The error message flags that it is trying to use the db.t3.small class. When I go directly to the RDS service, I see only db.t3.medium and db.t3.large classes are available.
I’m sorry, but we may not be able to provide a lot of guidance here as we (OSC) did not develop this and have never ran it (at least to my knowledge). That said there’s another similar topic - Error in deploying Open OnDemand on AWS
@cpollard0 provides some information on that topic, though I don’t know if it was ever resolved.
Please use this GitHub - aws-samples/open-on-demand-on-aws to deploy OODv3 in your AWS environment. That workshop is out-dated. Please reach out to me directly ( you can message me on this platform) if you need further assistance.
Jianjun: I’ve updated the GitHub - aws-samples/open-on-demand-on-aws redirect to point to this github repo instead of the workshop. That should steer most people towards it.