Background I/O library enhanced so that the main thread can query for the number...

[redis.git] / TODO

Redis TODO
----------

WARNING: are you a possible Redis contributor?
         Before implementing what is listed what is listed in this file
         please drop a message in the Redis google group or chat with
         antirez or pietern on irc.freenode.org #redis to check if the work
         is already in progress and if the feature is still interesting for
         us, and *how* exactly this can be implemented to have good changes
         of a merge. Otherwise it is probably wasted work! Thank you


API CHANGES
===========

* Turn commands into variadic versions when it makes sense, that is, when
  the variable number of arguments represent values, and there is no conflict
  with the return value of the command.

2.6
===

* Everything under the "SCRIPTING" section.
* Float increments (INCRBYFLOAT).
* Fix BRPOPLPUSH + vararg LPUSH semantics.
* AOF everysec fsync in background (either the aof-bg branch or something else).

CLUSTER
=======

* Implement rehashing and cluster check in redis-trib.
* Reimplement MIGRATE / RESTORE to use just in memory buffers (no disk at
  all). This will require touching a lot of the RDB stuff around, but we may
  hand with faster persistence for RDB.
* Implement the slave nodes semantics and election.
* Allow redis-trib to create a cluster-wide snapshot (using SYNC).
* Allow redis-trib to restore a cluster-wide snapshot (implement UPLOAD?).

SCRIPTING
=========

* MULTI/EXEC/...: should we do more than simply ignoring it?
* Prevent Lua from calling itself with redis("eval",...)
* SCRIPT FLUSH or alike to start a fresh interpreter?
* Check better the replication handling.
* Prevent execution of writes if random commands are used.

APPEND ONLY FILE
================

* in AOF rewirte use HMSET to rewrite small hashes instead of multiple calls
  to HSET.

OPTIMIZATIONS
=============

* Avoid COW due to incrementing the dict iterators counter.
* 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.
* Read-only mode for slaves.
* Redis big lists as linked lists of small ziplists?
  Possibly a simple heuristic that join near nodes when some node gets smaller than the low_level, and split it into two if gets bigger than high_level.

RANDOM
======

* Server should abort when getcwd() fails if there is some kind of persistence configured. Check this in the cron loop.
* Clients should be closed as far as the output buffer list is bigger than a given number of elements (configurable in redis.conf)
* Should the redis default configuration, and the default redis.conf, just bind 127.0.0.1?

KNOWN BUGS
==========

* #519: Slave may have expired keys that were never read in the master (so a DEL
  is not sent in the replication channel) but are already expired since
  a lot of time. Maybe after a given delay that is undoubltly greater than
  the replication link latency we should expire this key on the slave on
  access?