<<extension>> The status of the reader's cache. More...

Inherits Status.

Public Attributes
long	sample_count_peak
	The highest number of samples in the reader's queue over the lifetime of the reader. More...

long	sample_count
	The number of samples in the reader's queue. More...

long	old_source_timestamp_dropped_sample_count
	The number of samples dropped as a result of receiving a sample older than the last one, using com.rti.dds.infrastructure.DestinationOrderQosPolicyKind.DestinationOrderQosPolicyKind.BY_SOURCE_TIMESTAMP_DESTINATIONORDER_QOS. More...

long	tolerance_source_timestamp_dropped_sample_count
	The number of samples dropped as a result of receiving a sample in the future, using com.rti.dds.infrastructure.DestinationOrderQosPolicyKind.DestinationOrderQosPolicyKind.BY_SOURCE_TIMESTAMP_DESTINATIONORDER_QOS. More...

long	ownership_dropped_sample_count
	The number of samples dropped as a result of receiving a sample from a DataWriter with a lower strength, using Exclusive Ownership. More...

long	content_filter_dropped_sample_count
	The number of user samples filtered by the DataReader due to Content-Filtered Topics. More...

long	time_based_filter_dropped_sample_count
	The number of user samples filtered by the DataReader due to com.rti.dds.infrastructure.TimeBasedFilterQosPolicy. More...

long	expired_dropped_sample_count
	The number of samples expired by the DataReader due to com.rti.dds.infrastructure.LifespanQosPolicy or the autopurge sample delays. More...

long	virtual_duplicate_dropped_sample_count
	The number of virtual duplicate samples dropped by the DataReader. A sample is a virtual duplicate if it has the same identity (Virtual Writer GUID and Virtual Sequence Number) as a previously received sample. More...

long	replaced_dropped_sample_count
	The number of samples replaced by the DataReader due to com.rti.dds.infrastructure.HistoryQosPolicyKind.HistoryQosPolicyKind.KEEP_LAST_HISTORY_QOS replacement. More...

long	writer_removed_batch_sample_dropped_sample_count
	The number of batch samples received by the DataReader that were marked as removed by the DataWriter. More...

long	total_samples_dropped_by_instance_replacement
	The number of samples with sample state com.rti.dds.subscription.SampleStateKind.SampleStateKind.NOT_READ_SAMPLE_STATE that were dropped when removing an instance due to instance replacement. See com.rti.dds.infrastructure.DataReaderResourceLimitsQosPolicy.instance_replacement for more details about when instances are replaced. More...

long	alive_instance_count
	The number of instances in the DataReader's queue with an instance state equal to com.rti.dds.subscription.InstanceStateKind.ALIVE_INSTANCE_STATE. More...

long	alive_instance_count_peak
	The highest value of com.rti.dds.subscription.DataReaderCacheStatus.alive_instance_count over the lifetime of the DataReader. More...

long	no_writers_instance_count
	The number of instances in the DataReader's queue with an instance state equal to com.rti.dds.subscription.InstanceStateKind.NOT_ALIVE_NO_WRITERS_INSTANCE_STATE. More...

long	no_writers_instance_count_peak
	The highest value of com.rti.dds.subscription.DataReaderCacheStatus.no_writers_instance_count over the lifetime of the DataReader. More...

long	disposed_instance_count
	The number of instances in the DataReader's queue with an instance state equal to com.rti.dds.subscription.InstanceStateKind.NOT_ALIVE_DISPOSED_INSTANCE_STATE. More...

long	disposed_instance_count_peak
	The highest value of com.rti.dds.subscription.DataReaderCacheStatus.disposed_instance_count over the lifetime of the DataReader. More...

long	detached_instance_count
	The number of minimal instance states currently being maintained in the DataReader's queue. More...

long	detached_instance_count_peak
	The highest value of com.rti.dds.subscription.DataReaderCacheStatus.detached_instance_count over the lifetime of the DataReader. More...

long	compressed_sample_count
	The number of received compressed samples by a DataWriter. More...

Detailed Description

<<extension>> The status of the reader's cache.

Entity:: com.rti.dds.subscription.DataReader

Member Data Documentation

◆ sample_count_peak

long sample_count_peak

The highest number of samples in the reader's queue over the lifetime of the reader.

◆ sample_count

long sample_count

The number of samples in the reader's queue.

includes samples that may not yet be available to be read or taken by the user, due to samples being received out of order or PRESENTATION

◆ old_source_timestamp_dropped_sample_count

long old_source_timestamp_dropped_sample_count

The number of samples dropped as a result of receiving a sample older than the last one, using com.rti.dds.infrastructure.DestinationOrderQosPolicyKind.DestinationOrderQosPolicyKind.BY_SOURCE_TIMESTAMP_DESTINATIONORDER_QOS.

When the DataReader is using com.rti.dds.infrastructure.DestinationOrderQosPolicyKind.DestinationOrderQosPolicyKind.BY_SOURCE_TIMESTAMP_DESTINATIONORDER_QOS:

If the DataReader receives a sample for an instance with a source timestamp that is older than the last source timestamp received for the instance, the sample is dropped.

If the DataReader receives a sample for an instance with a source timestamp that is equal to the last source timestamp received for the instance and the writer has a higher virtual GUID, the sample is dropped.

◆ tolerance_source_timestamp_dropped_sample_count

long tolerance_source_timestamp_dropped_sample_count

The number of samples dropped as a result of receiving a sample in the future, using com.rti.dds.infrastructure.DestinationOrderQosPolicyKind.DestinationOrderQosPolicyKind.BY_SOURCE_TIMESTAMP_DESTINATIONORDER_QOS.

When the DataReader is using com.rti.dds.infrastructure.DestinationOrderQosPolicyKind.DestinationOrderQosPolicyKind.BY_SOURCE_TIMESTAMP_DESTINATIONORDER_QOS: the DataReader will accept a sample only if the source timestamp is no farther in the future from the reception timestamp than the source_timestamp_tolerance. Otherwise, the sample is dropped.

◆ ownership_dropped_sample_count

long ownership_dropped_sample_count

The number of samples dropped as a result of receiving a sample from a DataWriter with a lower strength, using Exclusive Ownership.

When using Exclusive Ownership, the DataReader receives data from multiple DataWriters. Each instance can only be owned by one DataWriter.

If other DataWriters write samples on this instance, the samples will be dropped.

◆ content_filter_dropped_sample_count

long content_filter_dropped_sample_count

The number of user samples filtered by the DataReader due to Content-Filtered Topics.

When using a content filter on the DataReader side, if the sample received by the DataReader does not pass the filter, it will be dropped.

◆ time_based_filter_dropped_sample_count

long time_based_filter_dropped_sample_count

The number of user samples filtered by the DataReader due to com.rti.dds.infrastructure.TimeBasedFilterQosPolicy.

When using TIME_BASED_FILTER on the DataReader side, if the sample received by the DataReader does not pass the minimum_separation filter, it will be dropped.

◆ expired_dropped_sample_count

long expired_dropped_sample_count

The number of samples expired by the DataReader due to com.rti.dds.infrastructure.LifespanQosPolicy or the autopurge sample delays.

com.rti.dds.infrastructure.LifespanQosPolicy
When a sample expires due to com.rti.dds.infrastructure.LifespanQosPolicy, the data is removed from the DataReader caches. This sample will be considered dropped if its com.rti.dds.subscription.SampleStateKind was com.rti.dds.subscription.SampleStateKind.SampleStateKind.NOT_READ_SAMPLE_STATE.
com.rti.dds.infrastructure.ReaderDataLifecycleQosPolicy.autopurge_nowriter_samples_delay
When a sample expires due to com.rti.dds.infrastructure.ReaderDataLifecycleQosPolicy.autopurge_nowriter_samples_delay, this sample will be considered dropped if its com.rti.dds.subscription.SampleStateKind was com.rti.dds.subscription.SampleStateKind.SampleStateKind.NOT_READ_SAMPLE_STATE.
com.rti.dds.infrastructure.ReaderDataLifecycleQosPolicy.autopurge_disposed_samples_delay
When a sample expires due to com.rti.dds.infrastructure.ReaderDataLifecycleQosPolicy.autopurge_disposed_samples_delay, this sample will be considered dropped if its com.rti.dds.subscription.SampleStateKind was com.rti.dds.subscription.SampleStateKind.SampleStateKind.NOT_READ_SAMPLE_STATE.

◆ virtual_duplicate_dropped_sample_count

long virtual_duplicate_dropped_sample_count

The number of virtual duplicate samples dropped by the DataReader. A sample is a virtual duplicate if it has the same identity (Virtual Writer GUID and Virtual Sequence Number) as a previously received sample.

When two DataWriters with the same logical data source publish a sample with the same sequence_number, one sample will be dropped and the other will be received by the DataReader.

This can happen when multiple writers are writing on behalf of the same original DataWriter: for example, in systems with redundant Routing Services or when a DataReader is receiving samples both directly from the original DataWriter and from an instance of Persistence Service.

◆ replaced_dropped_sample_count

long replaced_dropped_sample_count

The number of samples replaced by the DataReader due to com.rti.dds.infrastructure.HistoryQosPolicyKind.HistoryQosPolicyKind.KEEP_LAST_HISTORY_QOS replacement.

When the number of samples for an instance in the queue reaches the com.rti.dds.infrastructure.HistoryQosPolicy.depth value, a new sample for the instance will replace the oldest sample for the instance in the queue.

The new sample will be accepted and the old sample will be dropped.

This counter will only be updated if the replaced sample's com.rti.dds.subscription.SampleStateKind was com.rti.dds.subscription.SampleStateKind.SampleStateKind.NOT_READ_SAMPLE_STATE.

◆ writer_removed_batch_sample_dropped_sample_count

long writer_removed_batch_sample_dropped_sample_count

The number of batch samples received by the DataReader that were marked as removed by the DataWriter.

When the DataReader receives a batch, the batch can contain samples marked as removed by the DataWriter. Examples of removed samples in a batch could be because of sample replacement due to com.rti.dds.infrastructure.HistoryQosPolicyKind.HistoryQosPolicyKind.KEEP_LAST_HISTORY_QOS com.rti.dds.infrastructure.HistoryQosPolicy QoS on the DataWriter or because the duration in com.rti.dds.infrastructure.LifespanQosPolicy was reached. By default, any sample marked as removed from a batch is dropped (unless you set the dds.data_reader.accept_writer_removed_batch_samples property in the com.rti.dds.infrastructure.PropertyQosPolicy to true). Note: Historical data with removed batch samples written before the DataReader joined the DDS domain will also be included in the count.

◆ total_samples_dropped_by_instance_replacement

long total_samples_dropped_by_instance_replacement

The number of samples with sample state com.rti.dds.subscription.SampleStateKind.SampleStateKind.NOT_READ_SAMPLE_STATE that were dropped when removing an instance due to instance replacement. See com.rti.dds.infrastructure.DataReaderResourceLimitsQosPolicy.instance_replacement for more details about when instances are replaced.