13.2.2. Monitor Service Topics

The following table depicts the properties of the topics within the Monitor Service:

Topic name	Topic Alias	TopicDataType
fastdds_monitor_service_status	MONITOR_SERVICE_TOPIC	Monitor Service Status Data

13.2.2.1. Monitor Service Status Topic

The Monitor Service Status Topic carries information about the monitoring information of the local entities of a particular DomainParticipant. The monitoring information can be divided into different statuses identified by a StatusKind. The possible values are described in the following table:

Value	Name	Description
0	ProxyInfo	Collection of Parameters describing the Proxy Data of that entity
1	ConnectionList	List of connections that this entity is using with its matched remote entities.
2	IncompatibleQoSInfo	Status of the Incompatible QoS of that entity.
3	InconsistentTopicInfo	Status of Inconsistent topics that the topic of that entity has.
4	LivelinessLostInfo	Tracks the status of the number of times a writer lost liveliness.
5	LivelinessChangedInfo	Tracks the status of the number of times the liveliness changed in a reader.
6	DeadlineMissedInfo	The Status of the number of deadlines missed of a sample for that entity.
7	SampleLostInfo	Tracks the status of the number of times this entity lost samples.

Note

If the service is enabled in a RTPS layer context, not all the statuses will be published, only the ProxyInfo and ConnectionList.

The Monitor Service Status Topic publishes new data when new updates are received from any of the DomainParticipant’s local entities (on-event driven) with a minimum waiting time between publications. In addition, it is in charge of notifying about any disposal or liveliness lost.

13.2.2.1.1. Monitor Service Status Data

The MonitorServiceStatusData data structure comprises the following fields:

• local_entity: Guid_t of the local entity.

• status_kind: StatusKind enumeration identifying the status.

• value: The value of the status.

MonitorServiceStatusData
  @Key GUID local_entity
  @Key StatusKind status_kind
  Data value

Note

The local_entity and status_kind are keyed fields, hence making use of instances (see Topics, keys and instances). In this case, the pair <local_entity, status_kind> identifies a unique instance.

Each of the StatusKind enumeration values maps to a corresponding Data value. The actual field names for the different values are described below:

• entity_proxy: Collection of the serialized Quality of Service Parameters in the form of a ParameterList.

• connection_list: Defines how is this entity communicating with its matched entities. Each of the elements is of Connection type (depicted below).

Connection
  uint32_t mode //INTRAPROCESS, DATASHARING, TRANSPORT
  LocatorList announced_locators
  LocatorList used_locators

• incompatible_qos_status: Status of the Incompatible QoS of that entity.

  • DataWriter Incompatible QoS Offered.

  • DataReader Incompatible QoS Requested.

• inconsistent_topic_status: Status of Inconsistent topics of the topic of that entity. Asked to the topic of the requested entity.

• liveliness_lost_status: Tracks the status of the number of times that liveliness was lost by a DataWriter.

• liveliness_changed_status: Tracks the status of the number of times that liveliness was lost by a DataReader.

• deadline_status: The Status of the number of deadlines missed that were registered in that entity.

• sample_lost_status: The number of samples that entity lost.

The following table depicts the relation between each of the StatusKind values and the Data field:

StatusKind Value	StatusKind Name	Data field Name	IDL Data field Type
0	ProxyInfo	entity_proxy	sequence<octet>
1	ConnectionList	connection_list	sequence<Connection>
2	IncompatibleQoSInfo	incompatible_qos_status	IncompatibleQoSStatus
3	InconsistentTopicInfo	inconsistent_topic_status	InconsistentTopicStatus
4	LivelinessLostInfo	liveliness_lost_status	LivelinessLostStatus
5	LivelinessLostInfo	liveliness_changed_status	LivelinessChangedStatus
6	DeadlineMissedInfo	deadline_missed_status	DeadlineMissedStatus
7	SampleLostInfo	sample_lost_status	SampleLostStatus