= Chronicle Map

Chronicle Map is a super-fast, in-memory, key-value store, designed for low-latency, and/or multi-process applications such as trading and financial market applications.


The size of a Chronicle Map is not limited by memory (RAM), but rather by the available disk capacity.

image::docs\images\CM_Overview.jpg[]

== Prerequisites

To run Chronicle Map, please ensure you have first installed:

* Java (1.8.0_91 or later)
* Apache Maven (3.2.3 or later)

=== Use cases
Chronicle Map is used in production around the
world for:

• **real-time trading systems**. Chronicle Map
provides in-memory access speeds, and supports
ultra-low garbage collection. Chronicle Map can support the most demanding of applications.
• **highly concurrent systems**. Chronicle Map
supports multiple readers and writers,
distributed across multiple machines.

=== Why use Chronicle Map?
Chronicle Map is:

• **fast**. Millions of operations per second, with
low and stable microsecond latencies.
• **reliable**. Chronicle Software have a “chaos
monkey” test which verifies Chronicle Map
multi-master replication in the face of node
and network failures.
• **in production** at banks and hedge funds,
globally.
• **built using lessons learnt** from real-world
experience solving real-world problems.
• **open source** (standard version), and in use at
hundreds of sites around the world.

=== Our offering
Chronicle Software provides full support for
Chronicle Map, consulting to help you make
best use of the product, and can also deliver
projects using a mix of our resources and
your own.

=== Replication Environment Example
The following diagram shows an example of Chronicle Map replication over three servers (or sites).

image::docs\images\Configure_Three_Way_Replication.png[]

Replication is multi-master, lock-free, redundant, deterministic, and eventually consistent.

The writer can optionally wait for replication to occur across nodes or regions.

NOTE: See <<docs/CM_Replication.adoc#,Chronicle Map Replication>> for more information.

'''
== Documentation
The Chronicle Map documentation comprises:

.Documentation
|===
|**Document**|**Purpose**
|<<docs/CM_Features.adoc#,CM_Features>>
|Features description.
|<<docs/CM_Replication.adoc#,CM_Replication>>
|Replication explanation.
|<<docs/CM_Tutorial.adoc#,CM_Tutorial>>
|Tutorial.
|<<docs/CM_FAQs.adoc#,CM_FAQs>>
|Frequently asked questions.
|<<docs/CM_Download.adoc#,CM_Download>>
|Downloading the software.
|<<docs/CM_Updates.adoc#,CM_Updates>>
|Updates from Chronicle Map version 2.
|<<docs/CM_Compatibility_and_Versioning.adoc#,CM_Compatibility_and_Versioning>>
|Compatibility and Versioning description.
|===

Linked documentation is contained in the `docs` folder.