Data Availability

Use these QoS fields to configure how much data, which data, and when that data is available to an application.

Use these QoS fields to configure how much data, which data, and when that data is available to an application.

Data availability refers to configurations such as ownership and lifespan.

Basic Settings

dds::core::policy::Durability	kind
	<<basic>> <<spec>> The kind of durability.
dds::core::policy::Durability	writer_depth
	<<basic>> <<extension>> Indicates the number of samples per instance that a durable dds::pub::DataWriter will send to a late-joining dds::sub::DataReader.
dds::core::policy::Deadline	period
	<<basic>> <<spec>> Duration of the deadline period.
dds::core::policy::Ownership	kind
	<<basic>> <<spec>> The kind of ownership
dds::core::policy::OwnershipStrength	value
	<<basic>> <<spec>> The strength value used to arbitrate among multiple writers.
dds::core::policy::TimeBasedFilter	minimum_separation
	<<basic>> <<spec>> The minimum separation duration between subsequent samples.
dds::core::policy::History	kind
	<<basic>> <<spec>> Specifies the kind of history to be kept.
dds::core::policy::History	depth
	<<basic>> <<spec>> Specifies the number of samples per instance to be kept, when the kind is dds::core::policy::HistoryKind::KEEP_LAST
dds::core::policy::ResourceLimits	max_samples
	<<basic>> <<spec>> Represents the maximum samples the middleware can store for any one dds::pub::DataWriter (or dds::sub::DataReader).
dds::core::policy::ResourceLimits	max_instances
	<<basic>> <<spec>> Represents the maximum number of instances a dds::pub::DataWriter (or dds::sub::DataReader) can manage.
dds::core::policy::Lifespan	duration
	<<basic>> <<spec>> Maximum duration for the data's validity.
rti::core::MonitoringEventDistributionSettings	publication_period
	<<basic>> <<extension>> Period at which the event metric thread publishes the event metrics that have changed since the last time they were published.
rti::core::MonitoringPeriodicDistributionSettings	polling_period
	<<basic>> <<extension>> Period at which the periodic metric thread polls and publishes the periodic metrics.
rti::core::MonitoringLoggingDistributionSettings	publication_period
	<<basic>> <<extension>> Period at which the logging thread publishes log messages.

Advanced Settings

rti::core::policy::Availability	enable_required_subscriptions
	<<extension>> Enables support for required subscriptions in a dds::pub::DataWriter
rti::core::policy::Availability	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.
rti::core::policy::Availability	max_endpoint_availability_waiting_time
	<<extension>> Defines how much time to wait to discover DataWriters providing samples for the same data source (virtual GUID).
rti::core::policy::Availability	required_matched_endpoint_groups
	<<extension>> A sequence of endpoint groups.
dds::core::policy::Durability	direct_communication
	<<extension>> Indicates whether or not a TRANSIENT or PERSISTENT dds::sub::DataReader should receive samples directly from a TRANSIENT or PERSISTENT dds::pub::DataWriter
dds::core::policy::Durability	storage_settings
	<<extension>> Configures durable writer history and durable reader state.
dds::core::policy::DurabilityService	service_cleanup_delay
	<<spec>> Controls when the service is able to remove all information regarding a data instances.
dds::core::policy::DurabilityService	max_samples
	<<spec>> Part of resource limits QoS policy to apply when feeding a late joiner.
dds::core::policy::DurabilityService	max_instances
	<<spec>> Part of resource limits QoS policy to apply when feeding a late joiner.
dds::core::policy::DurabilityService	max_samples_per_instance
	<<spec>> Part of resource limits QoS policy to apply when feeding a late joiner.
dds::core::policy::Presentation	access_scope
	<<spec>> Determines the largest scope spanning the entities for which the order and coherency of changes can be preserved.
dds::core::policy::Presentation	coherent_access
	<<spec>> Specifies support for coherent access. Controls whether coherent access is supported within the scope access_scope.
dds::core::policy::Presentation	ordered_access
	<<spec>> Specifies support for ordered access to the samples received at the subscription end. Controls whether ordered access is supported within the scope access_scope.
dds::core::policy::Presentation	drop_incomplete_coherent_set
	<<extension>> Indicates whether or not a dds::sub::DataReader should drop samples from an incomplete coherent set (one for which not all the samples were received). Such samples are reported as lost in the SAMPLE_LOST Status.
dds::core::policy::LatencyBudget	duration
	<<spec>> Duration of the maximum acceptable delay.
dds::core::policy::ResourceLimits	max_samples_per_instance
	<<spec>> Represents the maximum number of samples of any one instance a dds::pub::DataWriter (or dds::sub::DataReader) can manage.
dds::core::policy::ReaderDataLifecycle	autopurge_nowriter_samples_delay
	<<spec>> Minimum duration for which the dds::sub::DataReader will maintain samples for an instance once its instance_state becomes dds::sub::status::InstanceState::not_alive_no_writers().
dds::core::policy::ReaderDataLifecycle	autopurge_disposed_samples_delay
	<<spec>> Minimum duration for which the dds::sub::DataReader will maintain samples for an instance once its instance_state becomes dds::sub::status::InstanceState::not_alive_disposed().
dds::core::policy::ReaderDataLifecycle	autopurge_disposed_instances_delay
	<<extension>> Minimum duration for which the dds::sub::DataReader will maintain information about a received instance once its instance_state becomes dds::sub::status::InstanceState::not_alive_disposed() and there are no samples for the instance in the DataReader queue.
dds::core::policy::ReaderDataLifecycle	autopurge_nowriter_instances_delay
	<<extension>> Minimum duration for which the dds::sub::DataReader will maintain information about a received instance once its instance_state becomes dds::sub::status::InstanceState::not_alive_no_writers() and there are no samples for the instance in the DataReader queue.
rti::core::policy::TransportMulticastMapping	value
	<<extension>> A sequence of multicast communication mappings.
rti::core::policy::TransportMulticast	kind
	<<extension>> A value that specifies a way to determine how to obtain the multicast address.
rti::core::policy::DataWriterProtocol	virtual_guid
	<<extension>> The virtual GUID (Global Unique Identifier).
rti::core::policy::DataWriterProtocol	push_on_write
	<<extension>> Whether to push sample out when write is called.
rti::core::policy::BuiltinTopicReaderResourceLimits	initial_outstanding_reads
	<<extension>> The initial number of outstanding reads that have not called finish yet on the same built-in topic dds::sub::DataReader.
rti::core::policy::BuiltinTopicReaderResourceLimits	max_outstanding_reads
	<<extension>> The maximum number of outstanding reads that have not called finish yet on the same built-in topic dds::sub::DataReader.
rti::core::policy::BuiltinTopicReaderResourceLimits	max_samples_per_read
	<<extension>> Maximum number of samples that can be read/taken on a same built-in topic dds::sub::DataReader.
rti::core::policy::Batch	source_timestamp_resolution
	<<extension>> Batch source timestamp resolution.
rti::core::ChannelSettings	priority
	<<extension>> Publication priority
rti::core::policy::MultiChannel	channels
	<<extension>> A sequence of rti::core::ChannelSettings used to configure the channels' properties. If the length of the sequence is zero, the QoS policy will be ignored.
rti::core::policy::MultiChannel	filter_name
	<<extension>> Name of the filter class used to describe the filter expressions of a MultiChannel DataWriter.