Step 2: Oracle consensus
Once all validators fetch all necessary data from registered URLs and stored in cache memory, all validators communicate with each other to form the oracle consensus using Practical Byzantine Fault Tolerance consensus protocol. The consensus is considered agreement if more than ⅔ of the validators agree on the fetched data. The consensus aggregates data and creates aggregated off-chain data.
The aggregation method can vary for different kinds of data. For example, Aggregation for ETH/USD price data can be the average of all individual ETH price data fetched by all validators. The data can be finalized if there are more than ⅔ of the validators participating in the aggregation. Less than ⅔ of the validators would result in consensus failure, thus the transaction gets rejected.
Note that the aggregated off-chain data is the real time off-chain data that will be feed in the Oracle Data Layer of all validators.