Gizzard is an open source

sharding A database shard, or simply a shard, is a horizontal partition of data in a database or search engine. Each shard is held on a separate database server instance, to spread load. Some data within a database remains present in all shards, but so ...

framework to create custom

fault-tolerant Fault tolerance is the property that enables a system to continue operating properly in the event of the failure of one or more faults within some of its components. If its operating quality decreases at all, the decrease is proportional to the ...

, distributed

databases In computing, a database is an organized collection of data stored and accessed electronically. Small databases can be stored on a file system, while large databases are hosted on computer clusters or cloud storage. The design of databases spa ...

. It was initially used by

Twitter Twitter is an online social media and social networking service owned and operated by American company Twitter, Inc., on which users post and interact with 280-character-long messages known as "tweets". Registered users can post, like, and ...

and emerged from a wide variety of data storage problems. Gizzard operates as a

middleware Middleware is a type of computer software that provides services to software applications beyond those available from the operating system. It can be described as "software glue". Middleware makes it easier for software developers to implement c ...

networking service that runs on the Java Virtual Machine. It manages partitioning data across arbitrary backend datastores, that allows it to be accessed efficiently. The partitioning rules are stored in a forwarding table that maps key ranges to partitions. Each partition manages its own replication through a declarative replication

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

. Gizzard handles both physical and logical shards. Physical shards point to a physical database backend whereas logical shards are trees of other shards. In addition Gizzard also supports migrations and gracefully handles failures. The system is made eventually consistent by requiring that all write operations are

idempotent Idempotence (, ) is the property of certain operations in mathematics and computer science whereby they can be applied multiple times without changing the result beyond the initial application. The concept of idempotence arises in a number of pl ...

and

commutative In mathematics, a binary operation is commutative if changing the order of the operands does not change the result. It is a fundamental property of many binary operations, and many mathematical proofs depend on it. Most familiar as the name of ...

. As operations fail they are retried at a later time. Gizzard is available at

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and licensed under the Apache License 2.0.

References

External links

Project Website
Data synchronization Structured storage Free database management systems Data partitioning Java platform Free software programmed in Scala {{database-software-stub

See also

References

External links