[redis.git] / TODO

Redis TODO and Roadmap

VERSION 1.2 TODO (Zsets, Integer encoding, Append only journal)
===============================================================

Most of the features already implemented for this release. The following is a list of the missing things in order to release the first beta tar.gz:

* When Redis runs as slave make sure to set the fake client it uses to talk to the master as c->authenticated = 1 to avoid problems with slaves with requirepassword set.
* Document BGREWRITEAOF.

VERSION 1.4 TODO (Hash type)
============================

* Blocking LPOP (BLPOP).
* Hashes (HSET, HGET, HEXISTS, HLEN, ...).
* List ops like L/RPUSH L/RPOP should return the new list length.

VERSION 1.6 TODO (Virtual memory)
=================================

* Redis Virtual Memory for datasets bigger than RAM (http://groups.google.com/group/redis-db/msg/752997c7b38553cd)

VERSION 1.8 TODO (Fault tollerant sharding)
===========================================

* Redis-cluster, a fast intermediate layer (proxy) that implements consistent hashing and fault tollerant nodes handling.

Interesting readings about this:

    - http://ayende.com/Blog/archive/2009/04/06/designing-rhino-dht-a-fault-tolerant-dynamically-distributed-hash.aspx

VERSION 2.0 TODO (Optimizations and latency)
============================================

* Lower the CPU usage.
* Lower the RAM usage everywhere possible.
* Use epool and alike to rewrite ae.c for Linux and other platforms suppporting fater-than-select() mutiplexing APIs.
* Implement an UDP interface for low-latency GET/SET operations.

VERSION 2.2 TODO (Optimizations and latency)
============================================

* JSON command able to access data serialized in JSON format. For instance if I've a key foobar with a json object I can alter the "name" file using somthing like: "JSON SET foobar name Kevin". We should have GET and INCRBY as well.

OTHER IMPORTANT THINGS THAT WILL BE ADDED BUT I'M NOT SURE WHEN
===============================================================

BIG ONES:

* Specially encoded memory-saving integer sets.
* A command to export a JSON dump (there should be mostly working patch needing major reworking).

SMALL ONES:

* Give errors when incrementing a key that does not look like an integer, when providing as a sorted set score something can't be parsed as a double, and so forth.
* MSADD (n keys) (n values). See this thread in the Redis google group: http://groups.google.com/group/redis-db/browse_thread/thread/e766d84eb375cd41

SHORT/LONG TERM RANDOM TODO ITEMS
=================================

Most of this can be seen just as proposals, the fact they are in this list
it's not a guarantee they'll ever get implemented ;)

* Move dict.c from hash table to skip list, in order to avoid the blocking resize operation needed for the hash table.
* FORK command (fork()s executing the commands received by the current
  client in the new process). Hint: large SORTs can use more cores,
  copy-on-write will avoid memory problems.
* DUP command? DUP srckey dstkey, creates an exact clone of srckey value in dstkey.
* SORT: Don't copy the list into a vector when BY argument is constant.
* Write the hash table size of every db in the dump, so that Redis can resize the hash table just one time when loading a big DB.
* LOCK / TRYLOCK / UNLOCK as described many times in the google group
* Replication automated tests
* Byte Array type (BA prefixed commands): BASETBIT BAGETBIT BASETU8 U16 U32 U64 S8 S16 S32 S64, ability to atomically INCRBY all the base types. BARANGE to get a range of bytes as a bulk value, BASETRANGE to set a range of bytes.
* zmalloc() should avoid to add a private header for archs where there is some other kind of libc-specific way to get the size of a malloced block. Already done for Mac OS X.
* Read-only mode.
* Pattern-matching replication.
* Don't save empty lists / sets / zsets on disk with snapshotting.
* Remove keys when a list / set / zset reaches length of 0.

DOCUMENTATION WISHLIST
======================

* Page explaining tips to reduce memory usage.
* A Sorted sets HOWTO
Commit	Line	Data
f284d963	1	Redis TODO and Roadmap
f284d963	2
2014c437	3	VERSION 1.2 TODO (Zsets, Integer encoding, Append only journal)
c35f7d5b	4	===============================================================
	5
	6	Most of the features already implemented for this release. The following is a list of the missing things in order to release the first beta tar.gz:
f6b141c5	7
25e52257	8	* When Redis runs as slave make sure to set the fake client it uses to talk to the master as c->authenticated = 1 to avoid problems with slaves with requirepassword set.
25e52257	9	* Document BGREWRITEAOF.
23cff1a8	10
2014c437	11	VERSION 1.4 TODO (Hash type)
c35f7d5b	12	============================
23cff1a8	13
3f477979	14	* Blocking LPOP (BLPOP).
23cff1a8	15	* Hashes (HSET, HGET, HEXISTS, HLEN, ...).
09f6f702	16	* List ops like L/RPUSH L/RPOP should return the new list length.
f6b141c5	17
2014c437	18	VERSION 1.6 TODO (Virtual memory)
c35f7d5b	19	=================================
7d65b33d	20
	21	* Redis Virtual Memory for datasets bigger than RAM (http://groups.google.com/group/redis-db/msg/752997c7b38553cd)
	22
2014c437	23	VERSION 1.8 TODO (Fault tollerant sharding)
c35f7d5b	24	===========================================
7d65b33d	25
c35f7d5b	26	* Redis-cluster, a fast intermediate layer (proxy) that implements consistent hashing and fault tollerant nodes handling.
7d65b33d	27
5b2a1c29	28	Interesting readings about this:
	29
	30	- http://ayende.com/Blog/archive/2009/04/06/designing-rhino-dht-a-fault-tolerant-dynamically-distributed-hash.aspx
	31
2014c437	32	VERSION 2.0 TODO (Optimizations and latency)
c35f7d5b	33	============================================
7d65b33d	34
	35	* Lower the CPU usage.
	36	* Lower the RAM usage everywhere possible.
	37	* Use epool and alike to rewrite ae.c for Linux and other platforms suppporting fater-than-select() mutiplexing APIs.
	38	* Implement an UDP interface for low-latency GET/SET operations.
	39
2014c437	40	VERSION 2.2 TODO (Optimizations and latency)
	41	============================================
	42
	43	* JSON command able to access data serialized in JSON format. For instance if I've a key foobar with a json object I can alter the "name" file using somthing like: "JSON SET foobar name Kevin". We should have GET and INCRBY as well.
	44
3f477979	45	OTHER IMPORTANT THINGS THAT WILL BE ADDED BUT I'M NOT SURE WHEN
	46	===============================================================
	47
	48	BIG ONES:
	49
	50	* Specially encoded memory-saving integer sets.
	51	* A command to export a JSON dump (there should be mostly working patch needing major reworking).
	52
	53	SMALL ONES:
	54
	55	* Give errors when incrementing a key that does not look like an integer, when providing as a sorted set score something can't be parsed as a double, and so forth.
25e52257	56	* MSADD (n keys) (n values). See this thread in the Redis google group: http://groups.google.com/group/redis-db/browse_thread/thread/e766d84eb375cd41
3f477979	57
c35f7d5b	58	SHORT/LONG TERM RANDOM TODO ITEMS
c35f7d5b	59	=================================
f6b141c5	60
0188805d	61	Most of this can be seen just as proposals, the fact they are in this list
	62	it's not a guarantee they'll ever get implemented ;)
	63
57033301	64	* Move dict.c from hash table to skip list, in order to avoid the blocking resize operation needed for the hash table.
682ac724	65	* FORK command (fork()s executing the commands received by the current
	66	client in the new process). Hint: large SORTs can use more cores,
	67	copy-on-write will avoid memory problems.
	68	* DUP command? DUP srckey dstkey, creates an exact clone of srckey value in dstkey.
	69	* SORT: Don't copy the list into a vector when BY argument is constant.
	70	* Write the hash table size of every db in the dump, so that Redis can resize the hash table just one time when loading a big DB.
	71	* LOCK / TRYLOCK / UNLOCK as described many times in the google group
	72	* Replication automated tests
	73	* Byte Array type (BA prefixed commands): BASETBIT BAGETBIT BASETU8 U16 U32 U64 S8 S16 S32 S64, ability to atomically INCRBY all the base types. BARANGE to get a range of bytes as a bulk value, BASETRANGE to set a range of bytes.
	74	* zmalloc() should avoid to add a private header for archs where there is some other kind of libc-specific way to get the size of a malloced block. Already done for Mac OS X.
	75	* Read-only mode.
	76	* Pattern-matching replication.
3f477979	77	* Don't save empty lists / sets / zsets on disk with snapshotting.
b32627cd	78	* Remove keys when a list / set / zset reaches length of 0.
682ac724	79
	80	DOCUMENTATION WISHLIST
	81	======================
	82
	83	* Page explaining tips to reduce memory usage.
	84	* A Sorted sets HOWTO
	85