dragonflydb/dragonfly v1.40.2 on GitHub

Tiered storage (disk offload)

fix(tiering): Don't cool on load — values loaded during full sync / RDB-DFS load were incorrectly pushed into the cool-tier cache; loading is no longer treated as a candidate for cooling since it isn't client traffic.
fix(tiering): Replace the separate write-depth limit with a single tiered_max_pending_bytes cap that covers both in-flight reads and writes, and export read/write/total usage as metrics.
fix(tiering): Add tiered_serialization_inflight_bytes_cap — snapshot serialization now throttles/waits when there are too many outstanding tiered reads, preventing unbounded memory growth from delayed entries during snapshotting.
fix: Bound small-bins traversal with TraverseBySegmentOrder (same class of fix as DeleteExpiredStep in #8129), preventing entries from being skipped or revisited when the table resizes mid-scan; also exports additional tiering metrics/settings.
fix: Export small-bin entries-bytes usage in metrics/INFO.
feat(tiering): Add a background "repack scan" that repacks small-bins buckets with excessive wasted space; disabled by default (tiered_repack_scan_budget_us=0).

Replication / journal

fix(server): Bound DeleteExpiredStep traversal with TraverseBySegmentOrder (#8129)
fix(server): Fix journal omit breaking on stash bucket (#8157)
fix(server): Split the "journal omit" optimization into two independent decisions — skipping forced snapshot serialization vs. skipping the journal write — since the former no longer requires the latter; also adds TTL propagation for EXPIRE writes that skip serialization.
backport(cluster): Fix memory-accounting bug and journal FLUSHSLOTS from inside the flush transaction, avoiding replication inconsistency during slot migration (#8061, backports #8032)

Protocol

fix(facade): Reject memcached keys longer than the 250-byte protocol limit (#8213). Previously, a long key (e.g. written via the Redis port) could be echoed back unbounded in a memcached VALUE reply, overflowing the reply buffer.

Advisory: it is advised to upgrade to this release due to the correctness bug with journaling #8157