00-RELEASENOTES

   1 Redis 2.6 release notes
   2 =======================
   3
   4 ** IMPORTANT ** Check the 'Migrating from 2.4 to 2.6' section at the end of
   5                 this file for information about what changed between 2.4 and
   6                 2.6 and how this may affect your application.
   7
   8 --------------------------------------------------------------------------------
   9 Upgrade urgency levels:
  10
  11 LOW:      No need to upgrade unless there are new features you want to use.
  12 MODERATE: Program an upgrade of the server, but it's not urgent.
  13 HIGH:     There is a critical bug that may affect some part of users. Upgrade!
  14 CRITICAL: There is a critical bug affecting MOST USERS. Upgrade ASAP.
  15 --------------------------------------------------------------------------------
  16
  17 ---[ Redis 2.5.12 (2.6 Release Candidate 6) ]
  18
  19 UPGRADE URGENCY: MODERATE.
  20
  21 * [BUGFIX]   Fixed a timing attack on AUTH (Issue #560).
  22 * [BUGFIX]   Don't assume that "char" is signed.
  23 * [BUGFIX]   Check that we have connection before enabling pipe mode.
  24 * [BUGFIX]   Use the optimized version of the function to convert a double to
  25              its string representation. Compilation was disabled because of
  26              a typo in the #if statement.
  27 * [IMPROVED} REPLCONF internal command introduced, now INFO shows slaves with
  28              correct port numbers. This makes 2.5.12 Redis Sentinel compatible.
  29 * [IMPROVED] Truncate short write from the AOF for a cleaner restart. On short
  30              writes (for instance out of space) Redis will now try to remove
  31              the half-written data so that the next restart will work without
  32              the need for the "redis-check-aof" utility.
  33 * [IMPROVED] New in INFO: aof_last_bgrewrite_status
  34 * [IMPROVED] Allow Pub/Sub in contexts where other commands are blocked.
  35 * [BUGFIX]   mark fd as writable when EPOLLERR or EPOLLHUP is returned by
  36              epoll_wait.
  37
  38 ---[ Redis 2.5.11 (2.6 Release Candidate 5) ]
  39
  40 UPGRADE URGENCY: HIGH.
  41
  42 * [BUGFIX]   Fixed Hash corruption when loading an RDB file generated by
  43              previous versions of Redis that encoded hashes using
  44              a different ziplist encoding format for small integers.
  45              All the fileds that are integers in the range 0-255 may not
  46              be recognized, or duplicated un updates, causing a crash
  47              when the ziplist is converted to a real hash. (Issue #547).
  48 * [BUGFIX]   Fixed the count of memory used by output buffers in the
  49              setDeferredMultiBulkLength() function.
  50
  51 ---[ Redis 2.5.10 (2.6 Release Candidate 4) ]
  52
  53 UPGRADE URGENCY: HIGH.
  54
  55 * [BUGFIX]   Allow PREFIX to be overwritten on "make install".
  56 * [BUGFIX]   Run the test with just one client if the computer is slow.
  57 * [BUGFIX]   Event port support in our event driven libray.
  58 * [BUGFIX]   Jemalloc updated to 3.0.0. This fixes a possibly AOF rewrite issue.
  59              See https://github.com/antirez/redis/issues/504 for info.
  60 * [BUGFIX]   Fixed issue #516: ZINTERSTORE / ZUNIONSTORE with mixed sets/zsets.
  61 * [BUGFIX]   Set fd to writable when poll(2) detects POLLERR or POLLHUP event.
  62 * [BUGFIX]   Fixed RESTORE hash failure (Issue #532).
  63 * [IMPROVED] Allow an AOF rewrite buffer > 2GB (Related to issue #504).
  64 * [IMPROVED] Server cron function frequency is now configurable (REDIS_HZ).
  65 * [IMPROVED] Better, less blocking expired keys collection algorithm.
  66 * [FEATURE]  New commands: BITOP and BITCOUNT.
  67 * [FEATURE]  redis-cli --pipe for mass import.
  68
  69 What's new in Redis 2.5.9 (aka 2.6 Release Candidate 3)
  70 =======================================================
  71
  72 UPGRADE URGENCY: critical, upgrade ASAP.
  73
  74 * [BUGFIX] Fix for issue #500 (https://github.com/antirez/redis/pull/500).
  75            Redis 2.6-RC1 and RC2 may corrupt ziplist-encoded sorted sets
  76            produced by Redis 2.4.x.
  77 * [BUGFIX] Fixed several bugs in init.d script.
  78 * [BUGFIX] syncio.c functions modified for speed and correctness. On osx
  79            (and possibly other BSD-based systems) the slave would block on
  80            replication to send the SYNC command when the master was not
  81            available. This is fixed now, but was not affecting Linux installs.
  82 * Now when slave-serve-stale-data is set to yes and the master is down, instead
  83   of reporting a generic error Redis replies with -MASTERDOWN.
  84
  85 What's new in Redis 2.5.8 (aka 2.6 Release Candidate 2)
  86 =======================================================
  87
  88 UPGRADE URGENCY: high for all the users of the KEYS command, otherwise low.
  89
  90 * [BUGFIX] Fix for KEYS command: if the DB contains keys with expires the KEYS
  91            command may return the wrong output, having duplicated or missing
  92            keys. See issue #487 and #488 on github for details.
  93
  94 What's new in Redis 2.5.7 (aka 2.6 Release Candidate 1)
  95 =======================================================
  96
  97 UPGRADE URGENCY: upgrade not recommended because this is an RC release.
  98
  99 * This is the first release candidate for Redis 2.6. We are not aware of
 100   bugs, but part of this code is young and was never tested in production
 101   environments, so handle with care.
 102
 103 An overview of new features and changes in Redis 2.6.x
 104 ======================================================
 105
 106 * Server side Lua scripting, see http://redis.io/commands/eval
 107 * Virtual Memory removed (was deprecated in 2.4)
 108 * Hardcoded limits about max number of clients removed.
 109 * AOF low level semantics is generally more sane, and especially when used
 110   in slaves.
 111 * Milliseconds resolution expires, also added new commands with milliseconds
 112   precision (PEXPIRE, PTTL, ...).
 113 * Better memory usage for "small" lists, ziplists and hashes when fields or
 114   values contain small integers.
 115 * Read only slaves.
 116 * New bit opeations: BITCOUNT and BITOP commands.
 117 * Clients max output buffer soft and hard limits. You can specifiy different
 118   limits for different classes of clients (normal,pubsub,slave).
 119 * More incremental (less blocking) expired keys collection algorithm, in
 120   practical terms this means that Redis is more responsive when a very
 121   big number of keys expire about at the same time.
 122 * AOF is now able to rewrite aggregate data types using variadic commands,
 123   often producing an AOF that is faster to save, load, and is smaller in size.
 124 * Every redis.conf directive is now accepted as a command line option for the
 125   redis-server binary, with the same name and number of arguments.
 126 * Hash table seed randomization for protection against collisions attacks.
 127 * Performances improved when writing large objects to Redis.
 128 * Integrated memory test, see redis-server --test-memory.
 129 * INCRBYFLOAT and HINCRBYFLOAT commands.
 130 * New DUMP, RESTORE, MIGRATE commands (back ported from Redis Cluster to 2.6).
 131 * CRC64 checksump in RDB files.
 132 * Better MONITOR output and behavior (now commands are logged before execution).
 133 * "Software Watchdog" feature to debug latency issues.
 134 * Significant parts of the core refactored or rewritten. New internal APIs
 135   and core changes allowed to develop Redis Cluster on top of the new code,
 136   however for 2.6 all the cluster code was removed, and will be released with
 137   Redis 3.0 when it is more complete and stable.
 138 * Redis ASCII art logo added at startup.
 139 * Crash report on memory violation or failed asserts improved significantly
 140   to make debugging of hard to catch bugs simpler.
 141 * redis-benchmark improvements: ability to run selected tests,
 142   CSV output, faster, better help.
 143 * redis-cli improvements: --eval for comfortable development of Lua scripts.
 144 * SHUTDOWN now supports two optional arguments: "SAVE" and "NOSAVE".
 145 * INFO output split into sections, the command is now able to just show
 146   pecific sections.
 147 * New statistics about how many time a command was called, and how much
 148   execution time it used (INFO commandstats).
 149 * More predictable SORT behavior in edge cases.
 150 * Better support for big endian and *BSD systems.
 151 * Build system improved.
 152
 153 Migrating from 2.4 to 2.6
 154 =========================
 155
 156 Redis 2.4 is mostly a strict subset of 2.6. However there are a few things
 157 that you should be aware of:
 158
 159 * You can't use .rdb and AOF files generated with 2.6 into a 2.4 instance.
 160 * 2.4 slaves can be attached to 2.6 masters, but not the contrary, and only
 161   for the time needed to perform the version upgrade.
 162
 163 There are also a few API differences, that are unlikely to cause problems,
 164 but it is better to keep them in mind:
 165
 166 * SORT now will refuse to sort in numerical mode elements that can't be parsed
 167   as numbers.
 168 * EXPIREs now all have millisecond resolution (but this is very unlikely to
 169   break code that was not conceived exploting the previous resolution error
 170   in some way.)
 171 * INFO output is a bit different now, and contains empty lines and comments
 172   starting with '#'. All the major clients should be already fixed to work
 173   with the new INFO format.
 174 * Slaves are only read-only by default (but you can change this easily
 175   setting the "slave-read-only" configuration option to "no" editing your
 176   redis.conf or using CONFIG SET.
 177
 178 The following INFO fields were renamed for consistency:
 179
 180      changes_since_last_save -> rdb_changes_since_last_save
 181      bgsave_in_progress -> rdb_bgsave_in_progress
 182      last_save_time -> rdb_last_save_time
 183      last_bgsave_status -> rdb_last_bgsave_status
 184      bgrewriteaof_in_progress -> aof_rewrite_in_progress
 185      bgrewriteaof_scheduled -> aof_rewrite_scheduled
 186
 187 The following redis.conf and CONFIG GET / SET parameters changed:
 188
 189     * hash-max-zipmap-entries, now replaced by hash-max-ziplist-entries
 190     * hash-max-zipmap-value, now replaced by hash-max-ziplist-value
 191     * glueoutputbuf option was now completely removed (was deprecated)
 192
 193 --------------------------------------------------------------------------------
 194
 195 Credits: Where not specified the implementation and design are done by
 196 Salvatore Sanfilippo and Pieter Noordhuis. Thanks to VMware for making all
 197 this possible. Also many thanks to all the other contributors and the amazing
 198 community we have.
 199
 200 See commit messages for more credits.
 201
 202 Cheers,
 203 Salvatore