plant-description-management-idd-http-json.md

Plant Description Management HTTP(S)/JSON - Interface Design Description

Abstract

This document describes the HTTP/{TLS}/JSON variant of a service that can be used to manage Plant Descriptions in the Plant Description Engine core system.

Overview

This document describes the HTTP/{TLS}/JSON variant of the Plant Description Management (PDM) service, which allows for arbitrary Arrowhead Framework systems to manage Plant Descriptions in the Plant Description Engine (PDE) core system. Readers of this document are assumed to be familiar with the PDM service. For more information about the service, please refer to the service description document PDM. The rest of this document describes how to realize the PDM service using HTTP, optionally with TLS, and JSON, both in terms of its interfaces and its information model.

Service Interfaces

This section describes the interfaces that must be exposed by PDM services. In particular, the below subsection first names the HTTP method and path used to call the interface, after which it names an abstract interface from the PDM service description document, output type, as well as errors that can be thrown. The interface is expected to respond with HTTP status code 200 OK for all successful calls.

POST /{baseURI}/mgmt/pd

• Interface: AddPlantDescription
• Input: PlantDescription
• Output: PlantDescriptionEntry

Called to add a Plant Description to the PDE.

Example of valid invocation:

POST /pde/mgmt/pd HTTP/1.1
Accept: application/json
Content-Length: 2342
Content-Type: application/json

{
	"plantDescription": "ArrowHead core",
	"systems": [
		{
			"systemName": "serviceregistry",
			"systemId": "service_registry",
			"ports": [
				{ "portName": "service_registry", "serviceDefinition": "service-discovery"},
				{ "portName": "monitorable", "serviceDefinition": "monitorable"}
			]
		},
		{
			"systemName": "authorization",
			"systemId": "authorization",
			"ports": [
				{ "portName": "service_registry", "serviceDefinition": "service-discovery", "consumer": true },
				{ "portName": "tokenGeneration", "serviceDefinition": "token-generation"},
				{ "portName": "authorizationControl", "serviceDefinition": "authorization-control-intra"},
				{ "portName": "monitorable", "serviceDefinition": "monitorable"}
			]
		},
		{
			"systemName": "orchestration",
			"systemId": "orchestration",
			"ports": [
				{ "portName": "service_registry", "serviceDefinition": "service-discovery", "consumer": true },
				{ "portName": "tokenGeneration", "serviceDefinition": "token-generation", "consumer": true },
				{ "portName": "authorizationControl", "serviceDefinition": "authorization-control-intra", "consumer": true },
				{ "portName": "orchestrationService", "serviceDefinition": "orchestration-service"},
				{ "portName": "orchestrationStoreManagement", "serviceDefinition": "orchestration-store-management"},
				{ "portName": "orchestrationPush", "serviceDefinition": "orchestration-push", "consumer": true },
				{ "portName": "OrchestrationCapabilities", "serviceDefinition": "orchestration-capabilities", "consumer": true },
				{ "portName": "monitorable", "serviceDefinition": "monitorable"}
			]
		}
	],
	"connections": [
		{ "consumer": { "systemId": "authorization", "portName": "service_registry" },
		  "producer": { "systemId": "service_registry", "portName": "service_registry" }},
		{ "consumer": { "systemId": "orchestration", "portName": "service_registry" },
		  "producer": { "systemId": "service_registry", "portName": "service_registry" }},
		{ "consumer": { "systemId": "orchestration", "portName": "tokenGeneration" },
		  "producer": { "systemId": "authorization", "portName": "tokenGeneration" }},
		{ "consumer": { "systemId": "orchestration", "portName": "authorizationControl" },
		  "producer": { "systemId": "authorization", "portName": "authorizationControl" }}
	]
}

Example of valid response:

HTTP/1.1 200 OK
Content-Length: 2394
Content-Type: application/json

{
	"id": 1,
	"plantDescription": "ArrowHead core",
	"active": false,
	"systems": [
		{
			"systemName": "serviceregistry",
			"systemId": "service_registry",
			"ports": [
				{ "portName": "service_registry", "serviceDefinition": "service-discovery"}
				{ "portName": "monitorable", "serviceDefinition": "monitorable"}
			]
		},
		{
			"systemName": "authorization",
			"ports": [
				{ "portName": "service_registry", "serviceDefinition": "service-discovery", "consumer": true },
				{ "portName": "tokenGeneration", "serviceDefinition": "token-generation"},
				{ "portName": "authorizationControl", "serviceDefinition": "authorization-control-intra"}
				{ "portName": "monitorable", "serviceDefinition": "monitorable"}
			]
		},
		{
			"systemName": "orchestration",
			"systemId": "orchestration",
			"ports": [
				{ "portName": "service_registry", "serviceDefinition": "service-discovery", "consumer": true },
				{ "portName": "tokenGeneration", "serviceDefinition": "token-generation", "consumer": true },
				{ "portName": "authorizationControl", "serviceDefinition": "authorization-control-intra", "consumer": true },
				{ "portName": "orchestrationService", "serviceDefinition": "orchestration-service"},
				{ "portName": "orchestrationStoreManagement", "serviceDefinition": "orchestration-store-management"},
				{ "portName": "orchestrationPush", "serviceDefinition": "orchestration-push", "consumer": true },
				{ "portName": "OrchestrationCapabilities", "serviceDefinition": "orchestration-capabilities", "consumer": true }
				{ "portName": "monitorable", "serviceDefinition": "monitorable"}
			]
		}
	],
	"connections": [
		{ "consumer": { "systemId": "authorization", "portName": "service_registry" },
			"producer": { "systemId": "service_registry", "portName": "service_registry" }},
		{ "consumer": { "systemId": "orchestration", "portName": "service_registry" },
			"producer": { "systemId": "service_registry", "portName": "service_registry" }},
		{ "consumer": { "systemId": "orchestration", "portName": "tokenGeneration" },
			"producer": { "systemId": "authorization", "portName": "tokenGeneration" }},
		{ "consumer": { "systemId": "orchestration", "portName": "authorizationControl" },
			"producer": { "systemId": "authorization", "portName": "authorizationControl" }}
	],
	"createdAt": "2020-03-13T16:54:00.511Z",
	"updatedAt": "2020-03-13T16:54:00.511Z"
}

DELETE {baseURI}/mgmt/pd/{id}

• Interface: DeletePlantDescription

Called to delete the PlantDescriptionEntry specified by the id path parameter.

Example of valid invocation:

DELETE /pde/mgmt/pd/1 HTTP/1.1

Example of valid response:

HTTP/1.1 200 OK
Content-Length: 0

GET {baseURI}/mgmt/pd

• Interface: GetAllPlantDescriptions
• Output: PlantDescriptionEntryList

Called to acquire a list of Plant Description Entries present in the PDE.

Returns a list of Plant Description Entries. If page and item_per_page are not defined, returns all records.

Query params:

Field	Description	Mandatory
page	zero based page index	no
item_per_page	maximum number of items returned	no
sort_field	sorts by the given column	no
direction	direction of sorting	no
active	filter out active/inactive entries	no

Note: Default value for sort_field is id. All possible values are:

• id
• createdAt
• updatedAt

Note: Default value for direction is ASC. All possible values are:

• ASC
• DESC

Note: Possible values for active are true and false.

Example of valid invocation:

GET /pde/mgmt/pd HTTP/1.1
Accept: application/json

Example of valid response:

HTTP/1.1 200 OK
Content-Length: 2554
Content-Type: application/json

{
  "count": 1,
  "data": [
	{
		"id": 1,
		"plantDescription": "ArrowHead core",
		"active": false,
		"systems": [
			{
				"systemName": "serviceregistry",
				"systemId": "service_registry",
				"ports": [
					{ "portName": "service_registry", "serviceDefinition": "service-discovery"}
					{ "portName": "monitorable", "serviceDefinition": "monitorable"}
				]
			},
			{
				"systemName": "authorization",
				"systemId": "authorization",
				"ports": [
					{ "portName": "service_registry", "serviceDefinition": "service-discovery", "consumer": true },
					{ "portName": "tokenGeneration", "serviceDefinition": "token-generation"},
					{ "portName": "authorizationControl", "serviceDefinition": "authorization-control-intra"}
					{ "portName": "monitorable", "serviceDefinition": "monitorable"}
				]
			},
			{
				"systemName": "orchestration",
				"systemId": "orchestration",
				"ports": [
					{ "portName": "service_registry", "serviceDefinition": "service-discovery", "consumer": true },
					{ "portName": "tokenGeneration", "serviceDefinition": "token-generation", "consumer": true },
					{ "portName": "authorizationControl", "serviceDefinition": "authorization-control-intra", "consumer": true },
					{ "portName": "orchestrationService", "serviceDefinition": "orchestration-service"},
					{ "portName": "orchestrationStoreManagement", "serviceDefinition": "orchestration-store-management"},
					{ "portName": "orchestrationPush", "serviceDefinition": "orchestration-push", "consumer": true },
					{ "portName": "OrchestrationCapabilities", "serviceDefinition": "orchestration-capabilities", "consumer": true }
					{ "portName": "monitorable", "serviceDefinition": "monitorable"}
				]
			},
		],
		"connections": [
			{ "consumer": { "systemId": "authorization", "portName": "service_registry" },
			  "producer": { "systemId": "service_registry", "portName": "service_registry" }},
			{ "consumer": { "systemId": "orchestration", "portName": "service_registry" },
			  "producer": { "systemId": "service_registry", "portName": "service_registry" }},
			{ "consumer": { "systemId": "orchestration", "portName": "tokenGeneration" },
			  "producer": { "systemId": "authorization", "portName": "tokenGeneration" }},
			{ "consumer": { "systemId": "orchestration", "portName": "authorizationControl" },
			  "producer": { "systemId": "authorization", "portName": "authorizationControl" }}
		],
      "createdAt": "2020-03-13T16:54:00.511Z",
      "updatedAt": "2020-03-13T16:54:00.511Z"
	}
  ]
}

Get {baseURI}/mgmt/pd/{id}

• Interface: GetPlantDescription
• Output: PlantDescriptionEntry

Called to acquire the PlantDescriptionEntry specified by the id path parameter.

Example of valid invocation:

GET /pde/mgmt/pd/1 HTTP/1.1
Accept: application/json

Example of valid response:

HTTP/1.1 200 OK
Content-Length: 2460
Content-Type: application/json

{
	"id": 1,
	"plantDescription": "ArrowHead core",
	"active": false,
	"systems": [
		{
			"systemName": "serviceregistry",
			"systemId": "service_registry",
			"ports": [
				{ "portName": "service_registry", "serviceDefinition": "service-discovery"}
				{ "portName": "monitorable", "serviceDefinition": "monitorable"}
			]
		},
		{
			"systemName": "authorization",
			"systemNId": "authorization",
			"ports": [
				{ "portName": "service_registry", "serviceDefinition": "service-discovery", "consumer": true },
				{ "portName": "tokenGeneration", "serviceDefinition": "token-generation"},
				{ "portName": "authorizationControl", "serviceDefinition": "authorization-control-intra"}
				{ "portName": "monitorable", "serviceDefinition": "monitorable"}
			]
		},
		{
			"systemName": "orchestration",
			"systemId": "orchestration",
			"ports": [
				{ "portName": "service_registry", "serviceDefinition": "service-discovery", "consumer": true },
				{ "portName": "tokenGeneration", "serviceDefinition": "token-generation", "consumer": true },
				{ "portName": "authorizationControl", "serviceDefinition": "authorization-control-intra", "consumer": true },
				{ "portName": "orchestrationService", "serviceDefinition": "orchestration-service"},
				{ "portName": "orchestrationStoreManagement", "serviceDefinition": "orchestration-store-management"},
				{ "portName": "orchestrationPush", "serviceDefinition": "orchestration-push", "consumer": true },
				{ "portName": "OrchestrationCapabilities", "serviceDefinition": "orchestration-capabilities", "consumer": true }
				{ "portName": "monitorable", "serviceDefinition": "monitorable"}
			]
		}
	],
	"connections": [
		{ "consumer": { "systemId": "authorization", "portName": "service_registry" },
		  "producer": { "systemId": "service_registry", "portName": "service_registry" }},
		{ "consumer": { "systemId": "orchestration", "portName": "service_registry" },
		  "producer": { "systemId": "service_registry", "portName": "service_registry" }},
		{ "consumer": { "systemId": "orchestration", "portName": "tokenGeneration" },
		  "producer": { "systemId": "authorization", "portName": "tokenGeneration" }},
		{ "consumer": { "systemId": "orchestration", "portName": "authorizationControl" },
		  "producer": { "systemId": "authorization", "portName": "authorizationControl" }}
	],
  "createdAt": "2020-03-13T16:54:00.511Z",
  "updatedAt": "2020-03-13T16:54:00.511Z"
}

PUT /{baseURI}/mgmt/pd{id}

• Interface: ReplacePlantDescription
• Input: PlantDescription
• Output: PlantDescriptionEntry

Called to replace the Plant Description Entry specified by the id path parameter with the Plant Description in the PlantDescription parameter.

Example of valid invocation:

PUT /pde/mgmt/pd/1 HTTP/1.1
Accept: application/json
Content-Length: 2342
Content-Type: application/json

{
	"plantDescription": "ArrowHead core",
	"systems": [
		{
			"systemName": "serviceregistry",
			"systemId": "service_registry",
			"ports": [
				{ "portName": "service_registry", "serviceDefinition": "service-discovery"},
				{ "portName": "monitorable", "serviceDefinition": "monitorable"}
			]
		},
		{
			"systemName": "authorization",
			"systemId": "authorization",
			"ports": [
				{ "portName": "service_registry", "serviceDefinition": "service-discovery", "consumer": true },
				{ "portName": "tokenGeneration", "serviceDefinition": "token-generation"},
				{ "portName": "authorizationControl", "serviceDefinition": "authorization-control-intra"},
				{ "portName": "monitorable", "serviceDefinition": "monitorable"}
			]
		},
		{
			"systemName": "orchestration",
			"systemId": "orchestration",
			"ports": [
				{ "portName": "service_registry", "serviceDefinition": "service-discovery", "consumer": true },
				{ "portName": "tokenGeneration", "serviceDefinition": "token-generation", "consumer": true },
				{ "portName": "authorizationControl", "serviceDefinition": "authorization-control-intra", "consumer": true },
				{ "portName": "orchestrationService", "serviceDefinition": "orchestration-service"},
				{ "portName": "orchestrationStoreManagement", "serviceDefinition": "orchestration-store-management"},
				{ "portName": "orchestrationPush", "serviceDefinition": "orchestration-push", "consumer": true },
				{ "portName": "OrchestrationCapabilities", "serviceDefinition": "orchestration-capabilities", "consumer": true }
				{ "portName": "monitorable", "serviceDefinition": "monitorable"}
			]
		}
	],
	"connections": [
		{ "consumer": { "systemId": "authorization", "portName": "service_registry" },
		  "producer": { "systemId": "service_registry", "portName": "service_registry" }},
		{ "consumer": { "systemId": "orchestration", "portName": "service_registry" },
		  "producer": { "systemId": "service_registry", "portName": "service_registry" }},
		{ "consumer": { "systemId": "orchestration", "portName": "tokenGeneration" },
		  "producer": { "systemId": "authorization", "portName": "tokenGeneration" }},
		{ "consumer": { "systemId": "orchestration", "portName": "authorizationControl" },
		  "producer": { "systemId": "authorization", "portName": "authorizationControl" }}
	]
}

Example of valid response:

HTTP/1.1 200 OK
Content-Length: 2460
Content-Type: application/json

{
	"id": 1,
	"plantDescription": "ArrowHead core",
	"active": false,
	"systems": [
		{
			"systemName": "serviceregistry",
			"systemId": "service_registry",
			"ports": [
				{ "portName": "service_registry", "serviceDefinition": "service-discovery"}
				{ "portName": "monitorable", "serviceDefinition": "monitorable"}
			]
		},
		{
			"systemName": "authorization",
			"systemId": "authorization",
			"ports": [
				{ "portName": "service_registry", "serviceDefinition": "service-discovery", "consumer": true },
				{ "portName": "tokenGeneration", "serviceDefinition": "token-generation"},
				{ "portName": "authorizationControl", "serviceDefinition": "authorization-control-intra"}
				{ "portName": "monitorable", "serviceDefinition": "monitorable"}
			]
		},
		{
			"systemName": "orchestration",
			"systemId": "orchestration",
			"ports": [
				{ "portName": "service_registry", "serviceDefinition": "service-discovery", "consumer": true },
				{ "portName": "tokenGeneration", "serviceDefinition": "token-generation", "consumer": true },
				{ "portName": "authorizationControl", "serviceDefinition": "authorization-control-intra", "consumer": true },
				{ "portName": "orchestrationService", "serviceDefinition": "orchestration-service"},
				{ "portName": "orchestrationStoreManagement", "serviceDefinition": "orchestration-store-management"},
				{ "portName": "orchestrationPush", "serviceDefinition": "orchestration-push", "consumer": true },
				{ "portName": "OrchestrationCapabilities", "serviceDefinition": "orchestration-capabilities", "consumer": true },
				{ "portName": "monitorable", "serviceDefinition": "monitorable"}
			]
		}
	],
	"connections": [
		{ "consumer": { "systemId": "authorization", "portName": "service_registry" },
		  "producer": { "systemId": "service_registry", "portName": "service_registry" }},
		{ "consumer": { "systemId": "orchestration", "portName": "service_registry" },
		  "producer": { "systemId": "service_registry", "portName": "service_registry" }},
		{ "consumer": { "systemId": "orchestration", "portName": "tokenGeneration" },
		  "producer": { "systemId": "authorization", "portName": "tokenGeneration" }},
		{ "consumer": { "systemId": "orchestration", "portName": "authorizationControl" },
		  "producer": { "systemId": "authorization", "portName": "authorizationControl" }}
	],
  "createdAt": "2020-03-13T16:54:00.511Z",
  "updatedAt": "2020-03-13T17:44:00.511Z"
}

PATCH /{baseURI}/mgmt/pd/{id}

• Interface: UpdatePlantDescription
• Input: PlantDescriptionUpdate
• Output: PlantDescriptionEntry

Called to update the Plant Description Entry specified by the id path parameter with the information in the PlantDescriptionUpdate parameter.

Example of valid invocation:

PATCH /pde/mgmt/pd/1 HTTP/1.1
Accept: application/json
Content-Length: 23
Content-Type: application/json

{
	"active": true
}

Example of valid response:

HTTP/1.1 200 OK
Content-Length: 2459
Content-Type: application/json

{
	"id": 1,
	"plantDescription": "ArrowHead core",
	"active": true,
	"systems": [
		{
			"systemName": "serviceregistry",
			"systemId": "service_registry",
			"ports": [
				{ "portName": "service_registry", "serviceDefinition": "service-discovery"},
				{ "portName": "monitorable", "serviceDefinition": "monitorable"}
			]
		},
		{
			"systemName": "authorization",
			"systemId": "authorization",
			"ports": [
				{ "portName": "service_registry", "serviceDefinition": "service-discovery", "consumer": true },
				{ "portName": "tokenGeneration", "serviceDefinition": "token-generation"},
				{ "portName": "authorizationControl", "serviceDefinition": "authorization-control-intra"}
				{ "portName": "monitorable", "serviceDefinition": "monitorable"}
			]
		},
		{
			"systemName": "orchestration",
			"systemId": "orchestration",
			"ports": [
				{ "portName": "service_registry", "serviceDefinition": "service-discovery", "consumer": true },
				{ "portName": "tokenGeneration", "serviceDefinition": "token-generation", "consumer": true },
				{ "portName": "authorizationControl", "serviceDefinition": "authorization-control-intra", "consumer": true },
				{ "portName": "orchestrationService", "serviceDefinition": "orchestration-service"},
				{ "portName": "orchestrationStoreManagement", "serviceDefinition": "orchestration-store-management"},
				{ "portName": "orchestrationPush", "serviceDefinition": "orchestration-push", "consumer": true },
				{ "portName": "OrchestrationCapabilities", "serviceDefinition": "orchestration-capabilities", "consumer": true }
				{ "portName": "monitorable", "serviceDefinition": "monitorable"}
			]
		}
	],
	"connections": [
		{ "consumer": { "systemId": "authorization", "portName": "service_registry" },
		  "producer": { "systemId": "service_registry", "portName": "service_registry" }},
		{ "consumer": { "systemId": "orchestration", "portName": "service_registry" },
		  "producer": { "systemId": "service_registry", "portName": "service_registry" }},
		{ "consumer": { "systemId": "orchestration", "portName": "tokenGeneration" },
		  "producer": { "systemId": "authorization", "portName": "tokenGeneration" }},
		{ "consumer": { "systemId": "orchestration", "portName": "authorizationControl" },
		  "producer": { "systemId": "authorization", "portName": "authorizationControl" }}
	],
  "createdAt": "2020-03-13T16:54:00.511Z",
  "updatedAt": "2020-03-13T18:23:00.511Z"
}

Information model

Here, all data objects that can be part of PDM service calls are listed in alphabetic order. As a complement to the explicitly defined types in this section, there is also a list of implicit primitive types.

Connection

JSON object with the following fields:

Field	Type	Description	Mandatory	Default value
consumer	SystemPort	The consumer end SystemPort of the connection	true
producer	SystemPort	The producer end SystemPort of the connection	true
priority	Integer	Priority of the connection	false	null

PlantDescription

JSON object with the following fields:

Field	Type	Description	Mandatory	Default value
plantDescription	String	Plant description name	true
active	Boolean	Is this the active plant description	false	false
include	Array<Integer>	Array with Ids of other PDs that are included in this PD	false	[]
systems	Array<System>	Array with systems expected to be present in the plant	true
connections	Array<Connection>	Array with connection that should be populated into the Orchestrator	true

PlantDescriptionEntry

JSON object with the following fields:

Field	Type	Description	Mandatory	Default value
id	Integer	Id of the entry	true
plantDescription	String	Plant description name	true
active	Boolean	Is this the active plant description	true
include	Array<Integer>	Array with Ids of other PDs that are included in this PD	true
systems	Array<System>	Array with systems expected to be present in the plant	true
connections	Array<Connection>	Array with connection that should be populated into the Orchestrator	true
createdAt	DateTime	Creation date of the entry	true
updatedAt	DateTime	When the entry was last updated	true

PlantDescriptionEntryList

JSON object with the following fields:

Field	Type	Description	Mandatory	Default value
count	Integer	Number of records found	true
data	Array<PlantDescriptionEntry>	Array with Plant Description Entries	true

PlantDescriptionUpdate

JSON object with the following fields:

Currently only the following values can be updated. If a field is not present the current value will remain unchanged.

Field	Type	Description	Mandatory	Default value
plantDescription	String	Plant description name	false
active	Boolean	Is this the active plant description	false
include	Array<Integer>	Array with Ids of other PDs that are included in this PD	false
systems	Array<System>	Array with systems expected to be present in the plant	false
connections	Array<Connection>	Array with connection that should be populated into the Orchestrator	false

Port

JSON object with the following fields:

Field	Type	Description	Mandatory	Default value
portName	String	Identity of the port	true
serviceDefinition	String	Service definition identity	true
serviceInterface	String	Service interface	false	null
consumer	Boolean	Is the port a consumer port	false	false
metadata	Object<String>	Metadata - key-value pairs	false	null

System

JSON object with the following fields:

Field	Type	Description	Mandatory	Default value
systemId	String	Identity of the system within the PDE	true
systemName	String	Name of the system	false	null
metadata	Object<String>	Metadata - key-value pairs	false	null
ports	Array<Port>	Array with service ports exposed by the system	true

SystemPort

JSON object with the following fields:

Field	Type	Description	Mandatory	Default value
systemId	String	Identity of the system within the PDE	true
portName	String	Identity of the port	true

Primitives

As all messages are encoded using the JSON format, the following primitive constructs, part of that standard, become available. Note that the official standard is defined in terms of parsing rules, while this list only concerns syntactic information. Furthermore, the Object and Array types are given optional generic type parameters, which are used in this document to signify when pair values or elements are expected to conform to certain types.

JSON Type	Description
Value	Any out of Object, Array, String, Integer, Boolean or Null.
Object <A>	An unordered collection of [String: Value] pairs, where each Value conforms to type A. Empty objects are omitted.
Array <A>	An ordered collection of Value elements, where each element conforms to type A. Empty arrays are omitted.
String	An arbitrary UTF-8 string.
Integer	32-bit signed two's complement integer, which has a minimum value of -231 and a maximum value of 231-1
Boolean	One out of true or false.
Null	Must be null.

alias DateTime = String

Pinpoints a moment in time by providing a formatted string that conforms to the RFC 3339 specification, which could be regarded as a simplification of the ISO 8601 standard. Naively, the format could expressed as YYYY-MM-DDTHH:MM:SS.sssZ, where YYYY denotes year (4 digits), MM denotes month starting from 01, DD denotes day starting from 01, HH denotes hour in the 24-hour format (00-23), MM denotes minute (00-59), SS denotes second (00-59) and sss denotes second fractions (000-999). T is used as separator between the date and the time, while Z denotes the UTC time zone. At least three fraction digits should be used, which gives millisecond precision. An example of a valid date/time string is 2019-09-19T15:20:50.521Z. Other forms or variants, including the use of other time zones, is adviced against.