0001 [Note: this is the Redis manifesto, for general information about
0002 installing and running Redis read the README file instead.]
0004 Redis Manifesto
0007 1 - A DSL for Abstract Data Types. Redis is a DSL (Domain Specific Language)
0008 that manipulates abstract data types and implemented as a TCP daemon.
0009 Commands manipulate a key space where keys are binary-safe strings and
0010 values are different kinds of abstract data types. Every data type
0011 represents an abstract version of a fundamental data structure. For instance
0012 Redis Lists are an abstract representation of linked lists. In Redis, the
0013 essence of a data type isn't just the kind of operations that the data types
0014 support, but also the space and time complexity of the data type and the
0015 operations performed upon it.
0017 2 - Memory storage is #1. The Redis data set, composed of defined key-value
0018 pairs, is primarily stored in the computer's memory. The amount of memory in
0019 all kinds of computers, including entry-level servers, is increasing
0020 significantly each year. Memory is fast, and allows Redis to have very
0021 predictable performance. Datasets composed of 10k or 40 millions keys will
0022 perform similarly. Complex data types like Redis Sorted Sets are easy to
0023 implement and manipulate in memory with good performance, making Redis very
0024 simple. Redis will continue to explore alternative options (where data can
0025 be optionally stored on disk, say) but the main goal of the project remains
0026 the development of an in-memory database.
0028 3 - Fundamental data structures for a fundamental API. The Redis API is a direct
0029 consequence of fundamental data structures. APIs can often be arbitrary but
0030 not an API that resembles the nature of fundamental data structures. If we
0031 ever meet intelligent life forms from another part of the universe, they'll
0032 likely know, understand and recognize the same basic data structures we have
0033 in our computer science books. Redis will avoid intermediate layers in API,
0034 so that the complexity is obvious and more complex operations can be
0035 performed as the sum of the basic operations.
0037 4 - Code is like a poem; it's not just something we write to reach some
0038 practical result. Sometimes people that are far from the Redis philosophy
0039 suggest using other code written by other authors (frequently in other
0040 languages) in order to implement something Redis currently lacks. But to us
0041 this is like if Shakespeare decided to end Enrico IV using the Paradiso from
0042 the Divina Commedia. Is using any external code a bad idea? Not at all. Like
0043 in "One Thousand and One Nights" smaller self contained stories are embedded
0044 in a bigger story, we'll be happy to use beautiful self contained libraries
0045 when needed. At the same time, when writing the Redis story we're trying to
0046 write smaller stories that will fit in to other code.
0048 5 - We're against complexity. We believe designing systems is a fight against
0049 complexity. We'll accept to fight the complexity when it's worthwhile but
0050 we'll try hard to recognize when a small feature is not worth 1000s of lines
0051 of code. Most of the time the best way to fight complexity is by not
0052 creating it at all.
0054 6 - Two levels of API. The Redis API has two levels: 1) a subset of the API fits
0055 naturally into a distributed version of Redis and 2) a more complex API that
0056 supports multi-key operations. Both are useful if used judiciously but
0057 there's no way to make the more complex multi-keys API distributed in an
0058 opaque way without violating our other principles. We don't want to provide
0059 the illusion of something that will work magically when actually it can't in
0060 all cases. Instead we'll provide commands to quickly migrate keys from one
0061 instance to another to perform multi-key operations and expose the tradeoffs
0062 to the user.
0064 7 - We optimize for joy. We believe writing code is a lot of hard work, and the
0065 only way it can be worth is by enjoying it. When there is no longer joy in
0066 writing code, the best thing to do is stop. To prevent this, we'll avoid
0067 taking paths that will make Redis less of a joy to develop.