Maximum number of DDS Topics that may be created in a single DDS Domain

Question

Is there a limit to the number of Topics that may be created for a particular Domain in DDS? Is this implementation-dependent?

What is the maximum for RTI Connext DDS 5.0.0? I don't see it specified in the documentation.

Answer 1

With Connext, the limiting factor is not so much the number of Topics, but more the number of DataReaders and DataWriters created in a particular Domain. Of course, each DataReader and DataWriter is associated with exactly one Topic, so indirectly there is a dependency on the number of Topics.

With regard to the maximum number of DataReader and DataWriters in a Domain (often collectively indicated by Endpoints), the practical limitations depend on the resources in your system. Memory consumption due to administration of the topology of your DDS system will increase with the number of Endpoints. There is no hard or hard-coded limit on the number of Endpoints though.

If you have any particular scale in mind, I could indicate where you are in comparison to other users of the product.

This answer is indeed implementation dependent. My remarks apply to RTI Connext DDS and are not necessarily true for other DDS implementations.

Answer 2

The 'magic' limit of 240 you recalled was most likely either the maximum number of DomainParticipants that can run on a single computer on the same domain ID, which is 120. Or else it is the maximum number of DDS domain IDs, which is 233. See http://community.rti.com/kb/what-maximum-number-participants-domain

As Reinier mentioned there are no intrinsic limits to the number of endpoints.

Gerardo