Merge remote branch 'pietern/zfixes'
[redis.git] / TODO
1 Redis TODO and Roadmap
2 ----------------------
3
4 VERSION 2.2 TODO (Optimizations and latency)
5 ============================================
6
7 * Support for syslog(3).
8 * Implement an UDP interface for low-latency operations.
9
10 VERSION 2.x TODO
11 ================
12
13 * BRPOPLPUSH
14 * Save dataset / fsync() on SIGTERM
15 * Change the implementation of ZCOUNT to use the augmented skiplist in order to be much faster.
16
17 Virtual Memory optimizations:
18 * Use multiple open FDs against the VM file, one for thread.
19 * Check what happens performance-wise if instead of creating threads again and again the same threads are reused forever. Note: this requires a way to disable this clients in the child, but waiting for empty new jobs queue can be enough.
20 * Implement LEN, PEEK, POKE, SETBIT, GETBIT
21
22 OTHER IMPORTANT THINGS THAT WILL BE ADDED BUT I'M NOT SURE WHEN
23 ===============================================================
24
25 BIG ONES:
26
27 * Specially encoded memory-saving integer sets.
28 * A command to export a JSON dump (there should be mostly working patch needing major reworking).
29 * Specially encoded sets of integers (this includes a big refactoring providing an higher level layer for Sets manipulation)
30
31 SMALL ONES:
32
33 * If sizeof(double) == sizeof(void*) we could store the double value of sorted sets directly in place of the pointer instead of allocating it in the heap.
34 * Delete on writes against expire policy should only happen after argument parsing for commands doing their own arg parsing stuff.
35 * 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.
36 * MSADD (n keys) (n values). See this thread in the Redis google group: http://groups.google.com/group/redis-db/browse_thread/thread/e766d84eb375cd41
37 * Don't save empty lists / sets / zsets on disk with snapshotting.
38 * Remove keys when a list / set / zset reaches length of 0.
39 * An option to exec a command slave-side if the master connection is lost: even cooler: if the script returns "0" the slave elects itself as master, otherwise continue trying to reconnect.
40 * PING the master from time to time to check if it's gone.
41
42 THE "MAYBE" TODO LIST: things that may or may not get implemented
43 =================================================================
44
45 Most of this can be seen just as proposals, the fact they are in this list
46 it's not a guarantee they'll ever get implemented ;)
47
48 * Move dict.c from hash table to skip list, in order to avoid the blocking resize operation needed for the hash table.
49 * FORK command (fork()s executing the commands received by the current
50 client in the new process). Hint: large SORTs can use more cores,
51 copy-on-write will avoid memory problems.
52 * DUP command? DUP srckey dstkey, creates an exact clone of srckey value in dstkey.
53 * SORT: Don't copy the list into a vector when BY argument is constant.
54 * 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.
55 * LOCK / TRYLOCK / UNLOCK as described many times in the google group
56 * Replication automated tests
57 * 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.
58 * 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.
59 * Read-only mode.
60 * Pattern-matching replication.
61 * Add an option to relax the delete-expiring-keys-on-write semantic *denying* replication and AOF when this is on? Can be handy sometimes, when using Redis for non persistent state, but can create problems. For instance should rename and move also "move" the timeouts? How does this affect other commands?
62 * Multiple BY in SORT.
63
64 KNOWN BUGS
65 ==========
66
67 * LRANGE and other commands are using 32 bit integers for ranges, and overflows are not detected. So LRANGE mylist 0 23498204823094823904823904 will have random effects.