Introduction

The Property QoS Policy stores name/value (string) pairs that can be used to configure certain parameters of Connext DDS that are not exposed through formal QoS policies.

The Property QoS Policy stores name/value pairs for an entity. Both the name and value are strings. You can find more information about the RTI Connext DDS Property QoS in the “PROPERTY QosPolicy (DDS Extension)” section of the Core Libraries User’s Manual.

This knowledge base article also explains how to use a property. A property can be set programmatically as part of the QoS of the entity or by the XML QoS configuration. For example, here is the XML QoS configuration for the message_size_max property:

<domain_participant_qos>
    <property>
        <value>
            <element>
                <name>dds.transport.UDPv4.builtin.parent.message_size_max</name>
                <value>65507</value>
            </element>
        </value>
    </property>
</domain_participant_qos>

All the properties that Connext DDS provides (which begin with dds., com.rti., or rti.) are validated when the entity or the plugin is created. This validation is done to avoid using an unknown or incorrect property name (for example, due to a typo). Without this validation, Connext DDS ignores the unknown property name, and you might not know why the property’s configuration isn’t being applied. Find more information in the “Property Validation” section of the Core Libraries User’s Manual.

The goal of this Property Reference Guide is to gather all Connext DDS properties in one place and provide the main characteristics of each. This reference guide is organized into three main indexes:

  • The whole list of properties organized by hierarchy. For example, if you want to learn more about the property dds.transport.UDPv4.builtin.parent.allow_interfaces_list, go to the List of Properties: click on dds.transport, then UDPv4.builtin, then parent, to find full information on the property.

  • The whole list of properties organized by entities. For example, you will see all the properties that can be set for the DataWriter.

  • The whole list of properties organized by features. For example, you can find all properties related to “instances,” “durability,” or “reliability”; if you are working on discovery configuration, you can find all properties related to “discovery.”

For each property, you will find the following information:

  • An icon to copy the property name for accurate insertion into your XML file.

  • A link to the full documentation of the property.

  • The entity in which the property can be set and the entity to which it can apply. Usually, these will be the same, but not always. For example, some properties can be set for the DomainParticipant, DataWriter, and DataReader, but apply only to the DataWriter and DataReader.

  • A brief description of the property, as well as its type, default value, value range, and so on.

  • The related features for the property (is it related to “reliability” or “instances,” etc.).

  • If the property has been promoted to a QoS, the name of the promoted QoS.

Here is an example entry for dds.transport.UDPv4.builtin.parent.allow_interfaces_list:

_images/property_example.png