* #12996 `INFO`: `allocator_muzzy` - memory returned to the OS but still shows as RSS until the OS reclaims it
* #13108 `INFO`: `evicted_scripts` - number of evicted eval scripts. Users can check it to see if they are abusing EVAL
* #12996 `MEMORY STATS`: `allocator.muzzy` - memory returned to the OS but still shows as RSS until the OS reclaims it
* #12913 `INFO MEMORY` `mem_overhead_db_hashtable_rehashing` - memory resharding overhead (only the memory that will be released soon)
* #12913 `MEMORY STATS': `overhead.db.hashtable.lut` - total overhead of dictionary buckets in databases
* #12913 `MEMORY STATS': `overhead.db.hashtable.rehashing` - temporary memory overhead of database dictionaries currently being rehashed
* #12913 `MEMORY STATS': `db.dict.rehashing.count` - number of top level dictionaries currently being rehashed
* #12966 `CLIENT LIST`: `watch` - number of keys each client is currently watching
Modules API
===========
* #12985 New API calls: `RM_TryCalloc` and `RM_TryRealloc` - allow modules to handle memory allocation failures gracefully
* #13069 New API call: `RM_ClusterKeySlot` - which slot a key will hash to
* #13069 New API call: `RM_ClusterCanonicalKeyNameInSlot` - get a consistent key that will map to a slot
* #12486 New API call: `RM_AddACLCategory` - allow modules to declare new ACL categories
Configuration parameters
========================
* #12178 New configuration parameters: `max-new-connections-per-cycle` and `max-new-tls-connections-per-cycle` to limit the number of new client connections per event-loop cycle
* #7351 Rename some CPU configuration parameters for style alignment. Added alias to the old names to avoid breaking change
CLI tools
=========
* #10609 redis-cli: new `-t <timeout>` argument: specify server connection timeout in seconds
* #11315 redis-cli: new `-4` and `-6` flags to prefer IPV4 or IPV6 on DNS lookup
* #12862 redis-cli: allows pressing up arrow to return any command (including sensitive commands which are still not persisted)
* #12543 redis-cli: add reverse history search (like Ctrl+R in terminals)
* #12826 redis-cli: add `--keystats` and `--keystats-samples` to combines `--memkeys` and `--bigkeys` with additional distribution data
* #12735 redis-cli: fix: `--bigkeys` and `--memkeys` now work on cluster replicas
* #9411 redis-benchmark: add support for binary strings
* #12986 redis-benchmark: fix: pick random slot for a node to distribute operation across slots