X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/e3f46030fcfd0ffd916d473b16d0ed07e138fefb..7fc98533392f455974d546c88bd4d41c85e6fe6d:/TODO diff --git a/TODO b/TODO index f9fa8f2a..d02e260c 100644 --- a/TODO +++ b/TODO @@ -1,52 +1,27 @@ Redis TODO and Roadmap +---------------------- -VERSION 2.0 TODO +VERSION 2.2 TODO (Optimizations and latency) +============================================ + +* Lower the CPU usage. +* Lower the RAM usage everywhere possible. +* 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 -* 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. +* Change the implementation of ZCOUNT to use the augmented skiplist in order to be much faster. -Virtual Memory sub-TODO: -* Check if the page selection algorithm is working well -* Divide swappability of objects by refcount +Virtual Memory optimizations: * 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 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, 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. +* 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 =============================================================== @@ -66,6 +41,7 @@ SMALL ONES: * 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 =================================================================