HTTP API for Free? Check out CouchDB

HTTP API for Free? Check out CouchDB Nils Breunese, VPRO N.Breunese@vpro.nl @breun

HTTP API HTTP is simple Every OS and programming language supports HTTP Lots of tooling available: proxying, caching, monitoring, etc. “Cool! So, how do I get one for my data?”

Relax!

Apache CouchDB Document-oriented database Built-in HTTP server Map/Reduce Replication Written in Erlang, fast and reliable

CAP Theorem Consistency: all nodes see the same data at the same time Availability: node failures do not prevent survivors from continuing to operate Partition tolerance: the system continues to operate despite arbitrary message loss Choose any two; you can’t have all three

Eventual Consistency Consistency Partition Availability tolerance

CouchDB at VPRO - Broadcasts - Trailers - Clips Supplier 1 - Trailers - Etc. Media Supplier 2 Service Websites Etc. CouchDB ActiveMQ CouchDB Apps Twitter Publisher Mashup Etc. Flickr Harvester Etc. - Articles - Photos - Tweets - News - Etc.

Document

What’s a Document? JSON Schemaless Attachments

HTTP Document API Create POST /db Read GET /db/id Update PUT /db/id Delete DELETE /db/id (Also: HTTP Bulk Document API)

Views {“_id”: “myid1”, keywords: [“foo”,”bar”], title: “title1”, ...} {“_id”: “myid2”, keywords: [“foo”,”baz”], title: “title2”, ...} docs function(doc) { {key: “foo”, value: “title1”} doc.keywords.forEach(function(keyword) { {key: “foo”, value: “title2”} emit(keyword, doc.title); {key: “bar”, value: “title1”} }); {key: “baz”, value: “title2”} } map _count reduce {key: “foo”, value: 2} {key: “bar”, value: 1} {key: “baz”, value: 1}

Performance Append-only B-trees (crash proof) Views are pre-calculated indexes Incremental map/reduce Trade disk space for performance Very low RAM usage

HTTP View API /{db}/_design/{ddoc}/_view/{view_name} Query parameters: key=”foo” startkey, startkey_docid, endkey, endkey_docid limit, descending, skip, group, group_level, reduce /db/_design/unconf/_view/by_keyword?key=”foo”

Using the API Client-side: AJAX from browser (JSONP support in CouchDB) Invisible for search engines Server-side You can use a library like jcouchdb Indexable!

Formatting Data Show function: transform a document into... SVG, HTML, MP3, etc. List function: transform a view result RSS, etc.

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Media Archive

Mashups

Public API Rewrite handlers for prettier URL’s API keys, monitoring, etc.? You might need an extra layer

CouchApp Replicatable HTML/JavaScript application Without any middleware! CouchApp tool to manage design documents

More CouchDB Website: http://couchdb.apache.org/ Book: http://guide.couchdb.org/ BigCouch: sharding GeoCouch: support for geospatial queries couchdb-lucene: full-text indexing and querying Myriad third-party libraries

VPRO Digital http://weblogs.vpro.nl/digitaal/ (Dutch)

http://weblogs.vpro.nl	83
http://www.nosqldatabases.com	36
https://infohubble.jira.com	15
http://confluence.infohubble.com	5

HTTP API for Free? Check out CouchDB

by Nils Breunese on Sep 22, 2010

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HTTP API for Free? Check out CouchDB — Presentation Transcript