# 17.1.1.3.11. DurabilityServiceQosPolicy¶

class eprosima::fastdds::dds::DurabilityServiceQosPolicy : public eprosima::fastdds::dds::Parameter_t, public eprosima::fastdds::dds::QosPolicy

Specifies the configuration of the durability service. That is, the service that implements the DurabilityQosPolicy kind of TRANSIENT and PERSISTENT.

Warning

This QosPolicy can be defined and is transmitted to the rest of the network but is not implemented in this version.

Note

Immutable Qos Policy

Public Functions

DurabilityServiceQosPolicy()

Constructor.

~DurabilityServiceQosPolicy() = default

Destructor.

void clear() override

Clears the QosPolicy object.

Public Members

fastrtps::Duration_t service_cleanup_delay

Control when the service is able to remove all information regarding a data-instance.

By default, c_TimeZero.

HistoryQosPolicyKind history_kind

Controls the HistoryQosPolicy of the fictitious DataReader that stores the data within the durability service.

By default, KEEP_LAST_HISTORY_QOS.

int32_t history_depth

Number of most recent values that should be maintained on the History. It only have effect if the history_kind is KEEP_LAST_HISTORY_QOS.

By default, 1.

int32_t max_samples

Control the ResourceLimitsQos of the implied DataReader that stores the data within the durability service. Specifies the maximum number of data-samples the DataWriter (or DataReader) can manage across all the instances associated with it. Represents the maximum samples the middleware can store for any one DataWriter (or DataReader). It is inconsistent for this value to be less than max_samples_per_instance.

By default, LENGTH_UNLIMITED.

int32_t max_instances

Control the ResourceLimitsQos of the implied DataReader that stores the data within the durability service. Represents the maximum number of instances DataWriter (or DataReader) can manage.

By default, LENGTH_UNLIMITED.

int32_t max_samples_per_instance

Control the ResourceLimitsQos of the implied DataReader that stores the data within the durability service. Represents the maximum number of samples of any one instance a DataWriter(or DataReader) can manage. It is inconsistent for this value to be greater than max_samples.

By default, LENGTH_UNLIMITED.