Merge branch 'issue_191' of git://github.com/gnrfan/redis

[redis.git] / TODO

diff --git a/TODO b/TODO
index 8d4b711ed837d2fd3c85af4eb6c07c089aeb5c12..237fb649918f626836febe2e8a7c1234a7a7d43a 100644 (file)
--- a/TODO
+++ b/TODO
@@ -1,26 +1,35 @@
 Redis TODO and Roadmap
 
 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 2.0 TODO
+================

 
 

-VERSION 1.4 TODO (Hash type)
-============================
-
-* Blocking LPOP (BLPOP).
-* Hashes (HSET, HGET, HEXISTS, HLEN, ...).
+* BRPOPLPUSH

 * List ops like L/RPUSH L/RPOP should return the new list length.
 * 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)
+* Save dataset / fsync() on SIGTERM
+* MULTI/EXEC should support the "EXEC FSYNC" form?
+* BLPOP & C. tests (write a non blocking Tcl client as first step)
+* Once ZRANK is implemented, change the implementation of ZCOUNT to use the augmented skiplist in order to be much faster.
+* Write doc for ZCOUNT, and for open / closed intervals of sorted sets range operations.
+
+Virtual Memory sub-TODO:
+* Check if the page selection algorithm is working well
+* Divide swappability of objects by refcount
+* Use multiple open FDs against the VM file, one for thread.
+* it should be possible to give the vm-max-memory option in megabyte, gigabyte, ..., just using 2GB, 100MB, and so forth.
+* Try to understand what can be moved into I/O threads that currently is instead handled by the main thread. For instance swapping file table scannig to find contiguous page could be a potential candidate (but I'm not convinced it's a good idea, better to improve the algorithm, for instance double the fast forward at every step?).
+* Possibly decrRefCount() against swapped objects can be moved into I/O threads, as it's a slow operation against million elements list, and in general consumes CPU time that can be consumed by other threads (and cores).
+* EXISTS should avoid loading the object if possible without too make the code too specialized.
+* vm-min-age <seconds> option
+* Make sure objects loaded from the VM are specially encoded when possible.
+* Check what happens performance-wise if instead to create 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.
+* Sets of integers are slow to load, for a number of reasons. Fix it. (use slow_sets.rdb file for debugging). (p.s. this was now partially fixed).
+* On EXEC try to block the client until relevant keys are loaded.
+
+* Hashes (GET/SET/DEL/INCRBY/EXISTS/FIELDS/LEN/MSET/MGET). Special encoding for hashes with less than N elements.
+* Write documentation for APPEND
+* Implement LEN, PEEK, POKE, SETBIT, GETBIT
+
+VERSION 2.2 TODO (Fault tolerant sharding)

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


@@ -29,7 +38,7 @@ Interesting readings about this:
 
     - http://ayende.com/Blog/archive/2009/04/06/designing-rhino-dht-a-fault-tolerant-dynamically-distributed-hash.aspx
 
 
     - 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)
+VERSION 2.4 TODO (Optimizations and latency)

 ============================================
 
 * Lower the CPU usage.
 ============================================
 
 * Lower the CPU usage.


@@ -37,11 +46,6 @@ VERSION 2.0 TODO (Optimizations and latency)
 * 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.
 
 * 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
 ===============================================================
 
 OTHER IMPORTANT THINGS THAT WILL BE ADDED BUT I'M NOT SURE WHEN
 ===============================================================
 


@@ -49,14 +53,20 @@ BIG ONES:
 
 * Specially encoded memory-saving integer sets.
 * A command to export a JSON dump (there should be mostly working patch needing major reworking).
 
 * Specially encoded memory-saving integer sets.
 * A command to export a JSON dump (there should be mostly working patch needing major reworking).

+* Specially encoded sets of integers (this includes a big refactoring providing an higher level layer for Sets manipulation)

 
 SMALL ONES:
 
 
 SMALL ONES:
 

+* 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.
+* Delete on writes against expire policy should only happen after argument parsing for commands doing their own arg parsing stuff.

 * 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
 * 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

+* Don't save empty lists / sets / zsets on disk with snapshotting.
+* Remove keys when a list / set / zset reaches length of 0.
+* 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.

 
 

-SHORT/LONG TERM RANDOM TODO ITEMS
-=================================
+THE "MAYBE" TODO LIST: things that may or may not get implemented
+=================================================================

 
 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 ;)
 
 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 ;)


@@ -74,12 +84,5 @@ it's not a guarantee they'll ever get implemented ;)
 * 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.
 * 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
-
+* 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?
+* Multiple BY in SORT.