Dragonfly 2.0 adds Valkey 9 RDB loading and makes connection memory accounting constant time

Sources: v2.0.0 release notes, Phoronix report, HN submission
Summary: The release notes name operational changes rather than a version bump. Dragonfly 2.0 was published 2026-09-16, so it predates this page. It loads RDB files written by Valkey 9, connection memory introspection drops from O(n) to O(1), and the default maximum client input buffer halves from 64 KiB to 32 KiB. RDB serializer buffers are capped at 4 MiB after flushing, where a 512 MiB object previously left 512 MiB allocated. RESTORE now rejects payloads whose declared lengths exceed the remaining input, which the notes say prevents remote out-of-memory crashes.
Why it matters: The serializer buffer cap and the RESTORE length check close two paths by which one large or malformed payload drives a Dragonfly node out of memory.