ForwardJS - RethinkDB - Getting Started

Transcript

1. RethinkDB The database for the realtime web ForwardJS San Francisco, California July 30, 2015
2. Jorge Silva @thejsj Developer Evangelist @ RethinkDB
3. Schedule 1. What is RethinkDB? 2. RethinkDB query language 3. Working with changefeeds 4. Using RethinkDB with Node.js 5. Tutorial: Building a chat app
4. Introduction What is RethinkDB?
5. 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
6. Built for Realtime Apps • Subscribe to change notifications from database queries (changefeeds) • No more polling — the database pushes changes to your app • Reduce the amount of plumbing needed to stream live updates
7. Built for Realtime Apps • Having your database push changes keeps your database as the central source of truth • Having a central source of truth simplifies your architecture
8. Power and Convenience • Highly expressive query language • Relational features like table joins • Powerful admin UI with point- and-click cluster management
9. RethinkDB Structure Database → Table → Document MySQL: Database → Table → Row MongoDB: Database → Collection → Document
10. Sample Document { "name": "Will Riker", "position": "Commander", "height": 193, "birthdate": Mon Aug 19 2335, "ships": [ { "name": "USS Pegasus" }, { "name": "USS Potemkin" }, { "name": "USS Enterprise" }, ], ... }
11. Differences with Firebase • Firebase is a cloud service, not an open-source database • Because Firebase is not a database, it has limited querying abilities • Firebase is made to be queried from the browser
12. Differences with MongoDB • RethinkDB supports joins and subqueries • MongoDB only supports the traditional query-response model. You can't subscribe to queries.
13. Introduction to ReQL RethinkDB query language
14. Introduction to ReQL • ReQL embeds natively into your programming language • Compose ReQL queries by chaining commands
15. Anatomy of a ReQL Query r.table("users") .pluck("last_name") .distinct().count() Number of unique last names
16. Anatomy of a ReQL Query r.table("users") .pluck("last_name") .distinct().count() Access a database table
17. Anatomy of a ReQL Query r.table("users") .pluck("last_name") .distinct().count() Isolate a document property
18. Anatomy of a ReQL Query r.table("users") .pluck("last_name") .distinct().count() Consolidate duplicate values
19. Anatomy of a ReQL Query r.table("users") .pluck("last_name") .distinct().count() Display the number of items
20. Sample ReQL Queries r.table("users") .filter(r.row("age").gt(30)) r.table(“posts") .eqJoin(“userId”, r.table(“users”)) .zip() r.table("posts") .filter({status: "draft"}) .update({status: "published"})
21. 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
22. 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
23. 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
24. 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
25. 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
26. Understanding ReQL • All queries are executed by the database, not the client • Client driver translates ReQL queries into wire protocol • In JS use e.g. the mul and gt commands instead of the normal operators
27. Additional ReQL Features • Geospatial indexing for location- based queries • Date and time functions • Support for storing binary objects • Execute http requests using r.http
28. Installation http://rethinkdb.com/install
29. Running Queries https://github.com/thejsj/rethinkdb-workshop
30. Running Queries http://localhost:8080/ http://rethinkdb.thejsj.com:8080/
31. Realtime Updates Working with Changefeeds
32. Subscribe to change notifications on database queries Changefeeds
33. r.table("users").changes() Track changes on the users table Changefeeds
34. Changefeeds • The changes command returns a cursor that receives updates • Each update includes the new and old value of the modified record
35. 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 }
36. 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', ... } }
37. 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' } }
38. 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:
39. Changefeeds r.table("table").get(ID).changes() r.table("table").getAll(ID).changes() r.table("table").between(X, Y).changes() r.table("table").pluck(X, Y, Z).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:
40. Using Changefeeds
41. Building Web Apps Using RethinkDB in Node
42. Client Driver • Use a RethinkDB client driver to access the database in your app • Official drivers available for Ruby, Python, and JavaScript • Third-party drivers available for other languages like Go and Clojure
43. > Client Driver Install the JS client driver from npm in your Node.js project: $ npm install rethinkdb --save
44. Client Driver var r = require("rethinkdb"); r.connect().then(function(conn) { return r.table("users") .insert({name: “Bob”}).run(conn) .finally(function () { conn.close(); }); }).then(function(output) { console.log(output); }); Add Bob to the “users” table
45. Client Driver var r = require("rethinkdb"); r.connect().then(function(conn) { return r.table("users") .insert({name: “Bob"}).run(conn) .finally(function () { conn.close(); }); }).then(function(output) { console.log(output); }); Import the RethinkDB module
46. Client Driver var r = require("rethinkdb"); r.connect().then(function(conn) { return r.table("users") .insert({name: “Bob”}).run(conn) .finally(function () { conn.close(); }); }).then(function(output) { console.log(output); }); Connect to the database
47. Client Driver var r = require("rethinkdb"); r.connect().then(function(conn) { return r.table("users") .insert({name: “Bob”}).run(conn) .finally(function () { conn.close(); }); }).then(function(output) { console.log(output); }); ReQL query that inserts a record
48. Client Driver var r = require("rethinkdb"); r.connect().then(function(conn) { return r.table("users") .insert({name: “Bob”}).run(conn) .finally(function () { conn.close(); }); }).then(function(output) { console.log(output); }); Run the query on a connection
49. Client Driver var r = require("rethinkdb"); r.connect().then(function(conn) { return r.table("users") .insert({name: “Bob"}).run(conn) .finally(function () { conn.close(); }); }).then(function(output) { console.log(output); }); Display query response
50. Client Driver var r = require("rethinkdb"); r.connect().then(function(conn) { return r.table("users") .insert({name: “Bob"}).run(conn) .finally(function () { conn.close(); }); }).then(function(output) { console.log(output); }).error(function(err) { console.log("Failed:", err); }); Handle errors emitted by Promise
51. Using Changefeeds r.connect().then(function(conn) { return r.table("fellowship") .changes().run(conn); }) .then(function(cursor) { cursor.each(function(err, item) { console.log(item); }); }); Display every change on the “fellowship” table
52. Using Changefeeds Attach a changefeed to the table r.connect().then(function(conn) { return r.table("fellowship") .changes().run(conn); }) .then(function(cursor) { cursor.each(function(err, item) { console.log(item); }); });
53. Using Changefeeds Iterate over every value passed into the cursor r.connect().then(function(conn) { return r.table("fellowship") .changes().run(conn); }) .then(function(cursor) { cursor.each(function(err, item) { console.log(item); }); });
54. Using Changefeeds r.connect().then(function(conn) { return r.table("fellowship") .changes().run(conn); }) .then(function(cursor) { cursor.each(function(err, item) { console.log(item); }); }); Display received changes in the console
55. Using Socket.io • Powerful framework for realtime client/server communication • Supports WebSockets, long polling, and other transports • Lets you send JSON messages between your app and frontend
56. Socket.io (Server) var sockio = require("socket.io"); var app = require("express")(); var r = require("rethinkdb"); var io = sockio.listen(app.listen(8090)); r.connect().then(function(conn) { return r.table("players") .orderBy({index: r.desc("score")}) .limit(5).changes().run(conn); }) .then(function(cursor) { cursor.each(function(err, data) { io.sockets.emit("update", data); }); }); Broadcast score changes over Socket.io
57. Socket.io (Server) var sockio = require("socket.io"); var app = require("express")(); var r = require("rethinkdb"); var io = sockio.listen(app.listen(8090)); r.connect().then(function(conn) { return r.table("players") .orderBy({index: r.desc("score")}) .limit(5).changes().run(conn); }) .then(function(cursor) { cursor.each(function(err, data) { io.sockets.emit("update", data); }); }); Load the Socket.io module
58. Socket.io (Server) var sockio = require("socket.io"); var app = require("express")(); var r = require("rethinkdb"); var io = sockio.listen(app.listen(8090)); r.connect().then(function(conn) { return r.table("players") .orderBy({index: r.desc("score")}) .limit(5).changes().run(conn); }) .then(function(cursor) { cursor.each(function(err, data) { io.sockets.emit("update", data); }); }); Instantiate Socket.io server
59. Socket.io (Server) var sockio = require("socket.io"); var app = require("express")(); var r = require("rethinkdb"); var io = sockio.listen(app.listen(8090)); r.connect().then(function(conn) { return r.table("players") .orderBy({index: r.desc("score")}) .limit(5).changes().run(conn); }) .then(function(cursor) { cursor.each(function(err, data) { io.sockets.emit("update", data); }); }); Attach a changefeed to the query
60. Socket.io (Server) var sockio = require("socket.io"); var app = require("express")(); var r = require("rethinkdb"); var io = sockio.listen(app.listen(8090)); r.connect().then(function(conn) { return r.table("players") .orderBy({index: r.desc("score")}) .limit(5).changes().run(conn); }) .then(function(cursor) { cursor.each(function(err, data) { io.sockets.emit("update", data); }); }); Broadcast updates to all Socket.io connections
61. Socket.io (Client) <html> <head> <title>Real-time web app</title> <script src="/socket.io/socket.io.js"></script> <script> var socket = io.connect(); socket.on("update", function(data) { console.log("Update:", data); }); Receive Socket.io updates on frontend
62. Socket.io (Client) <html> <head> <title>Real-time web app</title> <script src="/socket.io/socket.io.js"></script> <script> var socket = io.connect(); socket.on("update", function(data) { console.log("Update:", data); }); Load the Socket.io client script
63. Socket.io (Client) <html> <head> <title>Real-time web app</title> <script src="/socket.io/socket.io.js"></script> <script> var socket = io.connect(); socket.on("update", function(data) { console.log("Update:", data); }); Connect to the Socket.io server
64. Socket.io (Client) <html> <head> <title>Real-time web app</title> <script src="/socket.io/socket.io.js"></script> <script> var socket = io.connect(); socket.on("update", function(data) { console.log("Update:", data); }); Create handler for “update” messages
65. Socket.io (Client) <html> <head> <title>Real-time web app</title> <script src="/socket.io/socket.io.js"></script> <script> var socket = io.connect(); socket.on("update", function(data) { console.log("Update:", data); }); Display update in browser console
66. Tutorial: Building a chat app
67. #1: Clone the repository Clone From GitHub: git clone https://github.com/thejsj/ rethinkdb-workshop.git Download Tarball: https://github.com/thejsj/rethinkdb- workshop/tarball/master
68. #2: Install Dependencies // Go to the project directory cd rethinkdb-workshop // Install dependencies npm install
69. #3: Go to config/default.js Update your RethinkDB database configuration var config = { "rethinkdb": { "host": "localhost", // or rethinkdb.thejsj.com "port": 28015, "db" : "rethinkdb_workshop" // or GITHUB_HANDLE_rethinkdb_workshop },
70. #4: Run Server // Start server npm run dev // or `node server`
71. #4: Go to server/index.js Look for the comments in order to write the correct ReQL queries // Step 1 // Write a query
72. Connections In this app, the `r` object contains a connection. r.table("messages").run(r.conn);
73. #5: Switch database Connect to the following database, so we can all share messages var config = { "rethinkdb": { "host": "rethinkdb.thejsj.com", "port": 29015, "db" : "GITHUB_HANDLE_rethinkdb_workshop" },
74. Next steps • Advanced Commands: `r.do`, `r.branch`, `r.forEach` • Map/Reduce queries • Indexes (multi, compound, index functions, geospatial) • Sharding and replication
75. Questions • RethinkDB website:
 http://rethinkdb.com • Install RethinkDB:
 http://rethinkdb.com/install/ • Email me: jorge@rethinkdb.com • Tweet: @thejsj, @rethinkdb