capacity-planning

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spotify

Content Ingestion & Podcast Video Incident Report | Spotify Engineering (opens in new tab)

Spotify’s June 24 publishing incident delayed video podcast episodes for several hours after transcoding capacity was overwhelmed. The disruption resulted from insufficient capacity headroom, a concurrent batch job, increased processing costs, and a scheduling bug that reduced throughput by about 10%. Spotify cleared the backlog by the following morning and has since expanded capacity, improved monitoring, and launched a broader publishing reliability initiative. ## What Caused the Delay - A spike in new video podcast submissions pushed transcoding infrastructure close to its maximum capacity. - A scheduled batch job was reprocessing existing episodes, consuming capacity needed for new publications. - Recent video-quality improvements increased the processing time and compute required per episode. - A resource-scheduling bug following an infrastructure migration underused available hardware, reducing throughput by approximately 10%. - Creators re-uploaded missing episodes, unintentionally adding more load because Spotify did not clearly confirm that uploads had been received and queued. ## Incident Timeline and Response - Early monitoring alerts fired at 13:30 UTC, but they were not initially recognized as a broader capacity problem. - At 15:00, a delivery spike brought transcoding close to capacity. - The batch job was stopped at 16:35 to free resources. - Formal incident response began at 17:34 after queue thresholds were exceeded. - A scheduling fix was deployed at 20:49, and an additional processing cluster came online at 00:14 on June 25. - All queues were cleared by 01:02, with normal pipeline operation confirmed at 07:30. - Approximately four hours passed between the first alerts and formal incident response, highlighting a major monitoring and escalation gap. ## Remediation Measures - Spotify increased transcoding capacity by approximately 67% to provide more room for traffic spikes and batch processing. - The resource-scheduling bug was fixed, restoring use of previously underutilized compute capacity. - Monitoring was improved to warn earlier when capacity is approaching operational limits. ## Broader Reliability Program - Capacity planning is being expanded to account for burst traffic, background workloads, and recovery needs—not only typical steady-state demand. - Publishing systems will prioritize real-time creator uploads over background operations. - Spotify is extending rate limiting and backpressure mechanisms across the pipeline so unexpected load can be handled more gracefully. - A dedicated cross-team effort is coordinating these improvements across the publishing infrastructure. Spotify’s main lesson is that reliable publishing requires both additional capacity and better operational safeguards. Earlier detection, clearer upload acknowledgments, stronger workload prioritization, and deliberate burst-capacity planning should reduce the likelihood and impact of similar incidents.