The Tail at Scale by Jordan West :: SysDesign Meetup :: 2025-Aug-14 скачать в хорошем качестве

The Tail at Scale by Jordan West :: SysDesign Meetup :: 2025-Aug-14

Jordan West is an Engineering Manager at Netflix and a Cassandra committer. He’s worked on large scale deployments of Cassandra for the past 7 years and distributed databases for the past 10. He is passionate about growing the Cassandra community and working on large scale distributed systems. Jordan:   / jordan-west-8aa1731a3   The Paper, Tail at Scale, by Jeffrey Dean & Luiz André Barroso: https://dl.acm.org/doi/pdf/10.1145/24... 0:00 Why tail latency matters for users 0:23 Cost-effective latency reduction vs. overprovisioning 1:02 Sources of variability (noisy neighbors, background tasks, GC) 3:47 More machines: more chance of tail latency 5:00 Why 99th latency percentile matters 6:04 Classifying and prioritizing requests 7:20 Real-world example: Cassandra 9:22 Priority queues in production 10:05 Two queues as a special case of priority queue 12:08 QoS vs. throttling terminology 16:06 Time slicing and reducing head-of-line blocking 21:22 Synchronizing vs. jittering background work 24:34 Hedged requests, speculative retries, pitfalls 34:49 Tied requests and why writes are different 37:00 Micro-partitions and a note on consistent hashing 39:44 Probation and metrics: avoiding slow nodes 45:04 Canary requests and cross-request monitoring 46:24 Writes vs. reads, practical takeaways 47:19 Applying these ideas to APIs, DBs, and frontends 47:31 Closing and Q&A