A sequencer bug was the reason for two outages on Coinbase’s Layer 2 community Base final week, in line with a postmortem.
base engineering staff stated A autopsy on Saturday recognized a bug within the sequencer’s block development logic that allowed “stale journal state” to persist after a failed transaction validation.
“An invalid transaction was obtained by the block builder and failed throughout execution as anticipated, however the journal state containing accessed accounts and storage slots was inadvertently not cleared,” the staff stated.
base layer 2 community Run a single sequencer. Which means one bug can carry all the pieces down. It’s a centralized blockchain element that orders transactions and has been the reason for outages for different layer 2 chains equivalent to Arbitrum, OP Mainnet, and zkSync Period.
Two outages occurred on the Base mainnet on Thursday and Friday, with the primary incident lasting 116 minutes and the second incident lasting 20 minutes.
Sequencer and validator nodes have been unable to advance past the invalid block till the brand new layer 2 block was fully stopped and the sequence was restored.
The staff mounted the failure by patching the sequencer in order that the journal state is up to date correctly throughout execution.
Nevertheless, they stated mitigation took longer than anticipated “because of infrastructure circumstances unrelated to the unique bug.”
Additionally, after a system reset, a “race situation” occurred and the sequencer could not sustain, inflicting a second outage.
Associated: Coinbase’s Base resumes block manufacturing after 2-hour outage
Sooner or later, the Base engineering staff plans to enhance the “fuzz check” of the protocol. This contains bombarding the system with giant quantities of random, malformed, or surprising enter to search out bugs, and constructing in “swish restoration” in order that validator nodes don’t must be manually restarted within the occasion of future incidents.
This isn’t the primary time Base has been out of service.
This isn’t the primary sequencer-related outage for Base, which stopped producing blocks for 17 minutes in September 2024 and for about half-hour in August 2025.
Base is the second largest Layer 2 community by complete quantity secured, at just below $11 billion. In keeping with To L2 beat.
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