Redis 6.0.1 于 2020 年 5 月 2 日正式发布了，如 Redis 作者 antirez 所说，这是迄今为止最“企业”化的版本，也是有史以来改动最大的一个 Redis 版本，同时也是参与开发人数最多的一个版本。
所以在使用此版本之前，建议各位开发者先进行深入的测试再考虑投产，毕竟生产坏境无小事。好了，回到本文的重点，接下来我们来重点看下 Redis 6.0.1 给我们带来了那些新功能。
Redis新功能介绍
Redis 6 的更新日志，主要包含以下五部分的内容：
- Redis 6.0-RC1 版新功能介绍；
- Redis 6.0-RC2 版新功能介绍；
- Redis 6.0-RC3 版新功能介绍；
- Redis 6.0-RC4 版新功能介绍；
- Redis 6.0.0 GA 版新功能介绍。
除了以上这些版本的更新日志外，还有 6.0.1 正式版的更新日志，不过这个正式版的发布时间只比 Redis 6.0.0 GA 晚了两天，因此只修复了一些 bug，所以我们只需要看以上五个日志即可。
1.Redis 6.0-rc1 更新日志
官方更新日志如下：
Redis 6 improves Redis in a number of key areas and is one of the largest Redis releases in the history of the project, so here we'll list only the biggest features in this release:
- The modules system now has a number of new APIs that allow module authors to make things otherwise not possible in the past. It is possible to store arbitrary module private data in RDB files, to hook on different server events, capture and rewrite commands executions, block clients on keys, and so forth.
- The Redis active expire cycle was rewritten for much faster eviction of keys that are already expired. Now the effort is tunable.
- Redis now supports SSL on all channels.
- ACL support, you can define users that can run only certain commands and/or can only access only certain keys patterns.
- Redis now supports a new protocol called RESP3, which returns more semantical replies: new clients using this protocol can understand just from the reply what type to return to the calling program.
- There is server-side support for client-side caching of key values. This feature is still experimental and will get more changes during the next release candidates, but you can already test it and read about it here: https://redis.io/topics/client-side-caching
- Redis can now optionally use threads to handle I/O, allowing to serve 2 times as much operations per second in a single instance when pipelining cannot be used.
- Diskless replication is now supported even on replicas: a replica is now able, under certain conditions the user can configure, to load the RDB in the first synchronization directly from the socket to the memory.
- Redis-benchmark now supports a Redis Cluster mode.
- SRANDMEMBER and similar commands have a better distribution.
- Redis-cli improvements.
- Systemd support rewritten.
- A Redis Cluster proxy was released here: https://github.com/artix75/redis-cluster-proxy
- A Disque module for Redis was released here: https://github.com/antirez/disque-module
此版本新增的内容最大，如下列表所示：
- 众多新模块（modules）API
- 更好的过期循环（expire cycle）
- SSL
- ACLs 权限控制
- RESP3 协议
- 客户端缓存（Client side caching）
- 多线程 IO（Threaded I/O）
- 无盘复制副本（Diskless replication on replicas）
- Redis-benchmark 的集群支持和 redis-cli 优化
- 重写 Systemd 支持（Systemd support rewrite）
- Redis 集群代理与 Redis 6 一同发布（但在不同的 repo）
- Disque 模块与 Redis 6 一同发布
2.Redis 6.0-rc2 更新日志
Hi Redis users, Redis 6 is approaching and will be released 30th of April. New release candidates will be released at the end of March, then another one mid April, to finally reach the GA at the end of April.
Redis 6 RC2 brings many fixes and new things, especially in the area of client side caching. This is the list of big changes in this release. As usually you can find the full list of commits at the end:
New features and improvements:
- ACL LOG: log denied commands, keys accesses and authentications.
- Client side caching redesigned. Now we use keys not caching slots.
- Client side caching: Broadcasting mode implemented.
- Client side caching: OPTIN/OPTOUT modes implemented.
- Remove RDB files used for replication in persistence-less instances (option).
Fixes (only selected ones, see commits for all the fixes):
- Different fixes to streams in edge cases.
- Fix duplicated CLIENT SETNAME reply because of RESP3 changes.
- Fix crash due to new active expire division by zero.
- Avoid sentinel changes promoted_slave to be its own replica.
- Fix bug on KEYS command where pattern starts with * followed by \x00.
- Threaded I/O: now the main thread is used as well to do I/O.
- Many fixes to modules APIs, and more to come in the next RCs.
- ld2string should fail if string contains \0 in the middle.
- Make the Redis test more reliable.
- Fix SPOP returning nil (see #4709). WARNING: API change.
Redis 6 RC2 带来了许多修复和新功能，尤其是客户端的缓存功能，此版本的重大更改如下列表。
- ACL LOG：记录拒绝的命令，密钥访问和身份验证。
- 重新设计了客户端缓存。现在，我们使用密钥而不是缓存插槽。
- 客户端缓存：已实现广播模式。
- 客户端缓存：已实现 OPTIN/OPTOUT 模式。
- 删除用于在非持久性实例中进行复制的 RDB 文件（可选）。
- 修复程序（仅选定的修复程序，请参阅所有修复程序的提交）：
- 在边缘情况下对流的不同修复。
- 修正由于 RESP3 更改而导致重复的 CLIENT SETNAME 答复。
- 修正因新的有效到期除以零而导致的崩溃。
- 避免将哨兵更改提升为自己的副本。
- 修复了 KEYS 命令中以 * 开头，后跟 \x00 的错误。
- 线程 I/O：现在也使用主线程来执行 I/O。
- 对模块API进行了许多修复，而在下一个RC中还会有更多修复。
- 如果字符串中间包含 \0，则 ld2string 应该失败。
- 使 Redis 测试更可靠。
