X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/9651a78787b922916bd390c70e9a71702939fe34..7fc98533392f455974d546c88bd4d41c85e6fe6d:/TODO?ds=sidebyside diff --git a/TODO b/TODO index f904821a..d02e260c 100644 --- a/TODO +++ b/TODO @@ -1,44 +1,27 @@ Redis TODO and Roadmap +---------------------- -VERSION 1.4 TODO (Hash type) -============================ - -* 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) - -Virtual Memory sub-TODO: -* Check if the page selection algorithm is working well -* Divide swappability of objects by refcount -* 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 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 < N keys. - -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) +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. +* Specially encoded Sets (like Hashes). +* Implement an UDP interface for low-latency operations. +* What about a special coding that is about storing the "rdb" serialized format instead of the actual value? This can be used when we have LRU in order to super-compress data into memory, for data not accessed frequetly. It's a VM-alike strategy but fully in memory, may reduce the space to hold some dataset in an impressive way. Trivial to implement. +* Another idea: LRU does not need to be super precise right? Maybe it's a good idea to just put into the skiplist implementing the LRU just the pointer to the key without evne incr/decr business, nor the need to remove the pointer when the key is deleted. There is to think more about that. + +VERSION 2.x TODO +================ + +* 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 =============================================================== @@ -48,14 +31,17 @@ 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) -* 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 =================================================================