A failure at provider TeraSwitch nearly halted the Solana network: the critical finalization threshold was within reach.
On August 12, an infrastructure failure at provider TeraSwitch pushed the Solana network to the brink of halting finalization. The simultaneous disconnection of validators controlling 28.83% of all staked SOL brought the figure close to the critical threshold of 33.34%, beyond which the blockchain stops confirming transactions. This event, which I track as part of network resilience monitoring, affected about 90 validators.
TeraSwitch's autonomous system AS20326, which accounted for 118.9 million SOL (27.34% of total stake), became the epicenter of the problem. During the incident, 94% of that amount went offline simultaneously—an unprecedented level of risk concentration. Fortunately, the critical threshold was not reached: routing was restored in about 33 minutes, and validators returned to the network. During the downtime, they missed out on approximately 333 SOL in rewards—a relatively small amount, but the very fact of such a close call with disaster is alarming.
Infrastructure concentration—a systemic threat
This incident is not a coincidence but a natural outcome of a long-standing issue. As early as July 22, TeraSwitch hosted validators with 27.1% of Solana's locked tokens. It was followed by UAB Cherry Servers (12.7%) and Latitude.sh (11%). Such concentration makes the network vulnerable to single points of failure, contradicting the very idea of decentralization.
The Marinade Finance team has already announced a review of restrictions on the distribution of validators across autonomous systems and data centers. However, some major operators are acting proactively. For example, Coinbase reported in its first-quarter report that 13 of its validators operate through TeraSwitch, another 10 through Latitude, but each uses a backup server in a different location. This is a sensible strategy that should be scaled across the entire ecosystem.
Historical context only heightens concern. In November 2022, Hetzner shut down servers hosting Solana nodes, affecting about 40% of validators with 20% of the stake—the network survived then. But the situation now is different: the number of active validators has dropped to 800 (a minimum since 2021), while at the peak in 2023 there were over 2,500. Fewer validators mean higher risk concentration.
My conclusion: Solana has once again demonstrated resilience, but this case is a stark signal for the entire market. Infrastructure diversification must become a priority; otherwise, the next failure could be fatal. Investors should closely monitor stake distribution, not just the asset's price.