1.7. Get entity meta information¶
Fast DDS Statistics Backend includes the possibility of retrieving the meta information of any given entity present
in the network.
The returned tree always includes the basic information about the entity: kind, id, name, alias and
if the entity is alive.
Depending on the EntityKind, the returned object can contain extra information such as pid, guid, qos,
locators or data_type.
get_info() returns a Info object.
Info host_info = StatisticsBackend::get_info(host_id);
Info user_info = StatisticsBackend::get_info(user_id);
Info process_info = StatisticsBackend::get_info(process_id);
Info locator_info = StatisticsBackend::get_info(locator_id);
Info domain_info = StatisticsBackend::get_info(domain_id);
Info participant_info = StatisticsBackend::get_info(participant_id);
Info datareader_info = StatisticsBackend::get_info(datareader_id);
Info datawriter_info = StatisticsBackend::get_info(datawriter_id);
Info topic_info = StatisticsBackend::get_info(topic_id);
1.7.1. Host Info example¶
{
"id": 1,
"kind": "host",
"name": "host_name",
"alias": "host_alias",
"alive": true,
"metatraffic": false,
"status": "OK"
}
1.7.2. User Info example¶
{
"id": 2,
"kind": "user",
"name": "user_name",
"alias": "user_alias",
"alive": true,
"metatraffic": false,
"status": "OK"
}
1.7.3. Process Info example¶
{
"id": 3,
"kind": "process",
"name": "process_name",
"alias": "process_alias",
"alive": true,
"metatraffic": false,
"status": "OK",
"pid": "9564"
}
1.7.4. Locator Info example¶
{
"id": 4,
"kind": "locator",
"name": "127.0.0.1:7412",
"alias": "localhost",
"alive": true,
"metatraffic": false,
"status": "OK"
}
1.7.5. Domain Info example¶
{
"id": 0,
"kind": "domain",
"name": "0",
"alias": "domain_alias",
"alive": true,
"metatraffic": false,
"status": "OK"
}
1.7.6. Participant Info example¶
{
"id": 5,
"kind": "participant",
"name": "participant_name",
"alias": "participant_alias",
"alive": true,
"metatraffic": false,
"status": "OK",
"guid": "01.0f.22.cd.59.64.04.00.05.00.00.00|00.00.01.c1",
"qos": {
"available_builtin_endpoints": 3135,
"lease_duration":
{
"nanoseconds": 0,
"seconds": 3
},
"properties":
[
{
"name": "PARTICIPANT_TYPE",
"value": "CLIENT"
},
{
"name": "DS_VERSION",
"value": "2.0"
}
],
"user_data": "656e636c6176653d2f3b00",
"vendor_id": "010f"
},
"app_id": "SHAPES_DEMO",
"locators":
[
"127.0.0.1:1234"
]
}
1.7.7. DataReader Info example¶
{
"id": 6,
"kind": "datareader",
"name": "datareader_name",
"alias": "datareader_alias",
"alive": false,
"metatraffic": false,
"status": "OK",
"guid": "01.0f.22.cd.59.64.04.00.05.00.00.00|00.00.01.04",
"qos":
{
"data_sharing":
{
"domain_ids":
[
0
],
"kind": "AUTO",
"max_domains": 1,
"shm_directory": "/dev/shm"
},
"deadline":
{
"period":
{
"nanoseconds": 50,
"seconds": 10
}
},
"destination_order":
{
"kind": "BY_RECEPTION_TIMESTAMP_DESTINATIONORDER_QOS"
},
"disable_positive_acks":
{
"duration":
{
"nanoseconds": 100,
"seconds": 0
},
"enabled": true
},
"durability":
{
"kind": "VOLATILE_DURABILITY_QOS"
},
"durability_service":
{
"history_depth": 1,
"history_kind": "KEEP_LAST_HISTORY_QOS",
"max_instances": 30,
"max_samples": 3000,
"max_samples_per_instance": 100,
"service_cleanup_delay":
{
"nanoseconds": 0,
"seconds": 5
}
},
"group_data": "9d46781410ff",
"latency_budget":
{
"duration":
{
"nanoseconds": 50,
"seconds": 10
}
},
"lifespan":
{
"duration":
{
"nanoseconds": 0,
"seconds": 10000
}
},
"liveliness":
{
"announcement_period":
{
"nanoseconds": 0,
"seconds": 3
},
"lease_duration":
{
"nanoseconds": 0,
"seconds": 10
},
"kind": "AUTOMATIC_LIVELINESS_QOS"
},
"ownership":
{
"kind": "SHARED_OWNERSHIP_QOS"
},
"partition":
[
"partition_1",
"partition_2"
],
"presentation":
{
"access_scope": "INSTANCE_PRESENTATION_QOS",
"coherent_access": false,
"ordered_access": false
},
"reliability":
{
"kind": "RELIABLE_RELIABILITY_QOS",
"max_blocking_time":
{
"nanoseconds": 0,
"seconds": 3
}
},
"representation":
[
],
"time_based_filter":
{
"minimum_separation":
{
"seconds": 12,
"nanoseconds": 0
}
},
"topic_data": "5b33419a",
"type_consistency":
{
"force_type_validation": false,
"ignore_member_names": false,
"ignore_sequence_bounds": true,
"ignore_string_bounds": true,
"kind": "DISALLOW_TYPE_COERCION",
"prevent_type_widening": false
},
"user_data": "ff00"
},
"app_id": "SHAPES_DEMO"
}
1.7.8. DataWriter Info example¶
{
"id": 7,
"kind": "datawriter",
"name": "datawriter_name",
"alias": "datawriter_alias",
"alive": true,
"metatraffic": false,
"status": "OK",
"guid": "01.0f.22.cd.59.64.04.00.02.00.00.00|00.00.01.03",
"qos":
{
"data_sharing":
{
"domain_ids":
[
0
],
"kind": "AUTO",
"max_domains": 1,
"shm_directory": "/dev/shm"
},
"deadline":
{
"period":
{
"nanoseconds": 50,
"seconds": 10
}
},
"destination_order":
{
"kind": "BY_RECEPTION_TIMESTAMP_DESTINATIONORDER_QOS"
},
"disable_positive_acks":
{
"duration":
{
"nanoseconds": 100,
"seconds": 0
},
"enabled": true
},
"durability":
{
"kind": "VOLATILE_DURABILITY_QOS"
},
"durability_service":
{
"history_depth": 1,
"history_kind": "KEEP_LAST_HISTORY_QOS",
"max_instances": 30,
"max_samples": 3000,
"max_samples_per_instance": 100,
"service_cleanup_delay":
{
"nanoseconds": 0,
"seconds": 5
}
},
"group_data": "9d46781410ff",
"latency_budget":
{
"duration":
{
"nanoseconds": 50,
"seconds": 10
}
},
"lifespan":
{
"duration":
{
"nanoseconds": 0,
"seconds": 10000
}
},
"liveliness":
{
"announcement_period":
{
"nanoseconds": 0,
"seconds": 3
},
"lease_duration":
{
"nanoseconds": 0,
"seconds": 10
},
"kind": "AUTOMATIC_LIVELINESS_QOS"
},
"ownership":
{
"kind": "SHARED_OWNERSHIP_QOS"
},
"ownership_strength":
{
"value": 5
},
"partition":
[
"partition_1",
"partition_2"
],
"presentation":
{
"access_scope": "INSTANCE_PRESENTATION_QOS",
"coherent_access": false,
"ordered_access": false
},
"publish_mode":
{
"kind": "ASYNCHRONOUS_PUBLISH_MODE"
},
"reliability":
{
"kind": "RELIABLE_RELIABILITY_QOS",
"max_blocking_time":
{
"nanoseconds": 0,
"seconds": 3
}
},
"representation":
[
],
"time_based_filter":
{
"minimum_separation":
{
"seconds": 12,
"nanoseconds": 0
}
},
"topic_data": "5b33419a",
"user_data": "ff00"
},
"app_id": "SHAPES_DEMO"
}
1.7.9. Topic Info example¶
{
"id": 8,
"kind": "topic",
"name": "topic_name",
"alias": "topic_alias",
"alive": true,
"metatraffic": false,
"status": "OK",
"data_type": "example_data_type"
}