As part of one of my project implementation, I have to use Hyperledger Indy for providing digital identity to users. The estimated number of users on the platform is 20k. I am stuck on determining what must be the number of nodes required to run Hyperledger Indy for efficient use on production.
The number of nodes depends on the number of faulty nodes you want to permit. To support f faults in the system, you need 3f+1 total nodes. So if you are OK with only 2 nodes failing at any one time, you need f=2 or 7 total nodes. The practical limit has found to be f=8 or 25 total nodes. That balances a robust network with the speed of consensus.
How that relates to the number of users on the platform is a different question. It depends on (a) how many issuers, and (b) how much revocation is happening. If there is only one issuer and no revocation, there would only be 3 extra transactions beyond the genesis transactions. Not many...