Introduction to RethinkDB : Big Data Utah

Presentation to RethinkDB given at Utah Big Data Meetup on May 6th, 2015.

Transcript

1. RethinkDB The database for the realtime web Big Data Meetup Utah Salt Lake City, Utah May 6, 2015
2. Jorge Silva @thejsj Developer Evangelist @ RethinkDB
3. Introduction What is RethinkDB?
4. What is RethinkDB? • Open source database for building realtime web applications • NoSQL database that stores schemaless JSON documents • Distributed database that is easy to scale
5. Built for Realtime Apps • Subscribe to change notifications from database queries • No more polling — the database pushes changes to your app • Reduce the amount of plumbing needed to stream live updates
6. RethinkDB Structure Database → Table → Document MySQL: Database → Table → Row MongoDB: Database → Collection → Document
7. Sample Document { "name": "Will Riker", "position": "Commander", "height": 193, "birthdate": Mon Aug 19 2335, "ships": [ { "name": "USS Pegasus" }, { "name": "USS Potemkin" }, { "name": "USS Enterprise" }, ], ... }
8. Introduction to ReQL RethinkDB Query Language
9. Introduction to ReQL • ReQL embeds natively into your programming language • Compose ReQL queries by chaining commands
10. Anatomy of a ReQL Query r.table("users") .pluck("last_name") .distinct().count() Number of unique last names
11. Anatomy of a ReQL Query r.table("users") .pluck("last_name") .distinct().count() Access a database table
12. Anatomy of a ReQL Query r.table("users") .pluck("last_name") .distinct().count() Isolate a document property
13. Anatomy of a ReQL Query r.table("users") .pluck("last_name") .distinct().count() Consolidate duplicate values
14. Anatomy of a ReQL Query r.table("users") .pluck("last_name") .distinct().count() Display the number of items
15. Sample ReQL Queries r.table("users") .filter(r.row("age").gt(30)) r.table("users") .pluck("last_name") .distinct().count() r.table("fellowship") .filter({species: "hobbit"}) .update({species: "halfling"})
16. ReQL Commands • 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. Running Queries http://bit.ly/1JQ8imw
18. Understanding ReQL • Anonymous function must return a valid ReQL expression • Client driver translates ReQL queries into wire protocol • In JS use e.g. the mul and gt commands instead of the normal operators
19. Additional ReQL Features • Geospatial indexing for location- based queries • Date and time functions for time data • Support for storing binary objects
20. Realtime Updates Working with Changefeeds
21. Subscribe to change notifications on database queries Changefeeds
22. Changefeeds Example http://realtime-photo.thejsj.com/
23. r.table("users").changes() Track changes on the users table Changefeeds
24. Changefeeds • The changes command returns a cursor that receives updates • Each update includes the new and old value of the modified record
25. Changefeeds r.table("users").changes() r.table("users") .insert({name: "Bob"}) Changefeed output: { new_val: { id: '362ae837-2e29-4695-adef-4fa415138f90', name: 'Bob', ... }, old_val: null }
26. Changefeeds r.table("users").changes() r.table("users") .filter({name: "Bob"}).delete() Changefeed output: { new_val: null, old_val: { id: '362ae837-2e29-4695-adef-4fa415138f90', name: 'Bob', ... } }
27. Changefeeds r.table("users").changes() r.table("users") .get("362ae837-2e29-4695-adef-4fa415138f90") .update({name: "Bobbby"}) Changefeed output: { new_val: { id: '362ae837-2e29-4695-adef-4fa415138f90', name: 'Bobby' }, old_val: { id: '362ae837-2e29-4695-adef-4fa415138f90', name: 'Bob' } }
28. Changefeeds r.table("players") .orderBy({index: r.desc("score")}) .limit(3).changes() Track top three players by score Chain the changes command to an actual ReQL query:
29. Changefeeds r.table("table").get(ID).changes() r.table("table").getAll(ID).changes() r.table("table").between(X, Y).changes() r.table("table").filter(CONDITION).changes() r.table("table").union(ID).changes() r.table("table").map(FUNCTION).changes() r.table("table").min(INDEX).changes() r.table("table").max(INDEX).changes() r.table("table").orderBy(INDEX) .limit(N).changes() Commands that currently work with changefeeds:
30. Using Changefeeds
31. Cluster Configuration Sharding and replication
32. Sharding and Replication • RethinkDB is designed for clustering and easy scalability • To add a new server to the cluster, just launch it with the join option • Configure sharding and replication per table • Any feature that works with a single database will work in a sharded cluster
33. Add a Server to a Cluster $ rethinkdb --join server:29015 >
34. Clustering
35. Additional Resources • RethinkDB website:
 http://rethinkdb.com • RethinkDB cookbook:
 http://rethinkdb.com/docs/cookbook • RethinkDB installation:
 http://rethinkdb.com/docs/install/