Latency
4 engineering logs on Latency. Newest first.
- Service mesh: what it buys and the latency it charges
What a sidecar actually costs per hop, why the honest comparison is against the libraries it replaces rather than against nothing, and why the operational burden lands on the team least able to debug it.
- Your p99 is a garbage collector setting
Why a tail latency that no profiler explains is usually a stop the world pause, why allocation rate matters more than heap size, and why a bigger heap can make the tail worse.
- Why your Redis is slow: it is single threaded and you sent it KEYS
Why one O(N) command blocks every other client on the server, which everyday commands are secretly linear, and why a p99 spike with flat CPU is almost always somebody scanning the keyspace.
- Your ORM issued 400 queries and the p99 looked fine until it didn't
Why N+1 queries are invisible to every database side metric you own, how a getter call becomes a network round trip, and why the fix that looks obvious produces a cartesian product.