Post on 11-May-2015
transcript
Hello
• Chris Anderson <jchris@apache.org>
• Blog: http://jchris.mfdz.com
• Founder, Grabb.it (web analytics for music)
• Ruby on Rails veteran
• CouchDB committer
And You?
• Used CouchDB (for fun)
• Evaluating or using it (for a project)
• Interested in contributing?
• Just here for the pizza?
History
• Damien Katz <http://damienkatz.net/>
• Worked on Lotus Notes & MySQL
• Started in 2005: C++ and XML, on Windows
• 2006: Moved to Erlang, JSON, and POSIX
• 0.7.0 first release of today’s CouchDB
• Version 1.0 Planned for the end of 2008
Why CouchDB?
• Common use cases no longer fit RDBMS
• Native to web applications
• Peer-based replication for freedom
• Takes today’s scalability lessons to heart
This Talk
• How is CouchDB different (from RDBMS)?
• Example HTML/Javascript application
• Quick tour of the internals
How Is CouchDB Different?RESTful HTTP
Schemaless JSON Documents
Map/Reduce Views
Incremental Replication
How Is CouchDB Different?RESTful HTTP
Schemaless JSON Documents
Map/Reduce Views
Incremental Replication
Binary Protocol
Typed Columns & Primary Keys
Ad-hoc Queries
Replication Logs
(from SQL RDBMS)
RESTful HTTP
Built for the web
Javascript Test Suite
Standard HTTP Clients, Proxies, Load Balancers & Caches
RESTful HTTP
Built for the web
Javascript Test Suite
Standard HTTP Clients, Proxies, Load Balancers & Caches
Enterprisey
Battle Hardened
Protocol Specific Tools
Schemaless JSON Documents
Flat Namespace
Arbitrary JSON Structures
Identified By URIs
Optimistic Locking (ACID/MVCC)
Schemaless JSON Documents
Flat Namespace
Arbitrary JSON Structures
Identified By URIs
Optimistic Locking (ACID/MVCC)
Tables
Typed Columns and Key Constraints
Primary Keys
Row or Column Level Locking
Map/Reduce Views
Functional Javascript
Incremental Updates
Predefined
High-Performance Reads
Map/Reduce Views
Functional Javascript
Incremental Updates
Predefined
High-Performance Reads
SQL Statements
Independent
Ad-hoc and Complex
Indexes Computed on Writes
Incremental Replication
User Triggered
Offline Clients
Resilient & Restartable
HTTP
Incremental Replication
User Triggered
Offline Clients
Resilient & Restartable
HTTP
Continuous
Master/Slave
Critical Path
Log Based
CouchDB
HTML / Javascript
_design Documents
p2p Replication
A new way to write web applications.
Live Code!http://169.254.251.59:5984/_utils/
CouchDB Internals• couch_httpd.erl
• Request Dispatch
• Create Database
• Get Document
• Other Modules
Request Dispatch
Create Database
Get Document
Other Modules• couch_btree.erl
• The heart of the storage module (stores Erlang terms sorted by key using user specified sort funtions)
• couch_db_updater.erl
• Translates document requests into Btree actions.
• couch_query_servers.erl
• Communicates with the external (Javascript etc) view servers.
Join Us
• #couchdb on irc.freenode.net
• http://couchdb.org
• mailing lists
• links to wiki and subversion checkout
Thank You!
Any Questions?