Apache CouchDB @ OGLF09

These are the slides from my Ontario [GNU] Linux Fest 2009 talk on Apache CouchDB. You can download the PDF or see the Slideshare.

This is an example of a JSON document.

This is the same example as before but formated in XML.

JSON has the same basic data types as JavaScript.

RFC 2616

RFC 2616 Section 9

RFC 2616 Section 10

Now you Friend has full control of the data on his instance of CouchDB.

You Fiends can replicate his changes back to you.

This can work on large scale distribution as while.

We are calling the PUT method to our new database name.

And if everything is okay we will receive a 201 Created response and some JSON of {"ok":true}.

If we try an create a database that already exists on the system we get a 412 Precondition Failed.

We are calling the DELETE method to out database to remove the database from the CouchDB node.

And because the database exists we get back a 200 OK response.

Using the GET method...

We receive a JSON of all the documents in the Database and a 200 OK response.

Here is the JSON in pretty print.

To create a document in the database we need to use the POST method and include some data...

We then get a 201 Created response and a JSON document that contains the id and rev (reversion) of the newly created document.

We use the GET method and include the document id...

and get back a response of 200 OK and a JSON document. Note the HTTP header Etag, this is here so if you wanted to setup a proxy in front of a cluster of CouchDB nodes.

This is the same JSON document as above in pretty print.

To update a document we use the method PUT and include the current document with our appended changes.

Notice the rev has gone up by one.

couchdb-python, CouchKit, and CouchQuery.

CouchRest.

CouchBeam.

CouchDB4J.

If you are going to build your own library all you really need is your language's HTTP module (httplib, Net::HTTP, java.net.HttpUrlConnection, and net/http) and a third party JSON dumper.

Mozilla Raindrop is an exciting new messaging platform developed by the Thunderbird team. Not only does it use CouchDB as a database but also uses the built in HTTP server for the client. Using a technique called CouchApp, you can build HTML/JavaScript applications on top of your CouchDB database.

Ubuntu One is using CouchDB to store Contacts, Calendars, and bookmarks on your computer. With the release of Karmic Kola CouchDB will be installed by default on your computer.