In
computing
Computing is any goal-oriented activity requiring, benefiting from, or creating computer, computing machinery. It includes the study and experimentation of algorithmic processes, and the development of both computer hardware, hardware and softw ...
, a distributed cache is an extension of the traditional concept of
cache used in a single
locale. A distributed cache may span multiple servers so that it can grow in size and in transactional capacity. It is mainly used to store application data residing in
database
In computing, a database is an organized collection of data or a type of data store based on the use of a database management system (DBMS), the software that interacts with end users, applications, and the database itself to capture and a ...
and web
session data. The idea of distributed caching has become feasible now because
main memory
Computer data storage or digital data storage is a technology consisting of computer components and recording media that are used to retain digital data. It is a core function and fundamental component of computers.
The central processin ...
has become very cheap and
network cards have become very fast, with 1 Gbit now standard everywhere and 10 Gbit gaining traction. Also, a distributed cache works well on lower cost machines usually employed for
web server
A web server is computer software and underlying Computer hardware, hardware that accepts requests via Hypertext Transfer Protocol, HTTP (the network protocol created to distribute web content) or its secure variant HTTPS. A user agent, co ...
s as opposed to
database server
A database server is a server which uses a database application that provides database services to other computer programs or to computers, as defined by the client–server model. Database management systems (DBMSs) frequently provide database- ...
s which require expensive hardware.
An emerging internet architecture known as
Information-centric networking (ICN) is one of the best examples of a distributed cache network. The ICN is a network level solution hence the existing distributed network cache management schemes are not well suited for ICN. In the
supercomputer
A supercomputer is a type of computer with a high level of performance as compared to a general-purpose computer. The performance of a supercomputer is commonly measured in floating-point operations per second (FLOPS) instead of million instruc ...
environment, distributed cache is typically implemented in the form of
burst buffer
In the high-performance computing environment, burst buffer is a fast intermediate storage layer positioned between the front-end computing processes and the back-end storage systems. It bridges the performance gap between the processing speed o ...
.
In distributed caching, each cache key is assigned to a specific
shard (a.k.a. partition). There are different sharding strategies:
* Modulus sharding
* Range-based sharding
*
Consistent hashing evenly distributes cache keys across shards, even if some of the shards crash or become unavailable.
Examples
*
Aerospike
*
Apache Ignite
*
Couchbase
*
Ehcache
*
GigaSpaces
*
Hazelcast
In computing, Hazelcast is a unified real-time data platform implemented in Java that combines a fast data store with stream processing. It is also the name of the company that develops the product. The Hazelcast company is funded by venture ca ...
*
Infinispan
*
Memcached
Memcached (pronounced variously /mɛmkæʃˈdiː/ ''mem-cash-dee'' or /ˈmɛmkæʃt/ ''mem-cashed'') is a general-purpose distributed memory-caching system. It is often used to speed up dynamic database-driven websites by caching data and object ...
*
Oracle Coherence
*
Riak
*
Redis
Redis (; Remote Dictionary Server) is an in-memory key–value database, used as a distributed cache and message broker, with optional durability. Because it holds all data in memory and because of its design, Redis offers low- latency reads ...
*
Tarantool
*
Velocity
Velocity is a measurement of speed in a certain direction of motion. It is a fundamental concept in kinematics, the branch of classical mechanics that describes the motion of physical objects. Velocity is a vector (geometry), vector Physical q ...
/AppFabric
See also
*
Cache algorithms
*
Cache coherence
In computer architecture, cache coherence is the uniformity of shared resource data that is stored in multiple local caches. In a cache coherent system, if multiple clients have a cached copy of the same region of a shared memory resource, all ...
*
Cache-oblivious algorithm
In computing, a cache-oblivious algorithm (or cache-transcendent algorithm) is an algorithm designed to take advantage of a processor cache without having the size of the cache (or the length of the cache lines, etc.) as an explicit parameter. An ...
*
Cache stampede
A cache stampede is a type of cascading failure that can occur when massively parallel computing systems with caching mechanisms come under a very high load. This behaviour is sometimes also called dog-piling.
To understand how cache stampedes o ...
*
Cache language model
*
Database cache
In computing, a database is an organized collection of data or a type of data store based on the use of a database management system (DBMS), the software that interacts with end users, applications, and the database itself to capture and analy ...
*
Cache manifest in HTML5
References
{{Reflist
Cache (computing)
Distributed computing