Arista Networks EOS Evolution and Quality with Ken Duda

Ken Duda, Founder, CTO, and Senior VP of Software Engineering at Arista Networks, delivered a compelling presentation on the evolution and quality of Arista’s EOS software platform. Recorded on August 20, 2015, Duda emphasized that quality is the paramount concern for Arista, not just one of many priorities. He explained that the reliability of network software is crucial because when the network fails, everything else does too. From the inception of Arista, the company has focused on delivering a higher quality network experience by prioritizing quality through three main pillars: culture, architecture, and testing.

Duda elaborated on the cultural aspect of quality, highlighting that at Arista, quality is ingrained in the company’s ethos. Unlike some competitors who might incentivize hitting ship dates with bonuses, Arista does not reward employees for meeting deadlines if it compromises quality. This approach ensures that employees are not pressured to release products prematurely. Duda shared an anecdote about how the CEO, Jayshree Ullal, consistently supports delaying shipments to ensure the product is ready, thereby shifting the risk from the customer’s balance sheet to Arista’s income statement. This cultural commitment to quality extends to how the company handles customer issues. Technical engineers are empowered to directly contact technical leads to resolve problems without bureaucratic escalation, ensuring swift and effective responses to any issues in the field.

On the architectural front, Duda discussed how Arista’s use of Pure Linux and a system database approach contributes to the robustness of their software. By adhering to the Unix philosophy and avoiding kernel modifications, Arista maintains compatibility with the broader Linux community and ensures easier upgrades. The system database approach replaces traditional message passing, which can lead to synchronization and update rate mismatch problems. Instead, Arista’s architecture allows for state-oriented updates, coalescing changes to maintain system stability even under high-stress conditions. Finally, Duda addressed the importance of testing, advocating for the elimination of traditional QA teams in favor of automated testing. Each development team at Arista is responsible for the quality of their code, providing both the new code and the automated tests to prove its functionality. This rigorous testing framework has significantly reduced regressions and improved the overall quality of Arista’s software, ensuring that customers experience fewer issues and more reliable network performance.