A rollback happens when a node discovers that the chain it has been following has been overtaken by a longer chain produced by a different fork. The conflicting tip blocks are reverted, and the node switches to the new chain.
Short rollbacks of one or two blocks are normal during high-traffic periods; deeper rollbacks are rare on Cardano because the Ouroboros chain-selection rule converges quickly. Wallets, explorers, and dApp indexers must handle rollbacks gracefully so they never show users transactions that have since been reverted off the chain.
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- BlockA unit of data containing a batch of transactions that is added to the blockchain.View term
- OuroborosThe family of proof-of-stake consensus protocols that power Cardano, designed with formal security proofs against the known attack catalogue against PoS chains.View term
- SlotEach slot represents an opportunity for a block to be produced by an elected slot leader.View term