This is the first webinar of a Back to Basics series that will introduce you to the MongoDB database, what it is, why you would use it, and what you would use it for.
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Course Agenda
Date Time Webinar
05-May-2016 14:00 GMT Introduction to NoSQL
24-May-2016 14.00 GMT Your First MongoDB Application
14-Jun-2016 14:00 GMT Schema Design – Thinking in Documents
05-July-2016 14:00 GMT Advanced Indexing : Text and Geo-Spatial Indexes
14-July-2016 14:00 GMT Introduction to the Aggregation Framework
11-Aug-2016 14:00 GMT Production Deployment
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Agenda for Today
• Why NoSQL
• The different types of NoSQL database
• Detailed overview of MongoDB
• MongoDB data durability – Replica Sets
• MongoDB scalability – Sharding
• Q&A
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Key Value Stores
• An associative array
• Single key lookup
• Very fast single key lookup
• Not so hot for “reverse lookups”
Key Value
12345 4567.3456787
12346 { addr1 : “The Grange”, addr2: “Dublin” }
12347 “top secret password”
12358 “Shopping basket value : 24560”
12787 12345
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Revision : Row Stores (RDBMS)
• Store data aligned by rows (traditional RDBMS, e.g MySQL)
• Reads retrieve a complete row everytime
• Reads requiring only one or two columns are wasteful
ID Name Salary Start Date
1 Joe D $24000 1/Jun/1970
2 Peter J $28000 1/Feb/1972
3 Phil G $23000 1/Jan/1973
1 Joe D $24000 1/Jun/1970 2 Peter J $28000 1/Feb/1972 3 Phil G $23000 1/Jan/1973
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How a Column Store Does it
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ID Name Salary Start Date
1 Joe D $24000 1/Jun/1970
2 Peter J $28000 1/Feb/1972
3 Phil G $23000 1/Jan/1973
Joe D Peter J Phil G $24000 $28000 $23000 1/Jun/1970 1/Feb/1972 1/Jan/1973
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Why is this Attractive?
• A series of consecutive seeks can retrieve a column efficiently
• Compressing similar data is super efficient
• So reads can grab more data off disk in a single seek
• How do I align my rows? By order or by inserting a row ID
• IF you just need a small number of columns you don’t need to
read all the rows
• But:
– Updating and deleting by row is expensive
• Append only is preferred
• Better for OLAP than OLTP
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Graph Stores
• Store graphs (edges and vertexes)
• E.g. social networks
• Designed to allow efficient traversal
• Optimised for representing connections
• Can be implemented as a key value stored with the ability to store
links
• If your use case is not a graph you don’t need a graph database
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Multi-Model Databases
• Combine multiple storage/access models
• Often Graph plus “something else”
• Fixes the “polyglot persistence” issue of keeping multiple
independent databases consistent
• The “new new thing” in NoSQL Land
• Expect to hear more noise about these kinds of databases
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Document Store
• Not PDFs, Microsoft Word or HTML
• Documents are nested structures created using Javascript Object Notation (JSON)
{
name : “Joe Drumgoole”,
title : “Director of Developer Advocacy”,
Address : {
address1 : “Latin Hall”,
address2 : “Golden Lane”,
eircode : “D09 N623”,
}
expertise: [ “MongoDB”, “Python”, “Javascript” ],
employee_number : 320,
location : [ 53.34, -6.26 ]
}
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MongoDB Understands JSON Documents
• From the very first version it was a native JSON database
• Understands and can index the sub-structures
• Stores JSON as a binary format called BSON
• Efficient for encoding and decoding for network transmission
• MongoDB can create indexes on any document field
• (We will cover these areas in detail later on in the course)
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Why Documents?
• Dynamic Schema
• Elimination of Object/Relational Mapping Layer
• Implicit denormalisation of the data for performance
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Why Documents?
• Dynamic Schema
• Elimination of Object/Relational Mapping Layer
• Implicit denormalisation of the data for performance
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MongoDB is Full Featured
Rich
Queries
• Find Paul’s cars
• Find everybody in London with a car
between 1970 and 1980
Geospatial
• Find all of the car owners within 5km of
Trafalgar Sq.
Text Search
• Find all the cars described as having
leather seats
Aggregation
• Calculate the average value of Paul’s car
collection
Map
Reduce
• What is the ownership pattern of colors by
geography over time (is purple trending in
China?)
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Scalability with Sharding
• Shard key partitions the content
• MongoDB automatically balances the cluster
• Shards can be added dynamically to a live system
• Rebalancing happens in the background
• Shard key is immutable
• Shard key can vector queries to a specific shard
• Queries without a shard key are sent to all members
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Query Routing
• With a sharded cluster we use a routing layer to guide queries
• We use a daemon called MongoS (Mongo Shard Router)
• Daemon is stateless
• Can run as many as required
• Typically one per app server
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Summary
• Why NoSQL exists
• The types of NoSQL database
• The key features of MongoDB
• Data durability in MongoDB
• Scalability in MongoDB
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Next Webinar – Your First MongoDB Application
• 24th May 2016 – 14:00 GMT.
• Make sure to register if you haven’t already
• Learn how to build your first MongoDB application
• Create databases and collections
• Look at queries
• Build indexes
• Start to understand performance
• Register at: http://bit.ly/1UA4BGM
• Send feedback to back-to-basics@mongodb.com
Delighted to have you here. Hope you can make it to all the sessions. Sessions will be recorded so we can send them out afterwards so don’t worry if you miss one.
If you have questions please pop them in the sidebar.
A lot of people expect us to come in and bash relational database or say we don’t think they’re good. And that’s simply not true.
Relational databases has laid the foundation for what you’d want out of a database, and we absolutely think there are capabilities that remain critical today
Expressive query language & secondary Indexes. Users should be able to access and manipulate their data in sophisticated ways – and you need a query language that let’s you do all that out of the box. Indexes are a critical part of providing efficient access to data. We believe these are table stakes for a database.
Strong consistency. Strong consistency has become second nature for how we think about building applications, and for good reason. The database should always provide access to the most up-to-date copy of the data. Strong consistency is the right way to design a database.
Enterprise Management and Integrations. Finally, databases are just one piece of the puzzle, and they need to fit into the enterprise IT stack. Organizations need a database that can be secured, monitored, automated, and integrated with their existing IT infrastructure and staff, such as operations teams, DBAs, and data analysts.
But of course the world has changed a lot since the 1980s when the relational database first came about.
First of all, data and risk are significantly up.
In terms of data
90% data created in last 2 years - think about that for a moment, of all the data ever created, 90% of it was in the last 2 years
80% of enterprise data is unstructured - this is data that doesn’t fit into the neat tables of a relational database
Unstructured data is growing 2X rate of structured data
At the same time, risks of running a database are higher than ever before. You are now faced with:
More users - Apps have shifted from small internal departmental system with thousands of users to large external audiences with millions of users
No downtime - It’s no longer the case that apps only need to be available during standard business hours. They must be up 24/7.
All across the globe - your users are everywhere, and they are always connected
On the other hand, time and costs are way down.
There’s less time to build apps than ever before. You’re being asked to:
Ship apps in a few months not years - Development methods have shifted from a waterfall process to an iterative process that ships new functionality in weeks and in some cases multiple times per day at companies like Facebook and Amazon.
And costs are way down too. Companies want to:
Pay for value over time - Companies have shifted to open-source business and SaaS models that allow them to pay for value over time
Use cloud and commodity resources - to reduce the time to provision their infrastructure, and to lower their total cost of ownership
Because the relational database was not designed for modern applications, starting about 10 years ago a number of companies began to build their own databases that are fundamentally different. The market calls these NoSQL.
NoSQL databases were designed for this new world…
Flexibility. All of them have some kind of flexible data model to allow for faster iteration and to accommodate the data we see dominating modern applications. While they all have different approaches, what they have in common is they want to be more flexible.
Scalability + Performance. Similarly, they were all built with a focus on scalability, so they all include some form of sharding or partitioning. And they're all designed to deliver great performance. Some are better at reads, some are better at writes, but more or less they all strive to have better performance than a relational database.
Always-On Global Deployments. Lastly, NoSQL databases are designed for highly available systems that provide a consistent, high quality experience for users all over the world. They are designed to run on many computers, and they include replication to automatically synchronize the data across servers, racks, and data centers.
However, when you take a closer look at these NoSQL systems, it turns out they have thrown out the baby with the bathwater. They have sacrificed the core database capabilities you’ve come to expect and rely on in order to build fully functional apps, like rich querying and secondary indexes, strong consistency, and enterprise management.
MongoDB was built to address the way the world has changed while preserving the core database capabilities required to build modern applications.
Our vision is to leverage the work that Oracle and others have done over the last 40 years to make relational databases what they are today, and to take the reins from here. We pick up where they left off, incorporating the work that internet pioneers like Google and Amazon did to address the requirements of modern applications.
MongoDB is the only database that harnesses the innovations of NoSQL and maintains the foundation of relational databases – and we call this our Nexus Architecture.
Think redis, memcached or Couchbase.
Column stores you know and love, HP Vertica, Cassandra.
Rich queries, text search, geospatial, aggregation, mapreduce are types of things you can build based on the richness of the query model.