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.

  • 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