redis/00-RELEASENOTES

Redis 3.0 release notes
=======================

WARNING: Redis 3.0 is currently a BETA not suitable for production environments.

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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.
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--[ 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

* [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

* [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

* [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.

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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