6.1. Known Issues with Discovery

6.1.1. SPDP2

The following known issues apply to the Simple Participant Discovery Protocol 2.0, which is an alternative version of the Simple Participant Discovery Protocol, designed for decreased bandwidth usage and improved reliability. See Simple Participant Discovery 2.0, in the RTI Connext Core Libraries User’s Manual for more information.

6.1.1.1. Features under future consideration for SPDP2

Note

RTI does not guarantee the following features for any release or timeline. If any of these enhancements is of interest to you, please provide that feedback through your account team.

The following features, which are not currently supported, are being considered for SPDP2 in future releases:

  • Use of SPDP2 with custom security plugins (for example, those implemented with the Security Plugins SDK). Only the Builtin Security Plugins and the Lightweight Builtin Security Plugins are supported in combination with SPDP2.

  • SPDP and SPDP2 compatibility mode. The compatibility mode will allow some DomainParticipants to simultaneously communicate with DomainParticipants that are using SPDP and SPDP2. DomainParticipants that are using the compatibility mode will be able to communicate with DomainParticipants that are using SPDP and other DomainParticipants that are using SPDP2. For now, you can use RTI Routing Service to achieve this communication.

  • Improved configuration update behavior. Currently, when a DomainParticipant changes its configuration (partition, locators, etc.), it sends out:

    • If SPDP is enabled: a single Data(p) to all peers (matched or potential).

    • If SPDP2 is enabled: a single reliable message to matched peers, a single bootstrap message to unmatched initial peers. RTI will add an option to send multiple Data(p)s/bootstrap messages, since these messages are sent best-effort and can get lost, delaying configuration change updates in remote participants until the next periodic message.

[RTI Issue IDs CORE-12929, CORE-13884, and CORE-12930]

6.1.1.2. Participants using SPDP2 and allow_unauthenticated_participants fail to communicate if only one participant fails authentication

DomainParticipants using SPDP2 with allow_unauthenticated_participants set to TRUE fail to communicate if both participants are using security and only one participant fails authentication.

[RTI Issue ID SEC-2348]

6.1.2. TypeObject v2 not serialized correctly on big endian platforms

On big endian platforms, the TypeLookupService reply DataWriter serializes the requested TypeObject v2 objects in big endian. The OMG ‘Extensible and Dynamic Topic Types for DDS’ specification, version 1.4 mandates that TypeObject v2 objects must always be serialized in little endian. Connext applications will successfully deserialize these samples, but it is not guaranteed that other DDS vendors will.

[RTI Issue ID CORE-16510]