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Explained the Coherence Elastic data ram journal and flash journal manager configurations. (Doc ID 2405387.1)

Last updated on NOVEMBER 14, 2022

Applies to:

Oracle Coherence - Version 3.7.1 and later
Information in this document applies to any platform.


Oracle Coherence is an in-memory caching solution, often referred to as an in-memory data grid.  However, what do you do when core memory is still insufficient? Oracle Coherence provides a mechanism to solve this problem—it takes advantage of high-performing secondary storage such as solid state disk or SSD. Solid State or Flash Disk differ from traditional disk media in that they have no moving parts, relying on DRAM- or EEPROM-style memory to store data. As a result, SSD-based devices are incredibly fast with speeds close to or equal to traditional memory. 

Oracle Coherence can take advantage of SSD and similar devices to greatly expand the size of cache data with little or no sacrifice in speed. This feature is provided via Oracle Coherence Elastic Data, which allows SSD devices to be specified as the backing storage for a cache, thereby vastly expanding available memory. Using Elastic Data, memory can "spill over" to an SSD device as required, increasing memory size, and returning back to core memory when usage drops. In this way, the size of the core memory becomes elastic.

This document covers the basic architecture of Elastic data, how to configure Elastic Data–aware caches, and how to control Elastic data behavior using operational configuration overrides. 

Questions and Answers

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In this Document
Questions and Answers
 Configuring a RAM Journal Backing Map
 Configuring a Flash Journal Backing Map

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