Go 1.28 HTTP/2 parking cuts server memory ~40% at 5,000 idle connections

Draft Go 1.28 release notes reveal an HTTP/2 server change called parking: the connection's serving goroutine can exit when idle and a new one takes over when work arrives. Benchmarks on the same Go 1.28 binary showed RSS dropping by 84.7–92.6 MiB (about 39–41%) at 5,000 idle connections, with exactly 5,000 fewer goroutines.

• RSS at 5,000 idle connections: ~130 MiB with parking vs ~220 MiB without
• Goroutine count: 5,007 with parking vs 10,007 without
• StackInuse fell from ~99 MiB to ~21 MiB, saving about 78 MiB
• At 1,000 connections RSS savings were 15.7–16.6 MiB