SDF's validator nodes went offline for 10 hours on April 10, 2021, but the Stellar network continued operating normally with other validators. The issue was traced to a single operation in one ledger, fixed via Protocol 16 upgrade, demonstrating the network's decentralized resilience.
On April 10, 2021, the Stellar Development Foundation's validator nodes and public Horizon API temporarily halted, unable to process transactions for approximately 10 hours. However, the broader Stellar network remained operational because sufficient validator redundancy existed among other ecosystem participants. SDF engineers identified the root cause as a single problematic operation within a specific ledger, developed a patch by Wednesday, and released Stellar Core v16.0.0 on Thursday. Network validators voted to upgrade to Protocol 16 on Saturday, enabling affected nodes to recover and restore service. The incident demonstrated that the Stellar network functions as designed, persisting independently of SDF infrastructure while other validators and archived ledger history maintained continuity.
