RethinkDB: advancing the realtime web

Originally presented at OpenWest 2015.

RethinkDB is the first database that exposes an exciting new database access model -- instead of polling the database for changes, the developer can tell RethinkDB to continuously push updated query results to applications in realtime. In this talk we'll show how this model makes building modern, realtime apps dramatically easier -- you'll learn how to get a scalable realtime web app running with RethinkDB in a fraction of the time with fewer engineering resources.

Transcript

1. The open-source database for the realtime web.
2. Source: http://googledrive.blogspot.com/2014/06/newdocssheetsslides.html
4. Building realtime apps is hard It’s hard to keep track of state in realtime architectures. Realtime web app server Realtime web app server Mobile app server Message queue Database cluster Queues communicate state and messages between servers.
5. Building realtime apps is hard Polling data to keep track of updates is cumbersome. Adding new realtime functionality keeps getting harder. Routing realtime messages vs. broadcasting messages. It’s hard to keep track of state in realtime architectures.
6. What is RethinkDB? • Open source database for building realtime web apps • NoSQL database that stores schemaless JSON documents • Distributed database that is easy to scale
7. Built for realtime apps RethinkDB lets you subscribe to change notifications on database queries. r.table(‘users’).changes() # Opens a changefeed on a table Subscribe to changes on the ‘users’ table: No more polling: the database pushes changes to your app, with a live stream of updates.
8. Built for realtime apps Changefeeds let you build scalable, realtime apps. Realtime web app server Realtime web app server Mobile app server RethinkDB cluster Each server subscribes to a RethinkDB changefeed. Servers are stateless, and scale easily (just open a changefeed!)
9. Built for realtime apps Changefeeds let you build scalable, realtime apps: • Collaborative web and mobile apps • Multiplayer games • Streaming analytics apps • Realtime marketplaces • Connected devices
10. Querying RethinkDB r.table(‘users’) .pluck(‘last_name’) .distinct().count() Count unique last names with ReQL:
11. Querying RethinkDB r.table(‘users’) .pluck(‘last_name’) .distinct().count() Count unique last names with ReQL: Access a database table
12. Querying RethinkDB r.table(‘users’) .pluck(‘last_name’) .distinct().count() Count unique last names with ReQL: Isolate a document property
13. Querying RethinkDB r.table(‘users’) .pluck(‘last_name’) .distinct().count() Count unique last names with ReQL: Consolidate duplicate values
14. Querying RethinkDB r.table(‘users’) .pluck(‘last_name’) .distinct().count() Count unique last names with ReQL: Count the number of items
15. Understanding ReQL RethinkDB’s query language embeds natively into your programming language. • Compose queries by chaining • Queries are executed and distributed on the server • Python, Ruby, JavaScript, and 20+ other languages supported
16. What can you do with ReQL? • Transformations: map, orderBy, skip, limit, slice • Aggregations: group, reduce, count, sum, avg, min, max, distinct, contains • Documents: row, pluck, without, merge, append, difference, keys, hasFields, spliceAt • Writing: insert, update, replace, delete • Control: forEach, range, branch, do, coerceTo, expr
17. Changefeeds work on queries r.table(‘user_profiles’) .filter(r.row(‘likes’).gt(30)) .changes() Get notified when a user profile gets over 30 likes:
18. Changefeeds work on queries r.table(‘user_profiles’) .filter(r.row(‘likes’).gt(30)) .changes() Get notified when a user profile gets over 30 likes:
19. Changefeeds work on queries r.table(‘user_profiles’) .filter(r.row(‘likes’).gt(30)) .changes() Get notified when a user profile gets over 30 likes: Clients can subscribe to this realtime stream of updates.
20. Example: realtime questions questions.rethinkdb.com Let’s play with changefeeds: Check out the code yourself: github.com/mglukhovsky/realtime-questions
21. Example: realtime questions Questions server Questions server Dashboard server RethinkDB cluster Changes are pushed to each stateless app server.
22. Advancing the realtime web The push access model simplifies realtime architecture. One source of truth makes it easy to manage state. RethinkDB is the first database for the realtime web. Polling for data is slow, cumbersome, hard to maintain.
23. Learn more about RethinkDB Get started: rethinkdb.com/install Read the docs: rethinkdb.com/docs Follow on Twitter: @rethinkdb