MongoDB and Play! Framework workshop
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This document provides an overview and agenda for a startup tech arsenal workshop focusing on MongoDB. The summary includes: Part I covers basic MongoDB concepts like collections, documents and fields. It demonstrates common operations like insert, update, find and backups. It also discusses data modeling considerations. Part II introduces the Play! web framework for coding examples. Attendees will get hands-on practice with challenges like adding, searching and backing up employee data. The workshop aims to equip attendees with weapons like MongoDB and Play! and provide coding time to work through examples and challenges.
![Operations
Insert listings - insert
db.listings.insert( { title: "Erasmus Residence", rentable: true } )
db.listings.insert( {title: "xpto", rentable: true, location: [{city:
"lisbon", coordinates: {latitude: 0, longitude: 90} } ] } )](https://image.slidesharecdn.com/mongodbplayworkshop-130823084136-phpapp01/85/MongoDB-and-Play-Framework-workshop-10-320.jpg)
![Search listings - find (1 - 2)
Syntax: find( < query>, <projection>)
Projection
db.listings.find( { title: "Uniplaces Mega mansion"}, {rentable: 1} )
Logical operators ($and)
db.listings.find({ $and: [{ title: "Uniplaces Mega Mansion"}, {rentable: "false"}] })
Comparison operators ($gte)
db.listings.find( { "apartment_details.bedrooms" : {$gte: 2 } }, { title: 1} )
Operations](https://image.slidesharecdn.com/mongodbplayworkshop-130823084136-phpapp01/85/MongoDB-and-Play-Framework-workshop-14-320.jpg)
![● MongoDB does not support Joins
● Embedded Documents
{
"title": "Uniplaces Mega mansion",
"bedrooms" : [
{
"price" : 500,
"area": 25
},
{
"price" : 700,
"area": 30
},
]
}
db.listings.find( {bedrooms: { $elemMatch: {price: { $gt: 20 }, area: 25} } })
Data modeling](https://image.slidesharecdn.com/mongodbplayworkshop-130823084136-phpapp01/85/MongoDB-and-Play-Framework-workshop-16-320.jpg)
MongoDB and Play! Framework workshop
- 1. Startup tech arsenal! João Vazão Vasques
- 3. AGENDA
- 4. PART I - MongoDB
- 5. MongoDB topics ● Basic concepts ● Operations ● Data modeling ● Performance and tools
- 6. Basic concepts 1-2 ● NoSQL ● No transactions ○ Eventual consistency ● No schema ○ Flexibility: code defines your schema ● Scaling (Horizontal scaling) ● Document oriented ○ BJSON
- 8. So we have... Databases containing collections. A collection is made up of documents. Each document is made up of fields
- 9. Operations ● Document example (Uniplaces listing) { "title": "Uniplaces Mega mansion", "rentable": false, "location" : { "city" : "Lisboa", "coordinates" : { "longitude" : -9.145782599999961, "latitude" : 38.7234037 } }, "apartment_details" : { "bathrooms" : 2, "bedrooms" : 6, }, }
- 10. Operations Insert listings - insert db.listings.insert( { title: "Erasmus Residence", rentable: true } ) db.listings.insert( {title: "xpto", rentable: true, location: [{city: "lisbon", coordinates: {latitude: 0, longitude: 90} } ] } )
- 11. Operations Update listings - update Syntax: update( < query>, <update>, <options>) Problem! We want to make "Mansion" rentable. Solution (easy)! db.listings.update( { title: "Uniplaces Mega Mansion"}, {rentable: true } ) Search for Mega Mansion and...
- 13. Operations Update listings 2 -2 Reason: second parameter replaces the original. We replaced the entire document with a new one. Ups! Solution - $set Used when you want to change a value of one, or a few, fields db.listings.update( { title: "Uniplaces Mega Mansion"}, { $set: {rentable: true } } ) Other update modifiers: $inc, $unset, $push, $pop
- 14. Search listings - find (1 - 2) Syntax: find( < query>, <projection>) Projection db.listings.find( { title: "Uniplaces Mega mansion"}, {rentable: 1} ) Logical operators ($and) db.listings.find({ $and: [{ title: "Uniplaces Mega Mansion"}, {rentable: "false"}] }) Comparison operators ($gte) db.listings.find( { "apartment_details.bedrooms" : {$gte: 2 } }, { title: 1} ) Operations
- 15. Search listings - find (2 - 2) Ordering (sort: -1 descending, 1 ascending) db.listings.find({ $gte: { "apartment_details.bedrooms" : 2 }).sort ("apartment_details.bedrooms": -1) Paging (limit and skip) db.listings.find().limit(3).skip(1) Operations
- 16. ● MongoDB does not support Joins ● Embedded Documents { "title": "Uniplaces Mega mansion", "bedrooms" : [ { "price" : 500, "area": 25 }, { "price" : 700, "area": 30 }, ] } db.listings.find( {bedrooms: { $elemMatch: {price: { $gt: 20 }, area: 25} } }) Data modeling
- 17. Considerations: ● Geography ● System errors ○ ensure your backups can "survive" ● Production constraints ○ Schedule according to system usage ● Database configuration ○ Replication & Sharding Backups 1 -3
- 18. Approaches to backup MongoDB systems ● Binary database dumps ○ Small ○ Don't include index content and padding ○ Cannot reflect single moment in time ● Filesystem snapshots ○ Large backup sizes ○ Accurate ○ Require filesystem and OS tools ○ Can reflect a single moment in time ■ Note: in sharding all writes must be suspended Backups 2-3
- 19. Backup and restore example ● Backup database > mongodump -v -d test -o dump ● Restore database > mongorestore -v --db test dump Backups 3-3
- 20. ● Writes to primary (only) ○ A write is fully committed once it has replicated to a majority of servers in the set ● Reads to primary and secondary ● Consensus election in case of primary fail Replica Sets Secondary Secondary Primary W W W Secondary W
- 21. END OF PART I
- 22. Part II - Coding Time!
- 23. Part II - Coding Time! Weapons we'll be using
- 24. ● Web framework written in Scala & Java ● MVC paradigm ● Built on Akka ● Built in testing tools ● IDE support (Eclipse and IntelliJ IDEA) About Play!
- 25. MVC Model - View - Controller
- 26. Anatomy of a Play! application
- 29. Download the demo project on Github ● https://github.com/JoaoVasques/mongodb-workshop Challenges: ● Fire Employee ● Search employee ● Create a backup of the database and restore it Hands on time!!!
- 30. ● engineering.linkedin.com ● blog.twitter.com/engineering ● facebook.com/Engineering ● engineering.foursquare.com ● nerds.airbnb.com Cool tech blogs
- 31. Thank you!