Consensus Hiccup Hits Polygon’s Heimdall V2, Fix Implemented

Polygon’s network experienced a short disruption on Wednesday after a technical issue affected Heimdall V2, a core part of its infrastructure. The interruption, which lasted around an hour, was caused by a bug in the system’s consensus mechanism. The development team has since restored operations and addressed the fault.

Polygon’s Heimdall V2 Briefly Disrupted

Heimdall V2 plays a major role in Polygon’s Proof-of-Stake (PoS) architecture. It oversees validator coordination, block management, and data alignment between Polygon and Ethereum. Around 9:30 AM UTC, this component briefly stopped functioning due to an issue related to validator exit activity.

Despite Heimdall’s temporary failure, the block production layer, known as Bor, continued operating. As a result, regular transactions remained active on the Polygon network throughout the incident.

RPC Sync Issues Follow Recovery, Most Services Restored

After Heimdall was brought back online, Polygon noticed that some RPC services had trouble staying in sync with Bor nodes. These services help connect users and applications to the network. To fix the issue, the team began working directly with each RPC provider to bring everything back in line. A spokesperson told Cointelegraph:

Following Heimdall’s recovery, we observed sync inconsistencies emerging across several RPC providers’ Bor nodes. We are now actively collaborating with all RPC partners to accelerate resolution and restore full availability. One provider is already back online, with slightly delayed sync.

In an update shared on X, the Polygon Foundation noted that nearly all RPC providers were back online, with user-facing tools gradually returning as well. It also mentioned that some services might still be performing below normal levels and confirmed another update would be issued once full restoration is achieved.

Heimdall V2 Upgrade Brings Major Technical Advancements

The consensus-related issue appeared not long after the launch of the Heimdall V2 upgrade, which was rolled out on July 10. That update introduced several key improvements to the Polygon PoS system, including the following:

• Heimdall V2 cuts finality time to 5 seconds, enabling real-time stablecoin transfers for users and apps.
• The upgrade introduced CometBFT and Cosmos-SDK v0.50 to boost performance and system reliability.
• The development makes Polygon suitable for regulated finance and custodial systems handling real-world assets.
• CEO Sandeep Nailwal called it Polygon’s most complex upgrade since the network launched in 2020.

Polygon’s Past Challenges and Wider Industry Context

Meanwhile, in the past, Heimdall experienced a technical setback. In March 2022, its earlier version, Heimdall V1, had a network disruption. At the time, the team believed a bug in the upgrade may have led validators to operate on mismatched versions of the chain. 

This mismatch prevented the network from reaching the level of agreement needed to function properly, which caused the system to pause until it was corrected.

Polygon remains one of the most widely used Ethereum scaling networks, with over $1.1 billion in total value locked across its ecosystem. Despite the recent glitch, key network functions remained uninterrupted, and resolution efforts were handled swiftly.

Other blockchain networks have also faced service issues recently. For instance, on July 29, Hyperliquid saw an API slowdown due to a surge in user traffic. The brief issue disrupted order processing but wasn’t caused by any external attack. The team has since taken steps to improve stability during high-demand periods.