Use these QoS fields to configure how much and how long data remains retrievable in the system.


DDS_AvailabilityQosPolicy	enable_required_subscriptions
	<<extension>> Enables support for required subscriptions in a DDS_DataWriter

DDS_AvailabilityQosPolicy	max_data_availability_waiting_time
	<<extension>> Defines how much time to wait before delivering a sample to the application without having received some of the previous samples.

DDS_AvailabilityQosPolicy	max_endpoint_availability_waiting_time
	<<extension>> Defines how much time to wait to discover DataWriters providing samples for the same data source (virtual GUID).

DDS_AvailabilityQosPolicy	required_matched_endpoint_groups
	<<extension>> A sequence of endpoint groups.

DDS_DurabilityQosPolicy	kind
	<<basic>> <<spec>> The kind of durability.

DDS_DurabilityQosPolicy	direct_communication
	<<extension>> Indicates whether or not a TRANSIENT or PERSISTENT DDS_DataReader should receive samples directly from a TRANSIENT or PERSISTENT DDS_DataWriter

DDS_DurabilityQosPolicy	writer_depth
	<<basic>> <<extension>> Indicates the number of samples per instance that a durable DDS_DataWriter will send to a late-joining DDS_DataReader.

DDS_DurabilityQosPolicy	storage_settings
	<<extension>> Configures durable writer history and durable reader state.

DDS_PersistentStorageSettings	enable
	<<extension>> Enables durable writer history in a DDS_DataWriter and durable reader state in a DDS_DataReader.

DDS_PersistentStorageSettings	file_name
	<<extension>> The file name where the durable writer history or durable reader state will be stored.

DDS_PersistentStorageSettings	trace_file_name
	<<extension>> The file name where to store the SQL statements executed when loading and storing the durable writer history or durable reader state.

DDS_PersistentStorageSettings	journal_kind
	<<extension>> Sets the journal mode of the persistent storage.

DDS_PersistentStorageSettings	synchronization_kind
	<<extension>> Sets the level of synchronization with the physical disk.

DDS_PersistentStorageSettings	vacuum
	<<extension>> Sets the auto-vacuum status of the storage.

DDS_PersistentStorageSettings	restore
	<<extension>> Indicates if the persisted writer history or reader state must be restored.

DDS_PersistentStorageSettings	writer_instance_cache_allocation
	<<extension>> Configures the resource limits associated with the instance durable writer history cache.

DDS_PersistentStorageSettings	writer_sample_cache_allocation
	<<extension>> Configures the resource limits associated with the sample durable writer history cache.

DDS_PersistentStorageSettings	writer_memory_state
	<<extension>> Determines how much state will be kept in memory by the durable writer history in order to avoid accessing the persistent storage in disk.

DDS_PersistentStorageSettings	reader_checkpoint_frequency
	<<extension>> Controls how often the reader state is stored into the database.

DDS_DurabilityServiceQosPolicy	service_cleanup_delay
	<<spec>> Controls when the service is able to remove all information regarding a data instances.

DDS_DurabilityServiceQosPolicy	history_kind
	<<spec>> The kind of history to apply in recouping durable data.

DDS_DurabilityServiceQosPolicy	history_depth
	<<spec>> Setting to use for the DDS_DurabilityQosPolicy::writer_depth when recouping durable data.

DDS_DurabilityServiceQosPolicy	max_samples
	<<spec>> Part of resource limits QoS policy to apply when feeding a late joiner.

DDS_DurabilityServiceQosPolicy	max_instances
	<<spec>> Part of resource limits QoS policy to apply when feeding a late joiner.

DDS_DurabilityServiceQosPolicy	max_samples_per_instance
	<<spec>> Part of resource limits QoS policy to apply when feeding a late joiner.

DDS_ResourceLimitsQosPolicy	max_samples
	<<basic>> <<spec>> Represents the maximum samples the middleware can store for any one DDS_DataWriter (or DDS_DataReader).

DDS_ResourceLimitsQosPolicy	max_instances
	<<basic>> <<spec>> Represents the maximum number of instances a DDS_DataWriter (or DDS_DataReader) can manage.

DDS_ResourceLimitsQosPolicy	max_samples_per_instance
	<<spec>> Represents the maximum number of samples of any one instance a DDS_DataWriter (or DDS_DataReader) can manage.

DDS_LifespanQosPolicy	duration
	<<basic>> <<spec>> Maximum duration for the data's validity.

DDS_DataWriterProtocolQosPolicy	propagate_app_ack_with_no_response
	<<extension>> Controls whether or not a DDS_DataWriter receives DDS_DataWriterListener::on_application_acknowledgment notifications with an empty or invalid response.

DDS_RtpsReliableWriterProtocol_t	disable_positive_acks_enable_adaptive_sample_keep_duration
	[DEPRECATED] <<extension>> Enables dynamic adjustment of sample keep duration in response to congestion.

DDS_RtpsReliableWriterProtocol_t	disable_positive_acks_min_sample_keep_duration
	<<extension>> The minimum duration a sample is queued for ACK-disabled readers.

DDS_RtpsReliableWriterProtocol_t	disable_positive_acks_max_sample_keep_duration
	<<extension>> The maximum duration a sample is queued for ACK-disabled readers.

DDS_RtpsReliableWriterProtocol_t	disable_positive_acks_decrease_sample_keep_duration_factor
	[DEPRECATED] <<extension>> Controls rate of contraction of dynamic sample keep duration.

DDS_RtpsReliableWriterProtocol_t	disable_positive_acks_increase_sample_keep_duration_factor
	[DEPRECATED] <<extension>> Controls rate of growth of dynamic sample keep duration.

DDS_BuiltinTopicReaderResourceLimits_t	initial_samples
	<<extension>> Initial number of samples.

DDS_BuiltinTopicReaderResourceLimits_t	max_samples
	<<extension>> Maximum number of samples.

DDS_EntityNameQosPolicy	role_name
	<<extension>> The entity role name.