How many clients do hydra support?

[whs-dot-hk]

The demo show 3 Alice, Bob and Carol. What is the maximum number of connections hydra support?

[ch1bo]

One needs to distinguish between client connections and connections between hydra-nodes.

• Client connections are used to attach user interfaces or other applications to the hydra-node. We did not test how many parallel are possible as they should be somewhat local & authenticated.
• Network connections are used to actually communicated the Hydra off-chain protocol between hydra-nodes. Currently a connection is established between all participants (Alice, Bob & Carol in the example). The limit here is rarely the number of possible connections, but rather protocol complexity. That is, the number of messages which need to be exchanged between participants to submit transactions & sign snapshots (off-chain head states). The limit here depends in how fast the Hydra Head needs to be. Confirmation times become longer depending on the number of participants. While you get sub-second confirmation times for transactions with 1-10 participants, they become much longer with 10+ parties.

The number of participants is not only impacting the number of network connections required, but also the size & cost of layer 1 transactions needed to open a Hydra Head. Currently that is the limit and allows for only 3-4 participant per Head. We expect that to become less of a factor when we get the plutus improvements from the Vasil hardfork.