This document summarizes the new features in MongoDB 2.4 across development, operations, performance, security, and enterprise capabilities. Key improvements include enhanced geospatial features using GeoJSON, new aggregation framework features, text search support, updated update operators like $push with $each and $slice, index operation management tools, and role-based access controls. Performance is improved through the new V8 JavaScript engine and faster counting and indexing. Enterprise additions are advanced security options, expanded monitoring, and certified operating system support.

1. CTO, 10gen
Eliot Horowitz
What's New in MongoDB
2.4

2. Improvements made across…
• Development
• Operations
• Performance
• Security
• Enterprise Features

3. MongoDB 2.4
Developer Improvements

4. Geospatial

5. New Geospatial Features
• Polygon intersections
• More accurate spherical model
• $near and $within work with Aggregation
Framework
• Analytics now location-aware

6. GeoJSON
• Geospatial interchange format based on JSON
• Supports Points, LineStrings & Polygons
• Complete spec available at http://geojson.org

7. Point1 = {
type : "Point",
coordinates : [-73.947807, 40.663973]
}
somePoly = {
type : "Polygon",
coordinates : [[[40,5], [40,6],
[41,6], [41,5], [40,5]]]
}
GeoJSON

8. $GeoIntersects
• Leverages GeoJSON
• Geospatial query operator that selects all
locations that intersect with a GeoJSON object
• Uses spherical geometry

9. point1 = { type: "Point", coordinates: [40, 5.5]}
line1 = { type: "LineString",
coordinates: [[40, 3.5], [40, 4.5]]};
somePoly = { type : "Polygon",
coordinates : [[[40,5], [40,6],
[41,6], [41,5], [40,5]]]};
res = c.find({ geo : {
"$geoIntersects" :
{"$geometry" : somePoly}
}});
$GeoIntersects

10. Aggregation Framework

11. New Aggregation Framework
Features
• Introduced in 2.2, came of age in 2.4
• Performance Improvements
• 3 – 5 x faster
• Geo $near and $within support
• $concat support
• Support for Binary Data (pass through)

12. Text Search (beta)

13. Text Search (beta)
• Real-time indexes
• Case-insensitive
• Stemming, tokenization & stop words for 15 languages
• Index size is comparable with other full text search
implementations (larger than standard MongoDB
indexes)
• BETA status… please use in dev & give feedback

14. Stemming Examples
• { walk, walked, walking, walks } ⇒ walk
• {magazine, magazines, magazine’s } ⇒
magazine
• {runs, running, run, ran } ⇒ { run, ran }

15. Examples of English Stop
Words
{
am, themselves, of, before, here, whi
le, what's, myself, ought, me, the, int
o, about, this, do, can't, a, ... }

16. Option 1: on the command line
$ mongod --setParameter textSearchEnabled=true
Option 2: as admin command to mongod or mongos
> db.adminCommand(
{ setParameter: 1, textSearchEnabled: true }
)
Enabling Text Search

17. db.t.ensureIndex(
{ title: "text", post: "text" },
{ weights: { title: 10, post: 5 }}
)
Create a Text Search Index

18. db.t.runCommand(
"text",
{ search: ""my first blog entry"" }
);
Run a Text Search Command

19. {
"queryDebugString":"blog|entri|first||||my first blog entry||",
"language" : "english",
"results" : [{
"score" : 12,
"obj" : {
"_id" : 1,
"title" : "1st post",
"post" : "this is my first blog entry."
}}],
"stats" : {
"nscanned" : 7,
"nscannedObjects" : 0,
"n" : 0,
"nfound" : 1,
"timeMicros" : 122
},
"ok" : 1
}
Text Search Result
Note: debug string shows the stemmed terms, stop-words deleted

20. New Update Operators

21. Capped Arrays
• Provides the ability to manipulate arrays with
more control than ever before
• $push now supports the following:
• $each permits pushing multiple entries onto an
array
• $slice maintains a fixed size array
• Can be stacked with $sort

22. db.students.update(
{ _id: 1 },
{ $push: {
scores: {
$each: [
{ attempt: 3, score: 7 },
{ attempt: 4, score: 4 } ],
$sort: { score: 1 },
$slice: -3
}
}}
)
Top 3 Scores

23. New Upsert Operator

24. db.products.update(
{ _id: 1 },
{ $setOnInsert: { defaultQty: 500, inStock: true },
$set: { item: "apple" } },
{ upsert: true }
)
$setOnInsert

25. MongoDB 2.4
Operational Improvements

26. Hash-based Sharding

27. Hash-based Sharding
• Easier to manage clusters
• Less rebalancing
• More event distribution for reads and writes
• Lower potential performance from range based, but
more consistent.
• The hash stored in the hashed index is 64 bits of the
128 bit md5 hash
• MongoDB can use the hashed index to support equality
queries, but hashed indexes do not support range
queries.

28. db.activeCollection.ensureIndex(
{ field_to_hash: "hashed" }
)
Creating a Hashed Shard Key

29. Working Set Analyzer

30. Working Set Analyzer
• Working Set: The set of data kept in memory
• MongoDB performance best when working
set < RAM
• Working set analyzer measures resources used
over time
• Leads to more efficient MongoDB usage

31. db.serverStatus( { workingSet: 1 } )
db.runCommand( { serverStatus: 1, workingSet: 1 } )
"workingSet" : {
"note" : "thisIsAnEstimate",
"pagesInMemory" : <num>,
"computationTimeMicros" : <num>,
"overSeconds" : num
},
MongoStatus

32. Index Operation
Management

33. Index Operation Management
• A single mongod instance can build multiple
indexes in the background at the same time.
• db.killOp() can now kill foreground index builds
• Improved validation of index types

34. db.currentOp()
{
"inprog" : [ {
"opid" : 45,
"active" : true,
"secs_running" : 2,
"op" : "insert",
"ns" : "test.system.indexes",
...
}]
}
db.killOp(45)
Index Operation Management

35. Replication
Improvements

36. Role Based Privileges
Replication Improvements
• Better detection of network hiccups (less false
negatives)
• Faster initial sync when adding new secondary

37. MongoDB 2.4
Performance
Improvements

38. V8 JavaScript Engine
• Affects all JS processing including
MapReduce, the shell and $where queries
• Greater concurrency
• User feedback very positive indicating dramatic
improvement in overall processing time with new
V8

39. Improvements All Over
• Aggregation 3x – 5x faster
• Faster Counting
– Low-cardinality index-based counts up to 20x faster
– Better performance on counting, e.g., count all the
males/females in my user list
• Faster $elemMatch

40. MongoDB 2.4
Security Improvements

41. Role Based Privileges
Role Based Privileges
• Builds on access controls introduced in 2.2
• Users granted roles that have specific privileges per
database
• Users can have multiple roles
• Roles include
– read
– readWrite
– userAdmin
– dbAdmin
– clusterAdmin

42. Role Based Privileges
Enhanced SSL Support
• Supported in open source edition of MongoDB
• Must be compiled using --ssl flag
• Uses a standard .pem file that contains the SSL
certificate and key
• Complete directions available in the MongoDB
documentation
http://docs.mongodb.org/manual/administration/ssl/

43. Introducing MongoDB
Enterprise 2.4

44. MongoDB Enterprise
• Advanced Security
– Kerberos authentication protocol
– SSLsupportbuilt in
• Monitoring
– On-PremMonitoring- visualization,alerts on 100+ system metrics
– Includes same featuresas (MMS)
• Enterprise Software Integration
– SNMPsupports integration w/popularmonitoring tools (e.g., Nagios )
• Certified OS Support
– Red Hat/CentOS,Ubuntu andAmazon Linux

45. Subscriptions
Basic Standard Enterprise
Edition MongoDB MongoDB MongoDB Enterprise
SLA 4 hours 1 Hour 30 Minutes
Support
9am – 9pm ET
M – F
24x7x365 24x7x365
License AGPL Commercial Commercial
Price per Host $2,500 $5,000 $7,500