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Known issues & limitations

Please be aware of the following known issues and limitations before running hydra-node on the Cardano --mainnet; as an incredibly technical project, Hydra in its current form requires an elevated level of understanding of the underlying infrastructure. Without the expertise required to operate a hydra-node, users may put their funds at risk if they are unfamiliar with the implementation and usage process.

Head protocol limits​

As transaction sizes and execution budgets are limited on Cardano:

  • The protocol can only handle a maximum number of participants in a Head (see cost of collectcom transaction). Upon startup, the hydra-node will inform you of the current configured maximum when trying to configure too many peers.

It's currently possible to be denied access to funds by other protocol participants at various stages in a Hydra Head because of the complexity or size of the UTxO being committed or created while the Head is open:

  • The head cannot be finalized if holding more than ~80 assets (see cost of fanout transaction for latest numbers), although it can be closed
  • Tokens minted and not burnt in an open head will prevent it from being finalized
  • If one or more participants commit UTxO too large to be processed together in a CollectCom or Abort transaction, the Head will be stuck in the initialising stage

There are couple of items in the roadmap around reducing the risk of locking up funds in a Hydra Head:

Training wheels​

  • There is a hard-coded limit on mainnet network where you can only commit up to 100 ADA into the Hydra head. This is only a safety precaution and is going to be increased as we gain more experience in running Hydra heads on the mainnet.

Known bugs​

Refer also to the project repository issue tracker for known issues with the code. Should you discover any security relevant problems, please follow our security policy.