Redis 3.0 release notes ======================= WARNING: Redis 3.0 is currently a BETA not suitable for production environments. -------------------------------------------------------------------------------- Upgrade urgency levels: LOW: No need to upgrade unless there are new features you want to use. MODERATE: Program an upgrade of the server, but it's not urgent. HIGH: There is a critical bug that may affect a subset of users. Upgrade! CRITICAL: There is a critical bug affecting MOST USERS. Upgrade ASAP. -------------------------------------------------------------------------------- --[ Redis 3.0.0 Beta 6 (version 2.9.55) ] Release date: 9 jun 2014 This is the 6th beta of Redis 3.0.0. >> General changes * [FIX] Fix software watchdog signal handler crash due to re-entering. * [FIX] Better Lua number -> string conversion for Lua scripts. * [FIX] Serious replication bug when min-slaves-* feature is used in slaves configuration fixed. * [FIX] Blocking pop on lists now works when the list is created by commands other than *PUSH* (for example SORT STORE). >> Cluster changes * [FIX] CRITICAL: For a bug in the implementation of CLUSTER SET-CONFIG-EPOCH introduced with beta-3 (especially beta-4 where the command is actually used by redis-trib), a configEpoch for a node could jump backward, breaking the eventual consistency property of the slots -> nodes mapping in the cluster. >> Sentinel changes * No changes for Sentinel in this release. --[ Redis 3.0.0 Beta 5 (version 2.9.54) ] Release date: 26 may 2014 This is the 5th beta of Redis 3.0.0. It does not include any real worthwhile change (just three days passed since the previous beta), but fixes two stupid bugs preventing cluster tests to pass. --[ Redis 3.0.0 Beta 4 (version 2.9.53) ] Release date: 23 may 2014 This is the fourth beta of Redis 3.0.0. >> General changes * [NEW] Scripting engine performances improvements. * [NEW] Log format slightly changed to report current node role. * [FIX] Correct the HyperLogLog stale cache flag to prevent unnecessary computation. >> Cluster changes * [NEW] redis-trib: ability to import data from standalone Redis instances. * [NEW] redis-trib: "fix" subcommand much better at fixing errors. * [NEW] CLUSTER FAILOVER FORCE implemented. * [NEW] CLUSTER RESET implemented, it is now possible to completely reset nodes and create a new cluster without restarting anything. * [NEW] Slave validity factor (max estimated data age to still failover) is now under the control of the user, and can be configured via redis.conf or CONFIG SET. Option name cluster-slave-validity-factor. * [NEW] Cluster test: failure detection and failover initial tests. * [NEW] CLUSTER MEET: better error messages when address is invalid. * [NEW] Bulk-accept new Cluster nodes in the Cluster bus instead of performing just a single accept() per event fired. * [FIX] Bypass data_age check for manual failovers. * [FIX] Fixed data_age computation / check integer overflow. * [FIX] Various fixes to Tcl client.tcl Redis Cluster client used in tests. * [FIX] Better handling of stolen slots. * [FIX] Don't accept cluster bus connections during startup. >> Sentinel changes * [NEW] Generate +config-update-from event when a new config is received. * [NEW] Log when a failover will be re-attempted again. * [FIX] Sentinel: Add "dir /tmp" directive in example sentinel.conf. --[ Redis 3.0.0 Beta 3 (version 2.9.52) ] Release date: 5 may 2014 This is the third beta of Redis 3.0.0. >> General changes * [NEW] New data structure: the HyperLogLog (see 2.8 release notes). * [NEW] Lexicograhical range queries in sorted sets (see 2.8 release notes). * [NEW] LRU algorithm precision greatly improved. * [FIX] Redis is now much more responsive to reply with LOADING / BUSY errors. >> Cluster changes * [NEW] Cluster testing framework and initial tests. * [NEW] Cluster epochs collision resolution (make Redis Cluster more resilient to admin and programming errors). * [NEW] Persist / fsync some global state to ensure correct crash-recovery semantics. * [NEW] New command introduced: CLUSTER SET-CONFIG-EPOCH, still not used by redis-trib. Will be used to speedup the assignment of unique epochs to different nodes at cluster creation time. For now this is handled as a side effect of the cluster epochs collision resolution. * [FIX] Different fixes to redis-trib cluster creation. * [FIX] Fix an error in the CLUSTER NODES output for nodes slots. >> Sentinel changes * [NEW] Sentinels are now able to send update messages in a peer-to-peer fashion even if no Redis instances are available. Now the Sentinel liveness property that the most updated configuration in a given partition is propagated to all the Sentinels is extended to partitions without reachable instances. * [NEW] Sentinel safety properties are now ensured in a crash-recovery system model since some state is persisted on disk before replying to other nodes, and reloaded at startup. * [NEW] Sentinel now uses CLIENT SETNAME so that it is easy to identify Sentinels using CLIENT LIST among other clients. * [NEW] Sentinel failure detection and reconnection code improved. --[ Redis 3.0.0 Beta 2 (version 2.9.51) ] Release date: 11 mar 2014 This is the second beta of Redis 3.0.0. >> General changes * [FIX] Sometimes the absolute config file path was obtained in a wrong way. This happened when there was a "dir" directive inside the config file and at the same time the configuration file was given as a relative path to redis-server or redis-sentinel executables. * [FIX] redis-cli: Automatically enter --slave mode when SYNC or PSYNC are called during an interactive session. * [FIX] BITCOUNT: fixed unaligned access causing issues in sparc and other archs not capable of dealing with unaligned accesses. This also makes the code faster in archs where unaligned accesses are allowed. * [FIX] Force INFO used_memory_peak to match peak memory. This generated some confusion among users even if it was not an actual bug. * [FIX] Fixed an critical EVALSHA script cache bug: scripts executed may not propagate to AOF / Slaves correctly under certain conditions. See issue #1549 at Github for more information. * [FIX] Fixed multiple bugs resulting into closing the link with master or slave during replication without good reasons. This will result in useless resynchronizations, or infinite loops where the replication link can't be established. * [FIX] Don't count the time needed to populate the buffers of clients waiting in MONITOR mode when populating the Slow Log entries. * [NEW] Redis-cli updated to use SCAN instead of random sampling via RANDOMKEY in order to implement --bigkeys feature. Moreover the implementation now supports pipelining and reports more information at the end of the scan. Much faster, much better. A special thank you to Michael Grunder for this improvement. * [NEW] redis-cli now supports a new --intrinsic-latency mode that is able to meter the latency of a system due to kernel / hypervisor. How to use it is explained at http://redis.io/topics/latency. * [NEW] New command BITPOS: find first bit set or clear in a bitmap. * [NEW] CONFIG REWRITE calls are now logged. * [NEW] AOF write errors (like no space on device) no longer abort Redis if the fsync policy is none or every second. The database enters a read-only mode where every write is refused with an error. Normal operations are restored as soon as Redis is able to append again data to the AOF file. * [NEW] Sentinel now accepts SHUTDOWN command. >> Cluster changes * [FIX] Bind the first interface listed in the "bind" configuration directive if any, in order to perform outgoing connections. This fixes Cluster usage when an address is bound but there are multiple interfaces that may be used to connect with other nodes. * [FIX] When an "Importing" slot is closed via CLUSTER SETSLOT NODE ... increment the configEpoch in the special case it is zero. * [FIX] Current transaction is invalidated on redirection errors. * [FIX] Abort if port does not allow for a valid cluster bus port that is always at fixed +10000 offset. * [FIX] Keys extraction algorithm fixed for ZUNIONSTORE/ZINTERSTORE and SORT. * [FIX] Better failover timeout and retry times: failover should now work reliabily when node-timeout is very small (a few milliseconds). * [FIX] Don't allow SORT GET/BY options in Cluster mode. * [FIX] Clear importing/migrating state when turning from master to slave role. * [FIX] Set slot error if we receive an update for a busy slot. * [FIX] Update node configEpoch on UPDATE messages. * [NEW] Support multi-key operations as long as keys resolve to the same hash slot, and the slot is not migrating, or it is migrating but all the mentioned keys are available. * [NEW] New DEBUG command CMDKEYS available to debug / test keys identification in Redis commands. * [NEW] redis-trib: create subcommand is now able to assign spare slaves. * [NEW] redis-trib: new subcommand 'call'. Exec command in all nodes. >> Sentinel changes * [FIX] Sentinel "IDONTKNOW" error removed as it does not made sense with the new Sentinel design. This error was actually a fix for a design error in the first implementation of Sentinel. * [FIX] Sentinel: added a missing exit() call to abort after config file checks at startup. This error was introduced with an improvement in a previous 2.8 release. * [FIX] Sentinel: better nodes fail over start time desynchronization to avoid split-brain during the voting process needed to get authorization to fail over. This means the system is less likely to need to retry and will fail over faster. No changes in behavior / correctness. * [NEW] Sentinel unit tests and framework. More tests needed and units must be improved in order to have less false positives, but it is a start and features a debugging console that is useful to fix tests or to inspect bugs causing tests failures. * [NEW] New Sentinel events: +/-monitor and +set used to monitor when an instance to monitor is added or removed, or when a configuration is modified via SENTINEL SET. --[ Redis 3.0.0 Beta 1 (version 2.9.50) ] Release date: 11 Feb 2014 This is the first beta of Redis 3.0.0. The following is a list of improvements in Redis 3.0, compared to Redis 2.8. * [NEW] Redis Cluster: a distributed implementation of a subset of Redis. * [NEW] New "embedded string" object encoding resulting in less cache misses. Big speed gain under certain work loads. * [NEW] WAIT command to block waiting for a write to be transmitted to the specified number of slaves. * [NEW] MIGRATE connection caching. Much faster keys migraitons. * [NEW] MIGARTE new options COPY and REPLACE. * [NEW] CLIENT PAUSE command: stop processing client requests for a specified amount of time. Migrating from 2.8 to 3.0 ========================= Redis 3.0 is mostly a strict subset of 2.8, you should not have any problem upgrading your application from 2.8 to 3.0. However this is a list of small non-backward compatible changes introduced in the 3.0 release: * The log format was modified. The prefix of each line included the pid in the following format [1234]. Now instead it is 1234:? Where '?' is actually the role of the instance. M for master, S for slave, C if this process is a saving child (for RDB/AOF), and X for Sentinel. -------------------------------------------------------------------------------- Credits: Where not specified the implementation and design is done by Salvatore Sanfilippo. Thanks to Pivotal for making all this possible. Also many thanks to all the other contributors and the amazing community we have. See commit messages for more credits. Cheers, Salvatore