Submitted by Ch_301, also found by oakcobalt and bin2chen
Chainlink recommends that all Optimistic L2 oracles consult the Sequencer Uptime Feed to ensure that the sequencer is live before trusting the data returned by the oracle.
If the Arbitrum Sequencer goes down, oracle data will not be kept up to date, and thus could become stale. However, users are able to continue to interact with the protocol directly through the L1 optimistic rollup contract. You can review Chainlink docs on L2 Sequencer Uptime Feeds for more details on this.
This protocol uses getPriceOracle() everywhere and it sub call to PriceOracle.sol#latestRoundData(). As a result, users may be able to use the protocol while Oracle feeds are stale. This could cause many problems, for example:
If the Arbitrum sequencer goes down, the protocol will allow users to continue to operate at the previous (stale) prices. This will break all the core functionality in the protocol.
Solodit
It is recommended to follow the code example of Chainlink here or just add this check:
Oracle
thorseldon (BendDAO) acknowledged and commented:
