8.8-M03

This is the third Milestone of Redis 8.8 in Redis Open Source.

Milestones are non-feature-complete pre-releases. Pre-releases are not suitable for production use.

Headlines:

Redis 8.8 introduces new features and performance improvements.

Operating systems we test Redis 8.8 on

• Ubuntu 22.04 (Jammy Jellyfish), 24.04 (Noble Numbat), 26.04 (Resolute Raccoon)
• Rocky Linux 8.10, 9.7, 10.1
• AlmaLinux 8.10, 9.7, 10.1
• Debian 12.13 (Bookworm), Debian 13.4 (Trixie)
• Alpine 3.23
• macOS 14.8.4 (Sonoma), 15.7.4 (Sequoia), 26.3 (Tahoe) - for both Intel and ARM

New Features (compared to 8.8-M02)

• #14958 Subkey notification for hash fields - field-level notifications
• RediSearch/RediSearch#8227 FT.HYBRID KNN clause: new argument to request fewer candidates per shard
• RediSearch/RediSearch#8060 FT.PROFILE HYBRID: profiling support for FT.HYBRID

Bug fixes (compared to 8.8-M02)

• #15034, #15081 Issues processing corrupt RDB data
• #15059 Use-after-free
• #15073 CLIENT TRACKING: self-overlap returning non-zero loop index
• #14982 SCAN commands: integer overflow in COUNT parameter
• #14956 Crash on HSETEX when a field appears more than once and an expiry is specified
• #15015 Change log level for unknown extension types from LL_WARNING to LL_VERBOSE
• #14995 Unnecessary -ERR and \r\n
• RediSearch/RediSearch#8708 Crash when many keys receive expirations under heavy TTL activity
• RediSearch/RediSearch#8774 Coordinator deadlock under mixed FT.SEARCH and FT.AGGREGATE load
• RediSearch/RediSearch#8415 Crash on FT.SEARCH when topology validation fails (for example, some nodes unreachable)
• RediSearch/RediSearch#8322 Crash when indexing negative zero (-0.0)
• RediSearch/RediSearch#8843 HNSW vector index memory growth under high-churn workloads until shard restart
• RediSearch/RediSearch#8396 FILTER returns inconsistent results with multiple indexes sharing field aliases
• RediSearch/RediSearch#8205 FT.HYBRID VSIM RANGE + FILTER incorrectly returns zero results
• RediSearch/RediSearch#8817 Instability and crashes in long-running search cursors during concurrent index updates
• RediSearch/RediSearch#8388 FT.SEARCH fails with “Query requires unavailable slots” after shard restart or failover
• RediSearch/RediSearch#8548 FILTER behavior depends on property order in the expression
• RediSearch/RediSearch#8320 Index FILTER applied inconsistently when documents are missing filtered fields
• RediSearch/RediSearch#8752 Missing blocked-client FAIL timeout mechanism for coordinator-level FT.AGGREGATE
• RediSearch/RediSearch#8657 Missing shard-level FAIL timeout handling for FT.HYBRID queries
• RediSearch/RediSearch#8420 Missing coordinator-level FAIL timeout handling for FT.HYBRID queries
• RediSearch/RediSearch#8335 Legacy shard-level FAIL handling for FT.SEARCH / FT.AGGREGATE
• RediSearch/RediSearch#8191 FT.SEARCH coordinator lacks strict FAIL timeout enforcement

Performance and resource utilization improvements (compared to 8.8-M02)

• #15114 Optimize SET key value GET
• #15065, #15118 Scan commands key collection: replace list with append-only pointer vector
• #15061 Widen fast_float_strtod fast path to 17-19 digit mantissas
• RediSearch/RediSearch#8378 Optimize filter expression evaluation: skip indexes not matching the document type (MOD-14064)

Metrics (compared to 8.8-M02)

• RediSearch/RediSearch#8246 ‘frontend_buffer_size’, ‘HNSW_main_thread_insertion’: metrics for tiered vector indexes (MOD-13819)
• RediSearch/RediSearch#8210 FT.PROFILE: added queue time tracking (MOD-13602)
• RediSearch/RediSearch#8283 INFO: Skip metrics when there are no indices (MOD-13903)
• RediSearch/RediSearch#7417 Add unique error message ids for improved debugging and troubleshooting (MOD-11806)

Configuration parameters

• RediSearch/RediSearch#8876 search-workers: change default to 16 (MOD-14486)
• RediSearch/RediSearch#8352 BG_INDEX_SLEEP_DURATION_US: sleep duration during background indexing (MOD-13994)