KV-Engine

Welcome to the Couchbase KV-Engine project.

This started as Couchbase's fork of the upstream memcached project, but has substantially evolved since then. It contains the bulk of the code for the Key/Value service of Couchbase Server.

Repository Layout

Areas of interest in the repository:

• include/ - Public header files.
• daemon/ - Source for the main daemon process (also known as the server). This is where main() lives.
• engines/ - Source for the different engines (aka bucket types) supported. Includes:
  • ep - Eventually Persistent Engine. Powers the Couchbase and Ephemeral bucket types.
  • ewouldblock engine - Test engine which interposes a real engine and can perform various types of error-injection.
• tests/ - Test cases.
• licenses/ - The various licenses in use

Building

KV-Engine has a number of external dependancies, as such it should be built via the Couchbase top-level Makefile.

Documentation

Architecture

• KV-Engine Architecture
• CBSASL
• Connections
• Audit
• Event Tracing / Phosphor
• Document attributes
• Environment variables
• Role Based Access Control (RBAC)
• SSL Client Certificate
• DCP
• Memcached configuration file
• Network interfaces
• HiFi MFU Eviction Policy
• Throttling

Protocols

• Memcached Binary Protocol
  • SASL
  • Duplex mode
  • External Authentication Provider
  • DCP
  • Subdoc

Policies / Guidelines

• Coding Standards
• Error Handling Best Practices

Tools

• Analyze jemalloc memory statistics

Related Projects

While the bulk of code making up KV-Engine is in this repo, there are a number of other repositories which contribute to the final program:

• couchbase/couchstore - Couchbase storage file library.
• couchbase/phosphor - Phosphor: high performance event tracing framework.
• couchbase/platform - Platform abstraction layer.
• couchbase/subjson - subjson - quickly manipulate JSON subfields.