Geode

Apache Geode is an open-source, in-memory distributed data grid that scales out horizontally across nodes.

History

Originally released commercially in 2002 under GemStone Systems as Gemfire, it was first used in Wall Street trading platforms. In 2010, GemStone Systems was acquired by VMWare and by 2013, Pivotal had spun out of VMWare and took Gemfire with it. Pivotal then proceeded to submit Gemfire to the Apache Incubator in 2015 under the name Geode, and was graduated to a top-level project in 2016. Now, Geode is used in many businesses with high-scale applications.

Storage Architecture

In-Memory

Geode is a data grid, meaning it stores caches of the database, and does so in- memory.

Isolation Levels

Read Uncommitted Repeatable Read

Geode supports repeatable reads, but its default allows for dirty reads.

Concurrency Control

Timestamp Ordering

Any modifications to caches are replicated and checked for consistency before acknowledging success. If there are any concurrent modifications, then changes are made according to time stamp.

Indexes

Hash Table

Keys are hashed using fixed number of buckets.