in microservices) and then saved in database.
  • If the Interaction Framework sends the request to microservices, the request is processed in microservices and gets saved in database.

Temenos microservices architecture is given below.

Event Driven Architecture

It supports implementing an Inbox or Outbox pattern in the microservice framework to ensure messages are processed and the state changed appropriately within the underlying transaction. It is required to implement as a library, which can be re-used across microservices and Temenos products. This library standardizes the Inbox and Outbox implementations in the respective product solutions to support commands.

Where, Commands and Events are first-class entities in the applications and each command or event should be unique across the applications.

ClosedFeatures

The Event Driven architecture features are:

ClosedAt-least-once Delivery

The outbox infrastructure guarantees At-least-once Delivery of the events generated from the application. Outbox also provides the capability for the application to raise events to the Target Topic in Streaming platform based on the configuration in the Application.

ClosedIdempotency

Messages need a unique message reference, if not supplied this is created - identify messages uniquely and then retry or de-duplicate as appropriate.

ClosedEvent Atomicity

Events must be atomic with business transactions.

Inbox or Outbox pattern ensures messages are processed and the state changed appropriately with the underlying transaction. Inbox Outbox functionality has been implemented as a generic infrastructure java library that is re-used across micro-services.

ClosedEvent-Based Interactions - Scale

The following are the characteristics of even-based interactions.

  • Asynchronous – Event-based architectures are asynchronous without blocking. This allows resources to move freely to the next task once their unit of work is complete, without worrying about what happened before or will happen next. They also allow events to be queued or buffered which prevents consumers from putting back pressure on producers or blocking them.
  • Loose Coupling – Services do not need knowledge of (or dependencies) on other services. When using events, services operate independently, without knowledge of other services, including their implementation details and transport protocol. Services under an event model can be updated, tested, and deployed independently and more easily.
  • Easy Scaling – As the services are decoupled under an event-driven architecture and they perform only one task, it is easy to track down bottlenecks to a specific service and scale the service.
  • Recovery Support – An event-driven architecture with a queue can recover lost work by replaying events from the past to prevent data loss when a consumer needs to recover.
ClosedDesign

The below diagram highlights the components of Inbox and outbox components used to support Event-based architecture. The Inbox processor helps the application to receive commands/Events and invoke appropriate business implementation.

ClosedInbox

It helps application to guarantee idempotency by identifying command or event uniquely and handle duplicates using Inbox infrastructure.

  • Pulling from a queue or invoked directly from HTTP as a Lambda function, etc.
  • Write to the inbox table and commit to the queue with the unique message reference, handle de-duplication check here.
  • The long-running thread takes un-processed messages and invokes micro-service logic.
  • When the micro-service logic completes AND as part of the same database transaction, flag the message as processed. Some sort of locking/status updates to show the message is being processed. Also, dead letter queue processing to pick up messages flagged as being processed but timed out, e.g. the processing thread has died.
  • Clean up a process to purge messages that have been processed.

The event store guarantees event ordering and non-duplication of events in a single place. History/audit log and allows replay and catch-up.

ClosedOutbox

Outbox component helps application to raise business events and System Events for any API or command executed in the Microservice application. The Outbox design guarantees "Atleast Once delivery" of the Event messages from the application. Each of the Events raised from the application adheres the business Event or System Events Schema.

ClosedCommand

A command is a request on microservice to perform a business function in the context of the specific microservice. The microservice framework provides an infrastructure command ingester that receives all command events and routes it to the respective business command implementation. Existing business operation (OPERATION ID) that is designed using Open API (swagger) in a microservice is automatically enabled for Event-based execution.

A command event with a unique id (UUID) issued by the client application is performed only once.

ClosedBusiness Events

Businesses Events may demand microservice to publish a particular business updates or state changes to other applications.

EXAMPLE: The execution of the " Payment order creation command event " in Payment service may raise the "Payment order Accepted" business event, the Booking service consumes this event, and updates the booking status as Confirmed.
ClosedSystem Events

System events are infrastructure events raised by the microservice framework to represent the command flow.

ClosedSample Data

Event Type

 Types Schema

Sample

Command Event

   CreateNewPaymentOrder_CommandEvent.json

CreateNewPaymentOrder_CommandEvent_Sample.json

Business Event

   CreatePaymentEvent_BusinessEvent.json

CreatePaymentEvent_BusinessEvent.json

System Event

 CommandReceived Event CreateNewPaymentOrder_CommandReceivedEvent.json

CreateNewPaymentOrder_CommandReceivedEvent_Sample.json

System Event

 CommandProcessed Event PaymentStatus_CommandProcessedEvent.json

PaymentStatus_CommandProcessedEvent_Sample.json

System Event

 CommandFailed Event CommandFailedEvent.json

CommandFailedEvent_Sample.json

NOTE: Command Received events are disabled by default.

Configurations

This section provides the implementation details on the inbox and outbox component in Microservices.

ClosedPackaged Libraries

Following are the java libraries provides inbox and outbox implementation for the applications.

Closedms-commons-connect.jar

Commons Connect library helps to deliver the outbox messages to the queue/topic. Kafka and Kinesis producers are used to deliver the messages to Kafka/Kinesis topic.

ms-commons-connect depends on DES library to instantiate kafka/kinesis producer.

Closedms-inbox-outbox.jar

Inbox outbox library helps to implement the Inbox/Outbox pattern in the application. It defines the standard set of interfaces to implement and configure the ms-inbox-outbox and depends on ms-commons-connect to deliver the messages.

Using Inbox Outbox library

Procedure:

  1. Create inbox and outbox table (refer database schema below).
  2. Create inbox and outbox entity java which should implement the interface: com.temenos.inboxoutbox.data.InboxEvent/OutboxEvent.
  3. Implement the interface InboxDao and OutboxDao.
  4. Configure the implementation class in the environment properties class.inbox.dao and class.outbox.dao (refer below).
  5. Instantiate an entity and call InboxFunction/OutboxFunction to save the inbox/outbox.
ClosedEvent Schema

The events that support inbox and outbox need to adhere to the following schema.

ClosedBusiness Events

Business events are raised from the microservices to notify about the state change happened inside business transactions. Subscribers get notification for these business events and handle them. Example events: PaymentOrderCreated, FundsReserved, MoneyMoved, etc.

ClosedFundsReserved_Schema.txt 
{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "type": "object",
  "properties": {
    "eventId": {
      "type": "string"
    },
    "dateTime": {
      "type": "integer"
    },
    "organizationId": {
      "type": "null"
    },
    "correlationId": {
      "type": "string"
    },
    "tenantId": {
      "type": "null"
    },
    "userId": {
      "type": "null"
    },
    "priority": {
      "type": "integer"
    },
    "status": {
      "type": "string"
    },
    "businessObjects": {
      "type": "null"
    },
    "eventType": {
      "type": "string"
    },
    "operationInstanceId": {
      "type": "null"
    },
    "payload": {
      "type": "object",
      "properties": {
        "transactionId": {
          "type": "string"
        },
        "accountId": {
          "type": "string"
        },
        "amount": {
          "type": "integer"
        },
        "processedDateTime": {
          "type": "integer"
        },
        "status": {
          "type": "string"
        }
      },
      "required": [
        "transactionId",
        "accountId",
        "amount",
        "processedDateTime",
        "status"
      ]
    },
    "sequenceInstanceId": {
      "type": "null"
    }
  },
  "required": [
    "eventId",
    "dateTime",
    "correlationId",
    "eventType",
    "payload"
  ]
}
ClosedCommand

Command events are the system events produced by the individual microservice to notify that it receives and processes the Command or Event.

ClosedCommandReceived_schema.txt 
{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "type": "object",
  "properties": {
    "eventId": {
      "type": "string"
    },
    "dateTime": {
      "type": "integer"
    },
    "organizationId": {
      "type": "string"
    },
    "correlationId": {
      "type": "string"
    },
    "tenantId": {
      "type": "string"
    },
    "userId": {
      "type": "string"
    },
    "priority": {
      "type": "integer"
    },
    "status": {
      "type": "string"
    },
    "eventType": {
      "type": "string"
    },
    "payload": {
      "type": "object",
      "properties": {
        "eventId": {
          "type": "string"
        },
        "dateTime": {
          "type": "integer"
        },
        "organizationId": {
          "type": "string"
        },
        "correlationId": {
          "type": "string"
        },
        "tenantId": {
          "type": "string"
        },
        "userId": {
          "type": "string"
        },
        "priority": {
          "type": "integer"
        },
        "status": {
          "type": "string"
        },
        "businessObjects": {
          "type": "string"
        },
        "eventType": {
          "type": "string"
        },
        "operationInstanceId": {
          "type": "string"
        },
        "payload": {
          "type": "object",
          "properties": {
            "body": {
              "type": "object",
              "properties": {
                "debitAccountId": {
                  "type": "string"
                },
                "amount": {
                  "type": "string"
                },
                "creditAccountId": {
                  "type": "string"
                }
              },
              "required": [
                "debitAccountId",
                "amount",
                "creditAccountId"
              ]
            }
          },
          "required": [
            "body"
          ]
        },
        "sequenceInstanceId": {
          "type": "string"
        }
      },
      "required": [
        "eventId",
        "dateTime",
        "organizationId",
        "correlationId",
        "tenantId",
        "userId",
        "priority",
        "status",
        "businessObjects",
        "eventType",
        "operationInstanceId",
        "payload",
        "sequenceInstanceId"
      ]
    }
  },
  "required": [
    "eventId",
    "dateTime",
    "correlationId",
    "eventType",
    "payload"
  ]
}
ClosedCommandProcessed_Schema.txt 
{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "type": "object",
  "properties": {
    "eventId": {
      "type": "string"
    },
    "dateTime": {
      "type": "integer"
    },
    "organizationId": {
      "type": "string"
    },
    "correlationId": {
      "type": "string"
    },
    "tenantId": {
      "type": "string"
    },
    "userId": {
      "type": "string"
    },
    "priority": {
      "type": "integer"
    },
    "status": {
      "type": "string"
    },
    "businessObjects": {
      "type": "string"
    },
    "eventType": {
      "type": "string"
    },
    "operationInstanceId": {
      "type": "string"
    },
    "payload": {
      "type": "object",
      "properties": {
        "commandId": {
          "type": "string"
        },
        "operationInstanceId": {
          "type": "string"
        },
        "sequenceInstanceId": {
          "type": "string"
        },
        "eventType": {
          "type": "string"
        },
        "status": {
          "type": "string"
        },
        "businessObject": {
          "type": "object",
          "properties": {
            "status": {
              "type": "integer"
            },
            "failureMessages": {
              "type": "array",
              "items": {}
            },
            "body": {
              "type": "object",
              "properties": {
                "id": {
                  "type": "string"
                },
                "debitAccountId": {
                  "type": "string"
                },
                "amount": {
                  "type": "integer"
                },
                "creditAccountId": {
                  "type": "string"
                },
                "fundsRersavationId": {
                  "type": "string"
                },
                "paymentorderRequestId": {
                  "type": "string"
                }
              },
              "required": [
                "id",
                "debitAccountId",
                "amount",
                "creditAccountId",
                "fundsRersavationId",
                "paymentorderRequestId"
              ]
            },
            "success": {
              "type": "boolean"
            }
          },
          "required": [
            "status",
            "failureMessages",
            "body",
            "success"
          ]
        }
      },
      "required": [
        "commandId",
        "operationInstanceId",
        "sequenceInstanceId",
        "eventType",
        "status",
        "businessObject"
      ]
    },
    "sequenceInstanceId": {
      "type": "string"
    }
  },
  "required": [
    "eventId",
    "dateTime",
    "correlationId",
    "eventType",
    "payload"
  ]
}
ClosedCommandFailed_Schema.txt 
{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "type": "object",
  "properties": {
    "eventId": {
      "type": "string"
    },
    "dateTime": {
      "type": "integer"
    },
    "organizationId": {
      "type": "string"
    },
    "correlationId": {
      "type": "string"
    },
    "tenantId": {
      "type": "string"
    },
    "userId": {
      "type": "string"
    },
    "priority": {
      "type": "integer"
    },
    "status": {
      "type": "string"
    },
    "eventType": {
      "type": "string"
    },
    "payload": {
      "type": "object",
      "properties": {
        "commandId": {
          "type": "string"
        },
        "operationInstanceId": {
          "type": "string"
        },
        "sequenceInstanceId": {
          "type": "string"
        },
        "eventType": {
          "type": "string"
        },
        "status": {
          "type": "string"
        },
        "businessObject": {
          "type": "object",
          "properties": {
            "status": {
              "type": "integer"
            },
            "failureMessages": {
              "type": "array",
              "items": [
                {
                  "type": "object",
                  "properties": {
                    "message": {
                      "type": "string"
                    },
                    "code": {
                      "type": "string"
                    }
                  },
                  "required": [
                    "message",
                    "code"
                  ]
                }
              ]
            },
            "body": {
              "type": "string"
            },
            "success": {
              "type": "boolean"
            }
          },
          "required": [
            "status",
            "failureMessages",
            "body",
            "success"
          ]
        }
      },
      "required": [
        "commandId",
        "operationInstanceId",
        "sequenceInstanceId",
        "eventType",
        "status",
        "businessObject"
      ]
    }
  },
  "required": [
    "eventId",
    "dateTime",
    "correlationId",
    "eventType",
    "payload"
  ]
}

Command

Description

correlationId

Unique identifier (UUID) holds the incoming message identifier.

dateTime

Stores the event creation date time

eventId

Unique identifier (UUID)

eventType

Event Type – <MS_NAME>.<Operation>

operationInstanceId

Operation ID of the sequence

organizationId

Organization Id 

payload

Event data payload

priority

Event Priority for delivery 

SequenceInstanceId

Sequence id of this event belongs to

tenantId

Tenant Id

userId

User Id
ClosedEnvironmental Parameters

Inbox Outbox:

  • class.inbox.dao - Implementation of InboxDao interface.
  • class.outbox.dao - Implementation of OutboxDao interface.

MS Framework:

  • temn.msf.raise.received.event: "false"/"true" (whether to raise commandReceived event)
  • temn.msf.exec.env: server/serverless (onPremise/cloud deployment)
ClosedDatabase Schema

The following are the database tables to be created and made available in the application schema. The database can be SQL or NOSQL.

ClosedInbox Schema

 Column 

Data Type

Description

 Mandatory (M)/

Optional (O)

tenantId

Text

 Tenant Id

O

organizationId

Text 

Organization Id 

M

eventId

Text

Unique identifier (UUID)

M

userId

Text

User Id

M

priority

 integer

Event Priority for delivery 

O

eventType

Text

Event Type – used to identify the event type

M

eventDetails

Text

Additional Event metadata (as name-value pair)

O

payload

Text

Event data payload

M

status

Text

Possible Values “NEW”, PROCESSED”, “FAILED”

M

creationTime

TimeStamp

Stores the event creation date-time

M

processedTime

TimeStamp

Event processed date time

<yet to be implemented>

M
ClosedOutbox Schema

 Column

Data Type

 Description

 Mandatory (M)/

Optional (O)

tenantId

Text

 Tenant Id of optional

O

organizationId

Text

Organization Id

M

eventId

Text

Unique identifier (UUID)

M

correlationId

Text

Unique identifier (UUID)

O

userId

Text

User Id

M

priority

 integer

Event Priority for delivery

O

eventType

Text

Event Type – used to identify the event type

M

eventDetails

Text

Additional Event metadata (as name-value pair)

O

businessKey

Text

business record key

O

payload

Text

Event data payload

M

status

Text

Possible Values “NEW”, DELIVERED”, “FAILED”

M

creationTime

TimeStamp

Stores the event creation date-time

M

processedTime

TimeStamp

Event processed date time

<yet to be implemented>

M
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Published on :
Wednesday, October 12, 2022 6:49:16 PM IST

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