Solana’s blockchain recently faced a prolonged outage, prompting experts to expose critical vulnerabilities in how the popular blockchain network functioned when it comes to validating transactions.
Per the site, while the network was offline for 17 hours, no funds were lost, and the network returned to full functionality in under 24 hours, and that Solana is designed for adversarial conditions. Notably, its native token fell by almost 15 percent over the last 7 days to its current value at around $136, having witnessed a massive rally of about 700 percent over the last few weeks.
What happened?
Per Solana’s official statement, “the cause of the network stall was a denial of service attack. At 12:00 UTC, Grape Protocol launched their IDO on Raydium, and bots generated transactions that flooded the network. These transactions created a memory overflow, which caused many validators to crash forcing the network to slow down and eventually stall. The network went offline when the validator network could not agree on the current state of the blockchain, which prevented the network from confirming new blocks".
Amidst a network slowdown and a substantial transaction spike, “the forwarder queue system flooded uncontrollably, causing the memory used by this queue to grow without limits. The transactions that were encoded into blocks were extremely resource-heavy to process.
“The combination of the unbounded growth of the forwarder queues and resource-heavy blocks caused block producers to automatically propose several forks. The validator processes started to run out of memory and crash, and upon restart, the validators were unable to process all the proposed forks in time to catch back up with the rest of the network,” Solana elaborated, and hence the extended duration of the blackout.
Key flaws in network design
Douglas Horn, Chief Architect of Telos Blockchain, pointed out that blockchains should never stall if designed well and that substantial flaws lie at the core of the lighting-fast speed of transaction processing (1,828 live transactions per second) as claimed by Solana.
“A great portion of Solana transactions is not the user or smart contract transactions that networks like Ethereum (15 TPS) and Telos (10,000 TPS) process but instead include Solana’s thousands of critical consensus messages required by the chain. These processes are typically handled separately from on-chain transactions via a distinct communications channel--for good reason. This differing design results in seemingly amazing scalability claims, which are entirely misleading. It's this design that forms a large part of why the Solana chain was locked up for over 12 hours,” Horn detailed.
Adding to that, the chain’s lack of prioritisation capabilities and immature fee model design means that when critical consensus messaging and regular transactions are mixed and Solana transaction queues are flooded, the processing of the former is displaced causing a lack of syncing between nodes and eventually the forking that resulted in a stalled network. Such a mix also results in inflated transactions per second, but more critically exposes a large surface area of attacks on the blockchain
“The best avoidance of this and other potential issues would be not to have these transactions mixed. Nonetheless, prioritisation of transactions was a factor yesterday that could have helped avoid Solana stalling from this specific exploit”, Horn further said.
Solana vs Ethereum?
While such an outage can negatively impact the project image and outcomes, noted the Coin DCX research team, some experts remain optimistic about the prospects of Solana, given its high energy efficiency and cost-effectiveness.
Edul Patel, CEO & Co-founder, Mudrex, pointed out that while the 17- hour outage did cause unrest among a large section of retail investors, "SOL continues to gain traction among institutional investors, given that a significant portion of SOL tokens in circulation is held by institutional investors and only a small percentage of it rests with the retail holders".
The popularity of the Solana blockchain can be fundamentally attributed to superfast transactions and dirt cheap transaction fees. “It is highly likely that Solana will take up all the blockchain gaming activity, which is computationally intensive, including payment transactions activity. It has the potential to compete with alto solutions, side chains on Eetherium Matic, Arbitrum, Optimism, among others. It would be interesting to see how it evolves in the future,” mentioned Gaurav Dahake, Founder & CEO, Bitbns.
Vikram Subburaj, Co-founder and CEO of Giottus Cryptocurrency Exchange, highlights the need for multiple layer 1 solutions to tackle network congestion. “With strong weekly inflows from institutional investors as well as adoption as a non-fungible token (NFT) platform, it faced network congestion back in August as well, leading to questions about its decentralised nature and a sudden diversion of interest towards another layer 1 solutions such as Avalanche. We believe that multiple layer 1 solutions will co-exist in the future and hence, Solana is well-positioned as of now,” he explained.
