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qmf.opcode field | Message Body Data Type | Sent By | Sent To | Description |
---|---|---|---|---|
_exception | QMF_DATA | Agent | reply-to | This general-purpose message can be sent by an agent in response to any request (query, subscription, method) if the request could not be completed for any reason. The QMF_DATA in the message body contains details of why the failure occurred. |
_agent_locate_request | QMF_QUERY_PREDICATE | Console | QMF Topic | A console may send an agent-locate-request in order to reach all available agents. The predicate may be used to limit the set of agents that will respond to the request. |
_agent_locate_response | QMF_DATA | Agent | reply-to | This is a response to an agent-locate-request. An agent will send an agent-locate-response if it received an agent-locate-request with a predicate that matches its characteristics. |
_agent_heartbeat_indication | QMF_DATA | Agent | Topic | Each agent periodically sends a heartbeat message to a topic to indicate that it is alive and connected. The content of the heartbeat message is the list of the agent's characteristics. |
_query_request | defined by qmf.content (either QMF_QUERY or QMF_V1_QUERY) | Console | Agent | A console sends a query to an agent to request that the agent send data to the requester. |
_query_response | List of <qmf.content> | Agent | reply-to | The response to a query sent by a console. |
_subscribe_request | QMF_SUBSCRIBE | Console | Agent | A console sends a subscribe-request to an agent to receive data matched by a query. A subscription differs from a query request in that it continues to send updated information to the console when the data changes. |
_subscribe_response | QMF_SUBSCRIPTION | Agent | reply-to | When an agent receives a subscribe-request, it sends a subscribe-response granting (or refusing) the subscription. Should the subscription succeed, the response will contain an identifier for the subscription assigned by the Agent. Thereafter, it will send data-indication messages on the same correlation-id with updates when they happen or periodically. The first data-indication message sent by the agent will contain all matching data, subsequent data-indications will contain only those matching data that has changed since the last update. |
_subscribe_cancel_indication | QMF_SUBSCRIPTION_ID | Console | Agent | A console can request that a subscription it created be immediately cancelled. This message must have the same correlation-id as the original request, and contain the subscription identifier as assigned by the Agent. |
_subscribe_refresh_indication | QMF_SUBSCRIPTION_ID | Console | Agent | A console can keep a subscription alive by periodically refreshing it by sending a subscribe-refresh-indication. This message must have the same correlation-id as the original request, and contain the subscription identifier as assigned by the Agent. |
_data_indication | List of <qmf.content> | Agent | reply-to or topic | A data indication is sent by an Agent when 1) subscription data has changed and needs to be published, 2) an event has occurred and event data is being published, and 3) any other time an agent wants to send unsolicited data. |
_method_request | QMF_METHOD_CALL | Console | Agent | A console may invoke a method on an object managed by an agent. It may also invoke a method directly on the agent if appropriate. This message contains the method call including the input arguments. |
_method_response | QMF_METHOD_RESULT | Agent | reply-to | A method call always results in a single method result. This message carries either the output arguments from a successful method call or it holds an exception to describe a failure. |
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qmf.content field | Data Type | Description | |||
---|---|---|---|---|---|
_schema_package | STRING | Schema package name | |||
_schema_id | SCHEMA_ID | Schema class identifier | |||
_schema_class | SCHEMA_CLASS | Schema class definition | |||
_object_id | OBJECT_ID | Managed object identifier | |||
_data | QMF_DATA | Data, managed and/or described or free-form | |||
_event | QMF_EVENT | Event | |||
_query | QMF_QUERY | QMFv2 Query | _query_v1 | QMF_V1_QUERY | Query map from the QMFv1 Specification |
Message Body Map Formats
SCHEMA_ID
...
No Format |
---|
QMF_QUERY := { _what: QMF_CONTENT_TYPE, _where: QMF_QUERY_PREDICATE } |
Field | Optional | Description |
---|---|---|
_what | no | Identifies the kind of data being queried |
_where | yes | Query predicate to limit the number of results of the query |
QMF_V1_QUERY
No Format |
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QMF_V1_QUERY := { _class: STRING,_id: STRING | SCHEMA_ID | OBJECT_ID _package: STRING, _objectid: STRING } |
...
Field
...
Optional
...
Description
...
_class
...
yes
...
Identifies the class of the objects being queried (i.e. return all objects of this class).
...
_package
...
yes
...
Identifies the package in which the class is defined. If this field is specified, the _class field must also be specified. This field serves to disambiguate the request in case there are multiple packages that contain a class of the same name.
...
_objectid
...
yes
...
}
|
Field | Optional | Description |
---|---|---|
_what | no | Identifies the kind of data being queried |
_where | yes | Query predicate to limit the number of results of the query |
_id | yes | (Alternative to _where) This identifier indicates which single item the query is looking for. If the content-type in _what is: |
QMF_CONTENT_TYPE
No Format |
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QMF_CONTENT_TYPE := { _agent: VOID }
:= { _schema_id: VOID }
:= { _schema: VOID }
:= { _object_id: VOID | SCHEMA_ID }
:= { _object: VOID | SCHEMA_ID }
|
QMF_QUERY_PREDICATE
QMF_SUBSCRIBE
No Format |
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QMF_SUBSCRIBE := { _query: QMF_QUERY, _duration: NUMBER, _interval: NUMBER } |
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