Release 4B 5

This page is part of the FHIR Specification (v4.3.0: R4B (v5.0.0: R5 - STU ). The This is the current published version which supercedes in it's permanent home (it will always be available at this version is 5.0.0 . URL). For a full list of available versions, see the Directory of published versions . Page versions: R5 R4B R5 R4B

2.47 2.13 Resource SubscriptionStatus - Content

FHIR Infrastructure icon Work Group Maturity Level : 0 2   Draft Trial Use Security Category : Business Compartments : Not linked to any No defined compartments

The SubscriptionStatus resource describes the state of a Subscription during notifications.

2.47.1 2.13.1 Scope and Usage

This document contains information about the SubscriptionStatus resource and details specific to options in it. It is defined as part of the topic-based model of See Subscriptions (Publish / Subscribe pattern). for general information about using Subscriptions in FHIR.

The SubscriptionStatus resource is used to convey information about the current state of a Subscription and the contents of a notification. Information contained within a SubscriptionStatus falls into three categories: Information to identify the relevant Subscription (e.g., a reference during client notifications. It is not persisted or allowed to a Subscription , SubscriptionTopic ) Information about the current state of the Subscription (e.g., Subscription status, number of events the Subscription has generated) Information about the current notification (e.g., notification type, the events in this notification) be referenced by other resources except as described below.

2.47.2 2.13.2 Boundaries and Relationships

The SubscriptionStatus resource is used in topic-based FHIR Subscriptions. This resource is designed only to be used to convey state information the Subscriptions Framework . Information about a subscription the Boundaries and notification during various operations, for example included with notifications or as Relationships both within the result Subscriptions Framework and to other areas of a status request. the FHIR specification can be found here .

2.47.3 2.13.3 References to this Resource

No resources refer to references for this resource directly. This resource does not implement any patterns. Resource.

2.47.4 2.13.4 Resource Content

Structure

Name Flags Card. Type Description & Constraints doco
. . SubscriptionStatus D TU DomainResource Status information about a Subscription provided during event notification
+ Rule: events listed in event Event notifications must contain events
+ Rule: Status messages must contain status

Elements defined in Ancestors: id , meta , implicitRules , language , text , contained , extension , modifierExtension
. . . status Σ C 0..1 code requested | active | error | off | entered-in-error
Binding: SubscriptionStatusCodes Subscription Status ( Required )
. . . type ?! Σ C 1..1 code handshake | heartbeat | event-notification | query-status | query-event
Binding: SubscriptionNotificationType Subscription Notification Type ( Required )
. . . eventsSinceSubscriptionStart Σ 0..1 string integer64 Events since the Subscription was created
. . . . eventNumber 1..1 string integer64 Event number Sequencing index of this event
. . . . timestamp 0..1 instant The instant this event occurred
. . . . focus 0..1 Reference ( Any ) The focus Reference to the primary resource or information of this event
. . . . additionalContext 0..* Reference ( Any ) Additional References related to the focus resource and/or context for of this event

. . . subscription Σ 1..1 Reference ( Subscription ) Reference to the Subscription responsible for this notification
. . . topic Σ 0..1 canonical ( SubscriptionTopic ) Reference to the SubscriptionTopic this notification relates to
. . . error Σ 0..* CodeableConcept List of errors on the subscription
Binding: Subscription Error Codes ( Example )


doco Documentation for this format icon

See the Extensions for this resource

UML Diagram ( Legend )

SubscriptionStatus ( DomainResource ) The status of the subscription, which marks the server state for managing the subscription status : code [0..1] « null (Strength=Required) SubscriptionStatusCodes ! » « This element has or is affected by some invariants C » The type of event being conveyed with this notificaiton notification (this element modifies the meaning of other elements) type : code [1..1] « null (Strength=Required) SubscriptionNotificationType ! » « This element has or is affected by some invariants C » The total number of actual events which have been generated since the Subscription was created (inclusive of this notification) - regardless of how many have been successfully communicated. This number is NOT incremented for handshake and heartbeat notifications eventsSinceSubscriptionStart : string integer64 [0..1] The reference to the Subscription which generated this notification subscription : Reference [1..1] « Subscription » The reference to the SubscriptionTopic for the Subscription which generated this notification topic : canonical [0..1] « SubscriptionTopic » A record of errors that occurred when the server processed a notification error : CodeableConcept [0..*] « null (Strength=Example) SubscriptionErrorCodes ?? » NotificationEvent The Either the sequential number of this event in this subscription context. Note that this value is a 64-bit integer value, encoded as context or a string relative event number for this notification eventNumber : string integer64 [1..1] The actual time this event occured occurred on the server timestamp : instant [0..1] The focus of this event. While this will usually be a reference to the focus resource of the event, it MAY contain a reference to a non-FHIR object focus : Reference [0..1] « Any » Additional context information for this event. Generally, this will contain references to additional resources included with the event (e.g., the Patient relevant to an Encounter), however it MAY refer to non-FHIR objects additionalContext : Reference [0..*] « Any » Detailed information about events relevant to this subscription notification notificationEvent [0..*]

XML Template

Turtle Template 

@prefix fhir: <http://hl7.org/fhir/> .doco


[ a fhir:SubscriptionStatus;
  fhir:nodeRole fhir:treeRoot; # if this is the parser root

  # from Resource: .id, .meta, .implicitRules, and .language
  # from DomainResource: .text, .contained, .extension, and .modifierExtension
  fhir:
  fhir:
  fhir:
  fhir:
    fhir:
    fhir:
    fhir:
    fhir:
  ], ...;
  fhir:
  fhir:
  fhir:

  fhir:status [ code ] ; # 0..1 I requested | active | error | off | entered-in-error
  fhir:type [ code ] ; # 1..1 I handshake | heartbeat | event-notification | query-status | query-event
  fhir:eventsSinceSubscriptionStart [ integer64 ] ; # 0..1 Events since the Subscription was created
  fhir:notificationEvent ( [ # 0..* I Detailed information about any events relevant to this notification
    fhir:eventNumber [ integer64 ] ; # 1..1 Sequencing index of this event
    fhir:timestamp [ instant ] ; # 0..1 The instant this event occurred
    fhir:focus [ Reference(Any) ] ; # 0..1 Reference to the primary resource or information of this event
    fhir:additionalContext  ( [ Reference(Any) ] ... ) ; # 0..* References related to the focus resource and/or context of this event
  ] ... ) ;
  fhir:subscription [ Reference(Subscription) ] ; # 1..1 Reference to the Subscription responsible for this notification
  fhir:topic [ canonical(SubscriptionTopic) ] ; # 0..1 Reference to the SubscriptionTopic this notification relates to
  fhir:error  ( [ CodeableConcept ] ... ) ; # 0..* List of errors on the subscription

]

Changes since from both R4 and R4B

This resource did not exist in Release 3 R4

See the Full Difference for further information

This analysis is available for R4 as XML or JSON . Conversions between R3 and R4 for R4B as XML or JSON .

Structure

Name Flags Card. Type Description & Constraints doco
. . SubscriptionStatus D TU DomainResource Status information about a Subscription provided during event notification
+ Rule: events listed in event Event notifications must contain events
+ Rule: Status messages must contain status

Elements defined in Ancestors: id , meta , implicitRules , language , text , contained , extension , modifierExtension
. . . status Σ C 0..1 code requested | active | error | off | entered-in-error
Binding: SubscriptionStatusCodes Subscription Status ( Required )
. . . type ?! Σ C 1..1 code handshake | heartbeat | event-notification | query-status | query-event
Binding: SubscriptionNotificationType Subscription Notification Type ( Required )
. . . eventsSinceSubscriptionStart Σ 0..1 string integer64 Events since the Subscription was created
. . . . eventNumber 1..1 string integer64 Event number Sequencing index of this event
. . . . timestamp 0..1 instant The instant this event occurred
. . . . focus 0..1 Reference ( Any ) The focus Reference to the primary resource or information of this event
. . . . additionalContext 0..* Reference ( Any ) Additional References related to the focus resource and/or context for of this event

. . . subscription Σ 1..1 Reference ( Subscription ) Reference to the Subscription responsible for this notification
. . . topic Σ 0..1 canonical ( SubscriptionTopic ) Reference to the SubscriptionTopic this notification relates to
. . . error Σ 0..* CodeableConcept List of errors on the subscription
Binding: Subscription Error Codes ( Example )


doco Documentation for this format icon

See the Extensions for this resource

UML Diagram ( Legend )

SubscriptionStatus ( DomainResource ) The status of the subscription, which marks the server state for managing the subscription status : code [0..1] « null (Strength=Required) SubscriptionStatusCodes ! » « This element has or is affected by some invariants C » The type of event being conveyed with this notificaiton notification (this element modifies the meaning of other elements) type : code [1..1] « null (Strength=Required) SubscriptionNotificationType ! » « This element has or is affected by some invariants C » The total number of actual events which have been generated since the Subscription was created (inclusive of this notification) - regardless of how many have been successfully communicated. This number is NOT incremented for handshake and heartbeat notifications eventsSinceSubscriptionStart : string integer64 [0..1] The reference to the Subscription which generated this notification subscription : Reference [1..1] « Subscription » The reference to the SubscriptionTopic for the Subscription which generated this notification topic : canonical [0..1] « SubscriptionTopic » A record of errors that occurred when the server processed a notification error : CodeableConcept [0..*] « null (Strength=Example) SubscriptionErrorCodes ?? » NotificationEvent The Either the sequential number of this event in this subscription context. Note that this value is a 64-bit integer value, encoded as context or a string relative event number for this notification eventNumber : string integer64 [1..1] The actual time this event occured occurred on the server timestamp : instant [0..1] The focus of this event. While this will usually be a reference to the focus resource of the event, it MAY contain a reference to a non-FHIR object focus : Reference [0..1] « Any » Additional context information for this event. Generally, this will contain references to additional resources included with the event (e.g., the Patient relevant to an Encounter), however it MAY refer to non-FHIR objects additionalContext : Reference [0..*] « Any » Detailed information about events relevant to this subscription notification notificationEvent [0..*]

Turtle Template 

@prefix fhir: <http://hl7.org/fhir/> .doco


[ a fhir:SubscriptionStatus;
  fhir:nodeRole fhir:treeRoot; # if this is the parser root

  # from Resource: .id, .meta, .implicitRules, and .language
  # from DomainResource: .text, .contained, .extension, and .modifierExtension
  fhir:
  fhir:
  fhir:
  fhir:
    fhir:
    fhir:
    fhir:
    fhir:
  ], ...;
  fhir:
  fhir:
  fhir:

  fhir:status [ code ] ; # 0..1 I requested | active | error | off | entered-in-error
  fhir:type [ code ] ; # 1..1 I handshake | heartbeat | event-notification | query-status | query-event
  fhir:eventsSinceSubscriptionStart [ integer64 ] ; # 0..1 Events since the Subscription was created
  fhir:notificationEvent ( [ # 0..* I Detailed information about any events relevant to this notification
    fhir:eventNumber [ integer64 ] ; # 1..1 Sequencing index of this event
    fhir:timestamp [ instant ] ; # 0..1 The instant this event occurred
    fhir:focus [ Reference(Any) ] ; # 0..1 Reference to the primary resource or information of this event
    fhir:additionalContext  ( [ Reference(Any) ] ... ) ; # 0..* References related to the focus resource and/or context of this event
  ] ... ) ;
  fhir:subscription [ Reference(Subscription) ] ; # 1..1 Reference to the Subscription responsible for this notification
  fhir:topic [ canonical(SubscriptionTopic) ] ; # 0..1 Reference to the SubscriptionTopic this notification relates to
  fhir:error  ( [ CodeableConcept ] ... ) ; # 0..* List of errors on the subscription

]

Changes since Release 4 from both R4 and R4B

This resource did not exist in Release 3 R4

See the Full Difference for further information

This analysis is available for R4 as XML or JSON . Conversions between R3 and R4 for R4B as XML or JSON .

 

See the Profiles & Extensions and the alternate Additional definitions: Master Definition XML + JSON , XML Schema / Schematron + JSON Schema , ShEx (for Turtle ) + see the extensions , the spreadsheet version & the dependency analysis

2.47.4.1 2.13.4.1 Terminology Bindings

Path Definition ValueSet Type Reference Documentation
SubscriptionStatus.status SubscriptionStatusCodes (a valid code from Subscription Status ) Required SubscriptionStatusCodes

State values for FHIR Subscriptions.

SubscriptionStatus.type SubscriptionNotificationType Required SubscriptionNotificationType

The type of notification represented by the status message.

SubscriptionStatus.error SubscriptionErrorCodes Example SubscriptionErrorCodes

Codes to represent subscription error details

2.47.4.2 2.13.4.2 Constraints

id UniqueKey Level Location Description Expression
sst-1 img  sst-1 Rule (base) events listed in event Event notifications must contain events type (type = 'event-notification' or type = 'query-event') implies (notificationEvent.exists() and notificationEvent.first().exists()) notificationEvent.exists()
img  sst-2 Rule (base) Status messages must contain status type = 'query-status' implies status.exists()

2.47.5 2.13.5 Timing and Currency

This resource is used to communicate information about a Subscription and the events represented by a notification bundle. The process of sending a notification (e.g., a notification this status is included with) can change the status of that subscription. Servers SHALL populate elements with the most recent information at the time of generation (e.g., when a notification is created) and receivers SHOULD be aware that this information might not be current at the time a notification is processed (e.g., a subscription was active but has subsequently moved to an error state).

2.47.6 2.13.6 Content and PHI

Subscription notifications MAY contain PHI. Applications are responsible for following FHIR security guidance and compliance with relevant security requirements (e.g., corporate policy, government regulation, etc.). Hinting for the allowed amount of PHI is available in the relevant Subscription resource, via the channel and payload information.

Since Subscription Topic definitions contain human-readable descriptions and definitions, the purpose of a topic may be understood by viewing the resource. Given that canonical links to topics are intended to be resolvable and/or searchable (e.g., indexed in a registry), it is assumed that anyone with a link to a topic also knows what that topic is about. Thus, topics MAY be considered PHI and SHOULD be reviewed before inclusion in a notification.

Hinting about when a canonical topic URL may be included with a notification can be derived from a subscription's payload level. E.g.:

  • empty : SHOULD NOT be present
  • id-only : MAY be present
  • full-resource : SHOULD be present

2.13.7 Event Numbering

Since this specification does not currently define any channel types that guarantee client receipt of notifications, a monotonically-increasing event number is critical to detecting several classes of delivery errors (more information is available at Detecting Delivery Errors ). However, with the availability of custom-defined channels , notifications can be sent across channels that provide guaranteed delivery (e.g., a message queue), which removes the need for global tracking of event numbers.

For channels that do not need event numbers, it is still desireable for clients to have an index for the events present in a notification. In all cases, a value for SubscriptionStatus.notificationEvent.eventNumber is required - either the number in-sequence based on the total number of events on a subscription or a notification-bundle relative index (e.g., 1, 2, 3, etc.).

Element Delivery Type Optionality Notes
SubscriptionStatus.eventsSinceSubscriptionStart Best Effort Required Servers SHALL include this value when sending event notifications in order to allow clients to detect missing events.
This value is inclusive of this notification (e.g., the first event notification sent would include one (1) in this element).
SubscriptionStatus.eventsSinceSubscriptionStart Guaranteed Optional Servers MAY include this value when sending event notifications.
SubscriptionStatus.notificationEvent.eventNumber Best Effort Required Event numbers SHALL match the index in the subscription event sequence. E.g., the highest-numbered event in the notification will match the number in eventsSinceSubscriptionStart .
SubscriptionStatus.notificationEvent.eventNumber Guaranteed Required A relative index of events in a single notification, e.g., 1, 2, 3, etc..

2.47.7 2.13.8 Notification Types

This specification describes five distinct outbound notification types: Event , Handshake , Heartbeat , Query Status , and Query Event . For each, the notification body is a subscription-notification Bundle with a SubscriptionStatus resource used to convey Subscription and notification details.

2.47.7.1 2.13.8.1 Event Notification

The primary notification bundle type is a notification about an event.

Element Optionality Notes
SubscriptionStatus.status Recommended Current status of the relevant subscription (e.g., active ).
SubscriptionStatus.type Required SHALL be event-notification
SubscriptionStatus.eventsSinceSubscriptionStart Required Special Servers SHALL include this value when sending event notifications in order to allow clients to detect missing events. This value is inclusive of this notification (e.g., the first event notification sent would include one (1) in this element). Required for subscriptions with best-effort delivery, optional for subscriptions with guaranteed delivery. See Event Numbering for details.
SubscriptionStatus.notificationEvent Required For notifications that include events, this element SHALL be present. Details about specific elements within this structure are included in this table.
SubscriptionStatus.notificationEvent.eventNumber Required Special This element is mandatory if a notificationEvent is present. Required for subscriptions with best-effort delivery, optional for subscriptions with guaranteed delivery. See Event Numbering for details.
SubscriptionStatus.notificationEvent.timestamp Recommended So that clients can discover when an event actually occurred, timestamp is recommended.
SubscriptionStatus.notificationEvent.focus Special Links contained in the focus element contain resource IDs, so will or will not be present based on the payload level relevant to the notification:
  • empty : SHALL NOT be present
  • id-only : SHALL be present
  • full-resource : SHALL be present
Note that servers SHOULD include the Reference.type element if if the type is not specified in Reference.reference
SubscriptionStatus.notificationEvent.additionalContext Special Links contained in the additionalContext element contain resource IDs and MAY or MAY not exist. Presence is determined based on the payload level relevant to the notification, if they are available:
  • empty : SHALL NOT be present
  • id-only : SHOULD be present
  • full-resource : SHOULD be present
Note that servers SHOULD include the Reference.type element if if the type is not specified in Reference.reference
SubscriptionStatus.topic Optional See Content and PHI .

2.47.7.2 2.13.8.2 Handshake Notification

When a connection to an Endpoint is established or re-established, a server MAY send a Handshake notification to the endpoint.

The client expectations upon receipt of a Handshake notification differ for each channel type (e.g., for the rest-hook channel type, a client endpoint responds to event notifications with standard HTTP response codes).

Element Optionality Notes
SubscriptionStatus.status Recommended Current status of the relevant subscription (e.g., active ).
SubscriptionStatus.type Required SHALL be handshake
SubscriptionStatus.eventsSinceSubscriptionStart Optional For a new Subscription, if this value is present it SHALL be zero (0).
A sender MAY send a handshake with a non-zero number of events, for example as process for re-establishing communication after an error state.
Note: this value SHALL NOT be incremented by sending a handshake notification.
SubscriptionStatus.notificationEvent Special A server MAY include historical events for a client with a handshake , if any exist. For example, during a reconnection process, a server MAY opt to include all events since the last successful transmission to the client. Details about specific elements within this structure are included in this table.
SubscriptionStatus.notificationEvent.eventNumber Special This element is mandatory if a notificationEvent is present. Required for subscriptions with best-effort delivery, optional for subscriptions with guaranteed delivery. See Event Numbering for details.
SubscriptionStatus.notificationEvent.timestamp Special If a server is including prior events, timestamp is recommended, so that clients can process historical events with proper context.
SubscriptionStatus.notificationEvent.focus Special Links contained in the focus element contain resource IDs, so will or will not be present based on the payload level relevant to the notification:
  • empty : SHALL NOT be present
  • id-only : SHALL be present if a notificationEvent is included
  • full-resource : SHALL be present if a notificationEvent is present
Note that servers SHOULD include the Reference.type element if if the type is not specified in Reference.reference
SubscriptionStatus.notificationEvent.additionalContext Special Links contained in the additionalContext element contain resource IDs and MAY or MAY not exist. Presence is determined based on the payload level relevant to the notification, if they are available:
  • empty : SHALL NOT be present
  • id-only : SHOULD be present if a notificationEvent is present
  • full-resource : SHOULD be present if a notificationEvent is present
Note that servers SHOULD include the Reference.type element if if the type is not specified in Reference.reference
SubscriptionStatus.topic Optional See Content and PHI .

The client is not expected to take any special action in receipt of a Handshake notification beyond the channel-specific requirement for receiving an event notification.

2.47.7.3 2.13.8.3 Heartbeat Notification

A heartbeat notification is a subscription-notification Bundle of type heartbeat sent without incrementing the subscription event count, though servers MAY include the most recent event in the notification. For servers, heartbeat notifications allow systems to ensure that the connection is still alive and valid. For clients, heartbeat notifications serve as a method to detect errors in communication. Note that a client is not required to take any action in receipt of a heartbeat beyond the channel-specific requirement for receiving an event notification (e.g., accepting the notification bundle with an HTTP 200).

Heartbeat intervals are negotiated while creating a Subscription. If accepted, servers SHOULD send one heartbeat per interval on the accepted subscription.

Element Optionality Notes
SubscriptionStatus.status Recommended Current status of the relevant subscription (e.g., active ).
SubscriptionStatus.type Required SHALL be heartbeat
SubscriptionStatus.eventsSinceSubscriptionStart Recommended The presence of this value allows clients to detect missing notifications. Recommended for subscriptions with best-effort delivery, optional for subscriptions with guaranteed delivery.
Note: this value SHALL NOT be incremented by sending a heartbeat notification.
SubscriptionStatus.notificationEvent Special A server MAY include historical events for a client with a heartbeat , if any exist. For example, a server MAY opt to include the most recent event since the last successful transmission to the client. Details about specific elements within this structure are included in this table.
SubscriptionStatus.notificationEvent.eventNumber Special This element is mandatory if If a notificationEvent server is present. including any prior events, this element is required for subscriptions with best-effort delivery and optional for subscriptions with guaranteed delivery. See Event Numbering for details.
SubscriptionStatus.notificationEvent.timestamp Special If a server is including any prior events, timestamp is recommended, so that clients can process historical events with proper context.
SubscriptionStatus.notificationEvent.focus Special Links contained in the focus element contain resource IDs, so will or will not be present based on the payload level relevant to the notification:
  • empty : SHALL NOT be present
  • id-only : SHALL be present if a notificationEvent is included
  • full-resource : SHALL be present if a notificationEvent is present
Note that servers SHOULD include the Reference.type element if if the type is not specified in Reference.reference
SubscriptionStatus.notificationEvent.additionalContext Special Links contained in the additionalContext element contain resource IDs and MAY or MAY not exist. Presence is determined based on the payload level relevant to the notification, if they are available:
  • empty : SHALL NOT be present
  • id-only : SHOULD be present if a notificationEvent is present
  • full-resource : SHOULD be present if a notificationEvent is present
Note that servers SHOULD include the Reference.type element if if the type is not specified in Reference.reference
SubscriptionStatus.topic Optional See Content and PHI .

2.47.7.4 2.13.8.4 Query Status

Clients can ask a server at any time for the current status of a Subscription, for example via the $status operation .

Since the $status operation is part of the FHIR REST API, the guidance below assumes that a user has been authenticated and is allowed access to all relevant resources.

Element Optionality Notes
SubscriptionStatus.status Required Current status of the relevant subscription (e.g., active ).
SubscriptionStatus.type Required SHALL be query-status
SubscriptionStatus.eventsSinceSubscriptionStart Required Special This value is required Required for clients to know if there are missing notifications. subscriptions with best-effort delivery, optional for subscriptions with guaranteed delivery. See Event Numbering for details.
Note: this value SHALL NOT be incremented by sending a query-status notification.
SubscriptionStatus.notificationEvent Prohibited Special A query-status notification SHALL NOT MAY contain any event information. recent notifications.
SubscriptionStatus.topic Recommended See Content and PHI , but note that guidance will vary since there is an active user session.

2.47.7.5 2.13.8.5 Query Event

Some servers may allow clients to ask for events which have already occurred. Notification bundles returned by such operations or queries should use occurred, for example via the $events operation .

Since the query-event $events type. operation is part of the FHIR REST API, the guidance below assumes that a user has been authenticated and the server has filtered any results according to what the user is allowed access.

Element Optionality Notes
SubscriptionStatus.status Recommended Current status of the relevant subscription (e.g., active ).
SubscriptionStatus.type Required SHALL be query-event .
SubscriptionStatus.eventsSinceSubscriptionStart Recommended This value is allows clients to know if they are missing notifications. Recommended for subscriptions with best-effort delivery and optional for subscriptions with guaranteed delivery.
Note: this value SHALL NOT be incremented by sending a query-event bundle.
See Event Numbering for more information.
SubscriptionStatus.notificationEvent Required For notifications that include events, this element SHALL be present. Details about specific elements within this structure are included in this table.
SubscriptionStatus.notificationEvent.eventNumber Required Special This element is mandatory if a notificationEvent is present. Required for subscriptions with best-effort delivery, optional for subscriptions with guaranteed delivery. See Event Numbering for details.
SubscriptionStatus.notificationEvent.timestamp Recommended So that clients can discover when an event actually occurred, timestamp is recommended.
SubscriptionStatus.notificationEvent.focus Special Links contained in the focus element contain resource IDs, so will or will not be present based on the payload level relevant to the notification:
  • empty : SHALL NOT be present
  • id-only : SHALL be present
  • full-resource : SHALL be present
Note that servers SHOULD include the Reference.type element if if the type is not specified in Reference.reference
SubscriptionStatus.notificationEvent.additionalContext Special Links contained in the additionalContext element contain resource IDs and MAY or MAY not exist. Presence is determined based on the payload level relevant to the notification, if they are available:
  • empty : SHALL NOT be present
  • id-only : SHOULD be present
  • full-resource : SHOULD be present
Note that servers SHOULD include the Reference.type element if if the type is not specified in Reference.reference
SubscriptionStatus.topic Recommended See Content and PHI , but note that guidance will vary since there is an active user session.

2.47.8 2.13.9 Notifications and Errors

If a server encounters errors while sending a notification, the server may retry the notification a fixed number of times and/or refer errors to its own alert logs. If the notification fails, the server SHOULD set the status of the subscription to error . If the error would be useful to a client (e.g., notification failed because the destination SSL certificate expired), servers SHOULD track errors and provide details to the client. If a notification retry attempt succeeds, the server SHOULD update the status to active and MAY remove any error codes. If a subscription fails consistently a server may choose set the subscription status to The off SubscriptionStatus and stop trying to send notifications. Errors a server wishes to make accessible to clients are stored resource is key in Subscription.error . Servers should provide a mechanism for clearing detecting various errors (e.g., when resetting a Subscription.status back to requested after an error). Since Subscription.error represents server errors, a server SHOULD NOT allow clients to add errors. 2.47.8.1 Detecting Delivery Errors There are several mechanisms available to subscribers in order to understand the current state of notification delivery. Below are some example error scenarios with details about how a subscriber can detect the problem state. 2.47.8.1.1 Missing Event The diagram below shows how a subscriber can use the SubscriptionStatus.eventsSinceSubscriptionStart parameter on received notifications to determine that an event has been missed. Diagram showing a missed-event detection communication and recovery workflow In the above sequence, the subscriber tracks the eventsSinceSubscriptionStart of each received notification (per Subscription). When the subscriber received event 23, the subscriber was aware that the last notification it received was a single notification for event 21. The subscriber then waited an amount of time to ensure that event 22 was indeed missing (and not, for example, still being processed) processing. For more information, see Managing Subscriptions and started a recovery process. The recovery process itself will vary by subscriber, but should be a well-understood method for recovering in the event of errors. 2.47.8.1.2 Broken Communication Errors The diagram below show how a subscriber can use a subscription heartbeat period to determine errors which prevent notifications from reaching the endpoint. Diagram showing broken communication detection and recovery workflow In the above sequence, the subscriber is aware that in the heartbeatPeriod has elapsed for a subscription without receiving any notifications. . Subscriptions Framework page.

2.47.8.1.3 2.13.10 Recovering from Errors Search Parameters

Clients are responsible for devising an appropriate method Search parameters for recovering from errors. Often, this process will include a series or batch of requests that allow a client to know resource. See also the current state or a request to an $events operation when available. For example, an application may need to query all relevant resources full list of search parameters for a patient in order to ensure nothing has been missed. Once an application has returned to a functional state, it should request the subscription is reactivated by updating the status to either requested or active as appropriate. 2.47.8.1.4 Using this resource , and check the $events operation Extensions registry Servers MAY choose to support the $events operation defined for search parameters on the Subscription extensions related to this resource. The $events operation allows clients to request events which have occurred common parameters also apply. See Searching for more information about searching in the past. Servers which implement the operation MAY use implementation-specific criteria to restrict availability of events (e.g., most recent 10 events, events within the past 30 days, etc.). REST, messaging, and services.

During a recovery process, clients MAY try to retrieve missing events via the $events operation, which should allow processing to continue as normal. (No search parameters for this resource)