2.5.27

• Adds: a backlog/retry mechanism for commands issued while a connection isn't available (#1912 by @NickCraver)
  • Commands will be queued if a multiplexer isn't yet connected to a Redis server.
  • Commands will be queued if a connection is lost and then sent to the server when the connection is restored.
  • All commands queued will only remain in the backlog for the duration of the configured timeout.
  • To revert to previous behavior, a new ConfigurationOptions.BacklogPolicy is available - old behavior is configured via options.BacklogPolicy = BacklogPolicy.FailFast. This backlogs nothing and fails commands immediately if no connection is available.
• Adds: Makes StreamEntry constructor public for better unit test experience (#1923 by @WeihanLi)
• Fix: Integer overflow error (issue #1926) with 2GiB+ result payloads (#1928 by @mgravell)
• Change: Update assumed redis versions to v2.8 or v4.0 in the Azure case (#1929 by @NickCraver)
• Fix: Profiler showing EVAL instead EVALSHA (#1930 by @martinpotter)
• Performance: Moved tiebreaker fetching in connections into the handshake phase (streamline + simplification) (#1931 by @NickCraver)
• Stability: Fixed potential disposed object usage around Arenas (pulling in Piplines.Sockets.Unofficial#63 by @mgravell)
• Adds: Thread pool work item stats to exception messages to help diagnose contention (#1964 by @NickCraver)
• Fix/Performance: Overhauls pub/sub implementation for correctness (#1947 by @NickCraver)
  • Fixes a race in subscribing right after connected
  • Fixes a race in subscribing immediately before a publish
  • Fixes subscription routing on clusters (spreading instead of choosing 1 node)
  • More correctly reconnects subscriptions on connection failures, including to other endpoints
• Adds "(vX.X.X)" version suffix to the default client ID so server-side CLIENT LIST can more easily see what's connected (#1985 by @NickCraver)
• Fix: Properly including or excluding key names on some message failures (#1990 by @NickCraver)
• Fix: Correct return of nil results in LPOP, RPOP, SRANDMEMBER, and SPOP (#1993 by @NickCraver)

2.2.88

• Change: Connection backoff default is now exponential instead of linear (#1896 by @lolodi)
• Adds: Support for NodeMaintenanceScaleComplete event (handles Redis cluster scaling) (#1902 by @NickCraver)

2.1.28

• Fix: Stability in new sentinel APIs
• Fix #1407: Include SslProtocolos in ConfigurationOptions.ToString() (#1408 by @vksampath and Sampath Vuyyuru)
• Fix: Clarify messaging around disconnected multiplexers (#1396 by @NickCraver)
• Change: Tweak methods of new sentinel API (this is technically a breaking change, but since this is a new API that was pulled quickly, we consider this to be acceptable)
• Adds: New thread SocketManager mode (opt-in) to always use the regular thread-pool instead of the dedicated pool
• Adds: Improved counters in/around error messages
• Adds: New User property on ConfigurationOptions
• Build: Enable deterministic builds (note: this failed; fixed in 2.1.30)

2.0.600

• Adds: ulong support to RedisValue and RedisResult (#1104 by @mgravell)
• Fix: Remove odd equality: "-" != 0 (we do, however, still allow "-0", as that is at least semantically valid, and is logically == 0) (related to #1103)
• Performance: Rework how pub/sub queues are stored - reduces delegate overheads (related to #1101)
• Fix #1108: Ensure that we don't try appending log data to the TextWriter once we've returned from a method that accepted one

2.6.86

• Fix #1520 & #1660: When MOVED is encountered from a cluster, a reconfigure will happen proactively to react to cluster changes ASAP (#2286 by @NickCraver)
• Fix #2249: Properly handle a fail state (new ClusterNode.IsFail property) for CLUSTER NODES and expose fail? as a property (IsPossiblyFail) as well (#2288 by @NickCraver)
• Adds: IConnectionMultiplexer.ServerMaintenanceEvent (was on ConnectionMultiplexer but not the interface) (#2306 by @NickCraver)
• Adds: To timeout messages, additional debug information: Sync-Ops (synchronous operations), Async-Ops (asynchronous operations), and Server-Connected-Seconds (how long the connection in question has been connected, or "n/a") (#2300 by @NickCraver)

2.6.80

• Adds: last-in and cur-in (bytes) to timeout exceptions to help identify timeouts that were just-behind another large payload off the wire (#2276 by @NickCraver)
• Adds: general-purpose tunnel support, with HTTP proxy "connect" support included (#2274 by @mgravell)
• Removes: Package dependency (System.Diagnostics.PerformanceCounter) (#2285 by @NickCraver)

2.6.70

• Fix: MOVED with NoRedirect (and other non-reachable errors) should respect the IncludeDetailInExceptions setting (#2267 by @mgravell)
• Fix #2251 & #2265: Cluster endpoint connections weren't proactively connecting subscriptions in all cases and taking the full connection timeout to complete as a result (#2268 by @iteplov)

2.6.66

• Fix #2182: Be more flexible in which commands are "primary only" in order to support users with replicas that are explicitly configured to allow writes (#2183 by @slorello89)
• Adds: IConnectionMultiplexer now implements IAsyncDisposable (#2161 by @kimsey0)
• Adds: IConnectionMultiplexer.GetServers() to get all IServer instances for a multiplexer (#2203 by @NickCraver)
• Fix #2016: Align server selection with supported commands (e.g. with writable servers) to reduce Command cannot be issued to a replica errors (#2191 by @slorello89)
• Performance: Optimization around timeout processing to reduce lock contention in the case of many items that haven't yet timed out during a heartbeat (#2217 by @NickCraver)
• Fix #2223: Resolve sync-context issues (missing ConfigureAwait(false)) (#2229 by @mgravell)
• Fix #1968: Improved handling of EVAL scripts during server restarts and failovers, detecting and re-sending the script for a retry when needed (#2170 by @martintmk)
• Adds: ConfigurationOptions.SslClientAuthenticationOptions (netcoreapp3.1/net5.0+ only) to give more control over SSL/TLS authentication (#2224 by @NickCraver)
• Fix #2240: Improve support for DNS-based IPv6 endpoints (#2241 by @NickCraver)
• Adds: ConfigurationOptions.HeartbeatInterval (Advanced Setting - see docs) To allow more finite control of the client heartbeat, which encompases how often command timeouts are actually evaluated - still defaults to 1,000 ms (#2243 by @NickCraver)
• Fix #1879: Improve exception message when the wrong password is used (#2246 by @NickCraver)
• Fix #2233: Repeated connection to Sentinel servers using the same ConfigurationOptions would fail (#2242 by @NickCraver)

2.6.48

• URGENT Fix: #2167, #2176: fix error in batch/transaction handling that can result in out-of-order instructions (#2177 by @mgravell)
• Fix: #2164: fix LuaScript.Prepare for scripts that don't have parameters (#2166 by @mgravell)

2.6.45

• Adds: Nullable reference type annotations (#2041 by @NickCraver)
  • Adds annotations themselves for nullability to everything in the library
  • Fixes a few internal edge cases that will now throw proper errors (rather than a downstream null reference)
  • Fixes inconsistencies with null vs. empty array returns (preferring an not-null empty array in those edge cases)
  • Note: does not increment a major version (as these are warnings to consumers), because: they're warnings (errors are opt-in), removing obsolete types with a 3.0 rev would be binary breaking (this isn't), and reving to 3.0 would cause binding redirect pain for consumers. Bumping from 2.5 to 2.6 only for this change.
• Adds: Support for COPY with .KeyCopy()/.KeyCopyAsync() (#2064 by @Avital-Fine)
• Adds: Support for LMOVE with .ListMove()/.ListMoveAsync() (#2065 by @Avital-Fine)
• Adds: Support for ZRANDMEMBER with .SortedSetRandomMember()/.SortedSetRandomMemberAsync(), .SortedSetRandomMembers()/.SortedSetRandomMembersAsync(), and .SortedSetRandomMembersWithScores()/.SortedSetRandomMembersWithScoresAsync() (#2076 by @Avital-Fine)
• Adds: Support for SMISMEMBER with .SetContains()/.SetContainsAsync() (#2077 by @Avital-Fine)
• Adds: Support for ZDIFF, ZDIFFSTORE, ZINTER, ZINTERCARD, and ZUNION with .SortedSetCombine()/.SortedSetCombineAsync(), .SortedSetCombineWithScores()/.SortedSetCombineWithScoresAsync(), and .SortedSetIntersectionLength()/.SortedSetIntersectionLengthAsync() (#2075 by @Avital-Fine)
• Adds: Support for SINTERCARD with .SetIntersectionLength()/.SetIntersectionLengthAsync() (#2078 by @Avital-Fine)
• Adds: Support for LPOS with .ListPosition()/.ListPositionAsync() and .ListPositions()/.ListPositionsAsync() (#2080 by @slorello89)
• Adds: Support for ZMSCORE with .SortedSetScores()/.SortedSetScoresAsync() (#2082 by @ttingen)
• Adds: Support for NX | XX | GT | LT to EXPIRE, EXPIREAT, PEXPIRE, and PEXPIREAT with .KeyExpire()/.KeyExpireAsync() (#2083 by @Avital-Fine)
• Adds: Support for EXPIRETIME, and PEXPIRETIME with .KeyExpireTime()/.KeyExpireTimeAsync() (#2083 by @Avital-Fine)
• Fix: For streams, properly hash XACK, XCLAIM, and XPENDING in cluster scenarios to eliminate MOVED retries (#2085 by @nielsderdaele)
• Adds: Support for OBJECT REFCOUNT with .KeyRefCount()/.KeyRefCountAsync() (#2087 by @Avital-Fine)
• Adds: Support for OBJECT ENCODING with .KeyEncoding()/.KeyEncodingAsync() (#2088 by @Avital-Fine)
• Adds: Support for GEOSEARCH with .GeoSearch()/.GeoSearchAsync() (#2089 by @slorello89)
• Adds: Support for GEOSEARCHSTORE with .GeoSearchAndStore()/.GeoSearchAndStoreAsync() (#2089 by @slorello89)
• Adds: Support for HRANDFIELD with .HashRandomField()/.HashRandomFieldAsync(), .HashRandomFields()/.HashRandomFieldsAsync(), and .HashRandomFieldsWithValues()/.HashRandomFieldsWithValuesAsync() (#2090 by @slorello89)
• Adds: Support for LMPOP with .ListLeftPop()/.ListLeftPopAsync() and .ListRightPop()/.ListRightPopAsync() (#2094 by @slorello89)
• Adds: Support for ZMPOP with .SortedSetPop()/.SortedSetPopAsync() (#2094 by @slorello89)
• Adds: Support for XAUTOCLAIM with .StreamAutoClaim()/.StreamAutoClaimAsync() and .StreamAutoClaimIdsOnly()/.StreamAutoClaimIdsOnlyAsync() (#2095 by @ttingen)
• Fix #2071: Add .StringSet()/.StringSetAsync() overloads for source compat broken for 1 case in 2.5.61 (#2098 by @NickCraver)
• Fix #2086: Correct HashSlot calculations for XREAD and XREADGROUP commands (#2093 by @nielsderdaele)
• Adds: Support for LCS with .StringLongestCommonSubsequence()/.StringLongestCommonSubsequence(), .StringLongestCommonSubsequenceLength()/.StringLongestCommonSubsequenceLengthAsync(), and .StringLongestCommonSubsequenceWithMatches()/.StringLongestCommonSubsequenceWithMatchesAsync() (#2104 by @Avital-Fine)
• Adds: Support for OBJECT FREQ with .KeyFrequency()/.KeyFrequencyAsync() (#2105 by @Avital-Fine)
• Performance: Avoids allocations when computing cluster hash slots or testing key equality (#2110 by @mgravell)
• Adds: Support for SORT_RO with .Sort()/.SortAsync() (#2111 by @slorello89)
• Adds: Support for BIT | BYTE to BITCOUNT and BITPOS with .StringBitCount()/.StringBitCountAsync() and .StringBitPosition()/.StringBitPositionAsync() (#2116 by @Avital-Fine)
• Adds: Support for pub/sub payloads that are unary arrays (#2118 by @mgravell)
• Fix: Sentinel timer race during dispose (#2133 by @ewisuri)
• Adds: Support for GT, LT, and CH on ZADD with .SortedSetAdd()/.SortedSetAddAsync() and .SortedSetUpdate()/.SortedSetUpdateAsync() (#2136 by @Avital-Fine)
• Adds: Support for COMMAND COUNT, COMMAND GETKEYS, and COMMAND LIST, with .CommandCount()/.CommandCountAsync(), .CommandGetKeys()/.CommandGetKeysAsync(), and .CommandList()/.CommandListAsync() (#2143 by @shacharPash)