40One anycast prefix announced from six sites. What does that buy you, and what breaks at 3am?▼mediumNewCloudflareAmazon & AWSGoogle◆ premiumAnycast turns BGP convergence into your failover mechanism. Sessions stick to the site they landed on, monitoring must go per-site, and a route you cannot withdraw cleanly is worse than DNS.Open full answer →
12DNS failover with health checks is configured between two regions, yet users saw minutes of downtime. Why is it slower than it looks?▼mediumNewAmazon & AWSCloudflareSalesforce○ sign inDNS failover is a blunt instrument with three delays stacked on top of each other: detection, propagation and client caching. Knowing their sizes tells you when DNS is the right layer at all.Open full answer →
33One app instance keeps flapping out of the load balancer pool, yet between bursts it serves traffic happily. Where do you look?▼mediumNewLinkedInNetflixAtlassian◆ premiumSelf-healing unavailability is a timeout arithmetic story. Pull the balancer's removal timestamps, lay them against the GC log, and the pause that ejects the instance will be sitting there in plain sight.Open full answer →
