Polygon blockchain network went down for 11-hours

Polygon, the millennial Layer-2 solution on Ethereum blockchain went down for 11 hours. According to reports, the network was down from 05:50 PM UTC on Thursday until about 04:00 AM UTC on Friday. However, users on the blockchain need to worry as their funds are all safe. According to the team, they are working on identifying the definitive cause. Moreover, they explained that it seems such issues have originated from an earlier upgrade consisting of a minor parameterizing fix to the Ether to Polygon Proof-of-Stake state sync/bridging module.

What caused Polygon down time?

On Thursday, the brains behind Polygon notified the users across the world of an upcoming potential downtime for the network. According to the team, the downtime would be witnessed because of a planned network upgrade, the Heimdall node.

Notably, the Heimdall node implementation is used by one of the two layers of the network’s Proof-of-Stake chain. Moreover, the Polygon’s team confirmed the downtime at 5:50 PM UTC on Thursday, and provided further clarifications.

The team highlighted that while they were working on to identify the definitive cause, it seems that they have originated from an earlier upgrade consisting of a minor parameterizing fix. Furthermore, they have unveiled that there may have been a bug in the upgrade. Indeed, the bug would have an effect on the consensus and lead the network to different Heimdall validators being on different versions of the blockchain.

Notably, the bug would have prevented the blockchain from reaching 2/3 consensus. According to Polygon’s team, if they use Tenderming consensus, the situation will cause the Heimdall chain to halt.

Furthermore, they reaffirmed that Heimdall does not handle user transactions. The node is used by validators-related bridging and transactions. The Borchain, that relies on Heimdall for block proposer committee selection, also halted.

How did the team restore the blockchain?

The team behind Polygon released a hotfix, which restored all the operations on the blockchain. However, it is notable that the Bridge itself will not be active until the team entirely resolves the issue.

Following the restoration, the team underscored that they appreciate the community support during such a time. They further updated that they have deployed a temporary hotfix to unblock the Bor chain and resume producing blocks on the network. Still, the solution wasn’t permanent, so the team is working on implementing a longer-term upgrade to fix the Heimdall issue.

As the final solution is released, the network bridge will not get activated till then.