Voldemort is a
distributed data store that was designed as a
key-value store used by
LinkedIn
LinkedIn () is an American business and employment-oriented online service that operates via websites and mobile apps. Launched on May 5, 2003, the platform is primarily used for professional networking and career development, and allows job se ...
for highly-scalable storage.
It is named after the fictional ''
Harry Potter
''Harry Potter'' is a series of seven fantasy novels written by British author J. K. Rowling. The novels chronicle the lives of a young wizard, Harry Potter, and his friends Hermione Granger and Ron Weasley, all of whom are students at ...
'' villain
Lord Voldemort
Lord Voldemort ( , in the films) is a sobriquet for Tom Marvolo Riddle, a character and the main antagonist in J. K. Rowling's series of '' Harry Potter'' novels. The character first appeared in '' Harry Potter and the Philosopher's S ...
.
Overview
Voldemort does not try to satisfy arbitrary relations and the
ACID
In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a se ...
properties, but rather is a big, distributed, persistent hash table.
A 2012 study comparing systems for storing
application performance management
In the fields of information technology and systems management, application performance management (APM) is the monitoring and management of the performance and availability of software applications. APM strives to detect and diagnose complex app ...
data reported that Voldemort,
Apache Cassandra, and
HBase all offered linear scalability in most cases, with Voldemort having the lowest latency and Cassandra having the highest throughput.
In the parlance of Eric Brewer's
CAP theorem
In theoretical computer science, the CAP theorem, also named Brewer's theorem after computer scientist Eric Brewer, states that any distributed data store can provide only two of the following three guarantees:Seth Gilbert and Nancy Lynch"Brewe ...
, Voldemort is an AP type system.
Voldemort's creator and primary corporate contributor, LinkedIn, has migrated all of their systems off of Voldemort as of approximately August 2018, with no replacement sponsor .
Properties
Voldemort uses in-memory caching to eliminate a separate caching tier. It has a storage layer that is possible to emulate. Voldemort reads and writes
scale horizontally. The API decides data replication and placement and accommodates a wide range of application-specific strategies.
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The Voldemort distributed data store supports pluggable placement strategies for distribution across data centers. Data is automatically replicated across servers. Data is partitioned meaning a single server contains only a portion of the total data. Each data node is independent to avoid central point of failure. Pluggable serialization allows rich keys and values including lists and tuples with named fields, as well as the integration with common serialisation frameworks such as Avro
AVRO, short for Algemene Vereniging Radio Omroep ("General Association of Radio Broadcasting"), was a Dutch public broadcasting association operating within the framework of the Nederlandse Publieke Omroep system. It was the first public broa ...
, Java Serialization, Protocol Buffers
Protocol Buffers (Protobuf) is a free and open-source cross-platform data format used to serialize structured data. It is useful in developing programs to communicate with each other over a network or for storing data. The method involves an i ...
, and Thrift. Server failures are handled transparently. Data items are versioned, which maximizes data integrity.
See also
* Distributed data store
* NoSQL
A NoSQL (originally referring to "non- SQL" or "non-relational") database provides a mechanism for storage and retrieval of data that is modeled in means other than the tabular relations used in relational databases. Such databases have existed ...
* Riak
* Redis
Redis (; Remote Dictionary Server) is an in-memory data structure store, used as a distributed, in-memory key–value database, cache and message broker, with optional durability. Redis supports different kinds of abstract data structures, s ...
References
External links
Project Voldemort - A distributed database
Project Voldemort Real Time Discussions
{{Microsoft FOSS
Distributed data stores
LinkedIn software
NoSQL
Microsoft free software
Software using the Apache license
2009 software