Redis TODO and Roadmap
+----------------------
-VERSION 1.4 TODO (Hash type)
-============================
-
-* BRPOPLPUSH
-* RPOPLPUSH should notify blocking POP operations
-* List ops like L/RPUSH L/RPOP should return the new list length.
-* Save dataset / fsync() on SIGTERM
-* MULTI/EXEC should support the "EXEC FSYNC" form
-* Synchronous Virtual Memory
-* BLPOP & C. tests (write a non blocking Tcl client as first step)
-
-Virtual Memory sub-TODO:
-* Check if the page selection algorithm is working well.
-* Fix support for large files
-* Divide swappability of objects by refcount
-* While loading DB from snapshot or AOF, swap objects as needed if maxmemory
- is reached, calling swapOneObject().
-* vm-swap-file <filename>. The swap file should go where the user wants, and if it's already there and of the right size we can avoid to create it again.
-
-VERSION 1.6 TODO (Virtual memory)
-=================================
-
-* Asynchronous Virtual Memory
-* Hashes (HSET, HGET, HEXISTS, HLEN, ...).
-
-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)
+VERSION 2.2 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.
+* Support for syslog(3).
+* Implement an UDP interface for low-latency operations.
+* Use the same pointer of db->dict in db->expire hash table for keys.
+ 1) Set the keyptr hash table type key destructor to NULL.
+ 2) Don't copy the key in setExpire(), but instead lookup the same key
+ in the dict hash table, and use it.
+ 3) Make sure (and add comments about this) that when a key is deleted or
+ an expire is touched, the order is: delete the expire, delete the key.
+ 4) Make sure the SETEX command works well in all the cases. Add tests.
-VERSION 2.2 TODO (Optimizations and latency)
-============================================
+VERSION 2.x TODO
+================
-* 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.
+* BRPOPLPUSH
+* Save dataset / fsync() on SIGTERM
+* Change the implementation of ZCOUNT to use the augmented skiplist in order to be much faster.
+
+Virtual Memory optimizations:
+* Use multiple open FDs against the VM file, one for thread.
+* 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.
+* Implement LEN, PEEK, POKE, SETBIT, GETBIT
OTHER IMPORTANT THINGS THAT WILL BE ADDED BUT I'M NOT SURE WHEN
===============================================================
* 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)
-* ZRANK: http://docs.google.com/viewer?a=v&q=cache:tCQaP3ZeN4YJ:courses.csail.mit.edu/6.046/spring04/handouts/ps5-sol.pdf+skip+list+rank+operation+augmented&hl=en&pid=bl&srcid=ADGEEShXuNjTcZyXw_1cq9OaWpSXy3PprjXqVzmM-LE0ETFznLyrDXJKQ_mBPNT10R8ErkoiXD9JbMw_FaoHmOA4yoGVrA7tZWiy393JwfCwuewuP93sjbkzZ_gnEp83jYhPYjThaIzw&sig=AHIEtbRF0GkYCdYRFtTJBE69senXZwFY0w
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
* 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.
+* PING the master from time to time to check if it's gone.
THE "MAYBE" TODO LIST: things that may or may not get implemented
=================================================================
* Pattern-matching replication.
* 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.
+
+KNOWN BUGS
+==========
+
+* 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.
projects / redis.git / blobdiff