-BEFORE REDIS 1.0.0-rc1
-
- * Add number of keys for every DB in INFO
- * maxmemory support
- * Resize the expires and Sets hash tables if needed as well? For Sets the right moment to check for this is probably in SREM
- * What happens if the saving child gets killed or segfaults instead of ending normally? Handle this.
- * check 'server.dirty' everywere. Make it proprotional to the number of objects modified.
- * Shutdown must kill other background savings before to start saving. Otherwise the DB can get replaced by the child that rename(2) after the parent for some reason. Child should trap the signal and remove the temp file name.
- * Objects sharing configuration, add the directive `objectsharingpool <size>`
- * Make sure to convert all the fstat() calls to 64bit versions.
- * Cover most of the source code with test-redis.tcl
-
-AFTER 1.0 stable release
-
- * Consistent hashing implemented in all the client libraries having an user base
- * SORT: Don't copy the list into a vector when BY argument is constant.
- * SORT ... STORE keyname. Instead to return the SORTed data set it into key.
- * Profiling and optimization in order to limit the CPU usage at minimum
- * 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.
- * Elapsed time in logs for SAVE when saving is going to take more than 2 seconds
- * LOCK / TRYLOCK / UNLOCK as described many times in the google group
- * Replication automated tests
- * some kind of sorted type, example:
- ZADD mykey foo 100
- ZADD mykey bar 50
- ZRANGE mykey 0 1 => bar foo
- This is able to take elements sorted because a binary tree is used to store
- the elements by 'score', with the actual value being the key. On the other
- side the type also takes an hash table with key->score mapping, so that when
- there is an update we lookup the current score and can traverse the tree.
- * BITMAP type
- * LRANGE 4 0 should return the same elements as LRANGE 0 4 but in reverse order
-
-FUTURE HINTS
-
-- In memory compression: if in-memory values compression will be implemented, make sure to implement this so that addReply() is able to handle compressed objects, just creating an uncompressed version on the fly and adding this to the output queue instead of the original one. When insetad we need to look at the object string value (SORT BY for example), call a function that will turn the object into an uncompresed one.
+Redis TODO and Roadmap
+
+VERSION 2.0 TODO
+================
+
+* BRPOPLPUSH
+* 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?
+* BLPOP & C. tests (write a non blocking Tcl client as first step)
+* ZCOUNT sortedset min max
+* 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
+* 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).
+
+* 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, SUBSTR, 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.
+
+Interesting readings about this:
+
+ - http://ayende.com/Blog/archive/2009/04/06/designing-rhino-dht-a-fault-tolerant-dynamically-distributed-hash.aspx
+
+VERSION 2.4 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.
+
+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).
+* Specially encoded sets of integers (this includes a big refactoring providing an higher level layer for Sets manipulation)
+
+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
+* 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.
+
+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 ;)
+
+* 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.
+* 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.
projects / redis.git / blobdiff