MongoDB - Grails Introduction

1. Chris Harris Email : charris@10gen.com Twitter : cj_harris5 Grails Introduction Thursday, 17 May 12
2. Terminology RDBMS MongoDB Table Collection Row(s) JSON Document Index Index Join Embedding & Linking Partition Shard Partition Key Shard Key Thursday, 17 May 12
3. Here is a “simple” SQL Model mysql> select * from book; +----+----------------------------------------------------------+ | id | title | +----+----------------------------------------------------------+ | 1 | The Demon-Haunted World: Science as a Candle in the Dark | | 2 | Cosmos | | 3 | Programming in Scala | +----+----------------------------------------------------------+ 3 rows in set (0.00 sec) mysql> select * from bookauthor; +---------+-----------+ | book_id | author_id | +---------+-----------+ | 1 | 1 | | 2 | 1 | | 3 | 2 | | 3 | 3 | | 3 | 4 | +---------+-----------+ 5 rows in set (0.00 sec) mysql> select * from author; +----+-----------+------------+-------------+-------------+---------------+ | id | last_name | first_name | middle_name | nationality | year_of_birth | +----+-----------+------------+-------------+-------------+---------------+ | 1 | Sagan | Carl | Edward | NULL | 1934 | | 2 | Odersky | Martin | NULL | DE | 1958 | | 3 | Spoon | Lex | NULL | NULL | NULL | | 4 | Venners | Bill | NULL | NULL | NULL | +----+-----------+------------+-------------+-------------+---------------+ 4 rows in set (0.00 sec) Thursday, 17 May 12
4. The Same Data in MongoDB { "_id" : ObjectId("4dfa6baa9c65dae09a4bbda5"), "title" : "Programming in Scala", "author" : [ { "first_name" : "Martin", "last_name" : "Odersky", "nationality" : "DE", "year_of_birth" : 1958 }, { "first_name" : "Lex", "last_name" : "Spoon" }, { "first_name" : "Bill", "last_name" : "Venners" } ] } Thursday, 17 May 12
5. GORM Install Thursday, 17 May 12
6. grails install-plugin mongodb Thursday, 17 May 12
7. grails uninstall-plugin hibernate or static mapWith = "mongo" Thursday, 17 May 12
8. GORM CRUD Operations Thursday, 17 May 12
9. class Person { String firstName String lastName Address address static embedded = ['address'] } Domain Class - Embedded Thursday, 17 May 12
10. class Person { String firstName String lastName Address address List otherAddresses static embedded = ['address', 'otherAddresses'] } Domain Class - List Thursday, 17 May 12
11. new Person (firstName: "Chris").save() class Person { String firstName String lastName Address address List otherAddresses static embedded = ['address', 'otherAddresses'] } Domain Class - Save Thursday, 17 May 12
12. Person.findByFirstName ("Chris") Person.findByLastName ("Harris") Domain Class - Dynamic Finders Thursday, 17 May 12
13. def p = new Person(firstName:”Chris”) p["city"]="London" p.save() Domain Class - Dynamic Attributes Thursday, 17 May 12
14. MongoDB and Groovy Thursday, 17 May 12
15. def mongo = new Mongo() MongoDB Connection Pool Thursday, 17 May 12
16. def db = mongo.getDB("mydb") Note : MongoDB will create the database if it does not exist Getting a Database Thursday, 17 May 12
17. Cursors > var c = db.test.find({x: 20}).skip(20).limit(10)> c.next() > c.next() ... $gt, $lt, $gte, $lte, $ne, $all, $in, $nin, $or, $not, $mod, $size, $exists, $type, $elemMatch query first N results + cursor id getMore w/ cursor id next N results + cursor id or 0 ... Thursday, 17 May 12
18. Replication Thursday, 17 May 12
19. Types of outage • Planned • Hardware upgrade • O/S or file-system tuning • Relocation of data to new file-system / storage • Software upgrade • Unplanned • Hardware failure • Data center failure • Region outage • Human error • Application corruption Thursday, 17 May 12
20. Replica Sets • Data Protection • Multiple copies of the data • Spread across Data Centers, AZs • High Availability • Automated Failover • Automated Recovery Thursday, 17 May 12
21. Replica Sets Primary Secondary Secondary Read Write Read Read App Asynchronous Replication Thursday, 17 May 12
22. Replica Sets Primary Secondary Secondary Read Write Read Read App Thursday, 17 May 12
23. Replica Sets Primary Primary Secondary Read Write Read Automatic Election of new Primary App Thursday, 17 May 12
24. Replica Sets Recovering Primary Secondary Read Write Read New primary serves data App Thursday, 17 May 12
25. Replica Sets Secondary Primary Secondary Read Write Read Read App Thursday, 17 May 12
26. Elections During an election • Most up to date • Highest priority • Less than 10s behind failed Primary Thursday, 17 May 12
27. Types of Durability with MongoDB • Fire and forget • Wait for error • Wait for fsync • Wait for journal sync • Wait for replication Thursday, 17 May 12
28. Fire and forget Driver Primary apply in memory write Thursday, 17 May 12
29. Wait for Journal Sync Driver Primary apply in memory write Write to journal Thursday, 17 May 12
30. Wait for replication Driver Primary apply in memory write Secondary replicate Thursday, 17 May 12
31. import com.mongodb.WriteConcern class Person { String name static mapping = { writeConcern WriteConcern.SAFE } } Domain Class - Write Concern Thursday, 17 May 12
32. db.person.insert([first:"Chris",last:"Harris"], WriteConcern.NORMAL) Write Concern in Groovy Thursday, 17 May 12
33. Indexes Thursday, 17 May 12
34. db.blogs.ensureIndex({author: 1}) 1 = ascending -1 = descending An index on _id is automatic. For more use ensureIndex: Creating Indexes Thursday, 17 May 12
35. class Person { String name static mapping = { name index:true } } Domain Class - Index Thursday, 17 May 12
36. Compound Indexes db.blogs.save({ author: "James", ts: new Date() ... }); db.blogs.ensureIndex({author: 1, ts: -1}) Thursday, 17 May 12
37. db.blogs.save({ title: "My First blog", comments: [ {author: "James", ts : new Date()} ] }); db.blogs.ensureIndex({"comments.author": 1}) db.blogs.find({"comments.author": "James"}) Indexing Embedded Arrays Thursday, 17 May 12
38. db.blogs.save({ loc: { long: 40.739037, lat: 40.739037 } }); db.blogs.save({ loc: [40.739037, 40.739037] }); db.blogs.ensureIndex({"loc": "2d"}) Geospatial • Geo hash stored in B-Tree • First two values indexed Thursday, 17 May 12
39. class Hotel { String name List location static mapping = { location geoIndex:true } } Domain Class - Geospacial Thursday, 17 May 12
40. Sharding Thursday, 17 May 12
41. http://community.qlikview.com/cfs-filesystemfile.ashx/__key/CommunityServer.Blogs.Components.WeblogFiles/ theqlikviewblog/Cutting-Grass-with-Scissors-_2D00_-2.jpg Thursday, 17 May 12
42. http://www.bitquill.net/blog/wp-content/uploads/2008/07/pack_of_harvesters.jpg Thursday, 17 May 12
43. MongoDB Scaling - Single Node write read node_a1 Thursday, 17 May 12
44. Write scaling - add Shards write read shard1 node_c1 node_b1 node_a1 shard2 node_c2 node_b2 node_a2 Thursday, 17 May 12
45. Write scaling - add Shards write read shard1 node_c1 node_b1 node_a1 shard2 node_c2 node_b2 node_a2 shard3 node_c3 node_b3 node_a3 Thursday, 17 May 12
46. MongoDB Sharding • Automatic partitioning and management • Range based • Convert to sharded system with no downtime • Fully consistent Thursday, 17 May 12
47. How MongoDB Sharding works > db.posts.save( {age:40} ) -∞ +∞ -∞ 40 41 +∞ •Data in inserted •Ranges are split into more “chunks” Thursday, 17 May 12
48. How MongoDB Sharding works > db.posts.save( {age:40} ) > db.posts.save( {age:50} ) > db.posts.save( {age:60} ) -∞ +∞ -∞ 40 41 +∞ 41 50 51 +∞ 61 +∞ 51 60 Thursday, 17 May 12
49. Balancing Shard 1 Shard 2 Shard 3 Shard 4 5 9 1 6 10 2 7 11 3 8 12 4 17 21 13 18 22 14 19 23 15 20 24 16 29 33 25 30 34 26 31 35 27 32 36 28 41 45 37 42 46 38 43 47 39 44 48 40 mongos balancer config config config Chunks! Thursday, 17 May 12
50. Balancing mongos balancer config config config Shard 1 Shard 2 Shard 3 Shard 4 5 9 1 6 10 2 7 11 3 8 12 4 21 22 23 24 33 34 35 36 45 46 47 48 Imbalance Imbalance Thursday, 17 May 12
51. Balancing mongos balancer Move chunk 1 to Shard 2 config config config Shard 1 Shard 2 Shard 3 Shard 4 5 9 1 6 10 2 7 11 3 8 12 4 21 22 23 24 33 34 35 36 45 46 47 48 Thursday, 17 May 12
52. Balancing mongos balancer config config config Shard 1 Shard 2 Shard 3 Shard 4 5 9 6 10 2 7 11 3 8 12 4 21 22 23 24 33 34 35 36 45 46 47 48 1 Thursday, 17 May 12
53. Balancing mongos balancer config config config Shard 1 Shard 2 Shard 3 Shard 4 5 9 6 10 2 7 11 3 8 12 4 21 22 23 24 33 34 35 36 45 46 47 48 1 Thursday, 17 May 12
54. Balancing mongos balancer Chunk 1 now lives on Shard 2 config config config Shard 1 Shard 2 Shard 3 Shard 4 5 9 1 6 10 2 7 11 3 8 12 4 21 22 23 24 33 34 35 36 45 46 47 48 Thursday, 17 May 12
55. conferences, appearances http://www.10gen.com/events and meetups http://www.meetup.com/London-MongoDB-User-Group http://www.meetup.com/London-Data-Bar Questions? Chris Harris Email : charris@10gen.com Twitter : cj_harris5 Thursday, 17 May 12