10gen Mongodb Microsoftazure White Paper

7/29/2019 10gen Mongodb Microsoftazure White Paper

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MongoDB on Windows Azure

A 10gen White Paper


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MongoDB on Windows Azure brings the

power of the leading NoSQL database

to Microsofts exible, open, and

scalable cloud.

MongoDB is an open source, document-

oriented database designed with scalability

and developer agility in mind. Windows

Azure is the cloud services operating sys-

tem that provides the development, service

hosting, and service management envi-

ronment for the Azure Services Platform.

Together, MongoDB and Windows Azure

MongoDB on Windows Azure

provide customers the tools to build limit-

lessly scalable applications in the cloud.

This paper begins with an overview of

MongoDB. Next, we describe the two

primary deployment options available on

Microsofts cloud platform, Windows Azure

Virtual Machines and Windows Azure Cloud

Services. Finally, to help those evaluating

deploying MongoDB on Windows Azure,

we outline the pros and cons of the two

deployment options available.


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About MongoDBMongoDB is an open source, document-

oriented database. MongoDB bridges the

gap between key-value stores which are

fast and scalable and relational databas-

es which have rich functionality. Instead

of storing data in tables and rows as one

would with a relational database, MongoDB

stores a binary form of JSON (BSON or

binary JSON documents). An example of a

document is shown in Figure 1.

The document serves as the fundamental

unit within MongoDB (like a row in an

RDBMS); one can add elds (like a column

in an RDBMS), as well as nested elds and

embedded documents. Rather than impos-

ing a at, rigid schema across an entire

table, the schema is implicit in what elds

are used in the documents. Thus, MongoDB

allows developers to have variable schemas

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{

"_id": ObjectId("504e4dd43796b3da50183991"),

"text": "Study Implicates Immune System in Parkinsons Disease Pathogenesis http://bit.ly/duhe4P",

"source": "twitterfeed,

"coordinates": null,

"truncated": false,

"entities": {

"urls": [{

"indices": [

67,

87],

"url": "http://bit.ly/duhe4P",

"expanded_url": null

}],

"hashtags": []

},

"retweeted": false,

"place": null,

"user": {

"friends_count": 780,

"created_at": "Fri Jan 08 17:40:11 +0000 2010", "description": "Latest medical news, articles, and features from Medscape Pathology.",

"time_zone": "Eastern Time (US & Canada)",

"url": "http://www.medscape.com/pathology",

"screen_name": "MedscapePath",

"utc_offset": -18000

},

"favorited": false,

"in_reply_to_user_id": null,

"id": NumberLong("22819397000")

}

Figure 1: Sample JSON Document

across documents and to adapt schemas as

their applications evolve.

Unlike relational databases, MongoDB does

not use SQL syntax. Rather, MongoDB has

a query language based on JSON. It also

has drivers for most modern languages,

such as C#, Java, Ruby, Python, and many

others. MongoDBs exible data model and

support for modern programming languages

simplify development and administration

signicantly.


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MongoDB ArchitectureMongoDBs core capabilities deliver reli-

ability, high availability, high performance,

and scalability.

Replication through replica setsprovides for

high availability and data safety. A replica

setis comprised of one primary node and

some number of secondary nodes (de-

termined by the user). Figure 2 shows an

example replica set, with one primary and

two secondaries (a common deployment

model). By default, the primary node takes

all reads and writes from the application;

the secondaries replicate asynchronously in

the background. If the primary node goes

down for any reason, one of the secondaries

is automatically promoted to primary status

and begins to take all reads and writes.

Replica sets help protect applications fromhardware and data center-related down-

time. Moreover, they make it easy for DBAs

to conduct operational tasks, including

software upgrades and hardware changes.

Figure 2: Replica Sets with MongoDB

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Secondary

Secondary

Application

Read Write

Asynchronous

Replication

Automatic

Leader Election

Primary

Driver

Figure 3: Sharding with MongoDB

Shard A

0...30

Shard B

31...60

Shard C

61...90

Shard N

n...n+30

...

Horizontally Scalable

Sharding enables users to scale horizon-

tally as their data volumes grow and/or as

demands on their data stores grow. A shard

is a subset of the database, kind of like a

partition of the data. In Figure 3, Shard A

contains documents 1-30; Shard B contains

documents 31-60; and so on. One can

choose any key on which to shard the col-

lection (e.g., user name), and MongoDB will

automatically shard the data store based on

this key. One can scale a database in-

nitely using sharding by adding new nodes

to a cluster. When a new node is added,

MongoDB recognizes it and redistributes

the data across the cluster. Because shard-

ing distributes both the actual data and

therefore the load (i.e., trafc), it enables

horizontal scalability as well as high per-

formance.


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An overview of the MongoDB architecture is shown in Figure

4. In a multi-shard environment, the application communi-cates with mongos, an intermediary router that directs reads

and writes to the appropriate shard. Each shard is a replica

set, providing scalability, availability, and performance to

developers.

MongoDB was built for the cloud. Cloud services like Windows

Azure are therefore a natural t for MongoDB. By coupling

MongoDBs easy-to-scale architecture and Azures elastic

cloud capacity, users can quickly and easily build, scale, and

manage their applications.

About Windows Azure Servicesfor MongoDBWindows Azure is Microsofts suite of cloud services, providing

developers on-demand compute and storage to create, host

and manage scalable and available web applications through

Microsoft data centers. When deploying MongoDB to Windows

Azure, users can choose from two deployment options:

Windows Azure Virtual Machines. Windows AzureVirtual Machines (VMs) is Microsofts Infrastructure-as-

a-Service (IaaS) offering. Similar to Amazon Web Services

EC2, Azure VMs give users access to elastic, on-demand

virtual servers. Users can install Windows or Linux on a VM

and congure it based on their own preferences or their

apps specic needs. Users manage the VMs themselves,

including scaling, installing security patches, and ongoing

performance monitoring and management. Azure VMs give

users a relatively signicant degree of control over their

environments, but by the same token require users to take

on the VM management. Note: This service is currently in

preview (beta).

Windows Azure Cloud Services. Windows Azure CloudServices (Worker Roles and Web Roles) is Microsofts

PlatformasaService (PaaS) offering. Similar to Heroku,

Worker Roles provide users with prebuilt, precongured

instances of compute power. In contrast with Azure VMs,

users do not have to congure or manage Azure Worker

Roles. Windows Azure handles the deployment details

from provisioning and load balancing to health monitoring

for continuous availability. This can be helpful to some

users who prefer not to manage their applications at the

infrastructure level, though it restricts the level of control

users have over their environments.

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Application

Replica Set A

0...30

Replica Set B

31...60

Replica Set C

61...90

Replica Set N

n...n+30

...Secondary

Secondary

Primary

Secondary

Secondary

Primary

Secondary

Secondary

Primary

Secondary

Secondary

Primary

Driver

mongos

Figure 4: MongoDB Architecture


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Understanding the Deployment OptionsGiven that MongoDB can be deployed on either Windows

Azure Virtual Machines (IaaS) or Windows Azure Cloud Services

(PaaS), it is important for users to consider the different capa-

bilities and implementation details of each service to deter-

mine which deployment model makes the most sense for their

applications.

Azure Virtual Machines

BASIC SETUP

After being granted access to the preview functionality for

Azure Virtual Machines, users can launch an instance and

install and congure MongoDB on it manually. Alternatively,

users can use the recently released Windows Azure installer for

MongoDB to set up a MongoDB replica set quickly and easily on

Windows Azure VMs.

The installer is built on top of Windows PowerShell and the

Windows Azure command line tool. It contains a number of

deployment scripts. The tool is designed to help users get

single or multi-node MongoDB congurations up and running

quickly. There are only two steps to installing and congur-

ing a MongoDB replica set on Azure VMs. Note: the installer

is designed to run on a users local machine (i.e., not directly

on an Azure VM), and then to deploy output to Windows Azure

VMs. To start , download the publish settings le. Next, run the

installer from the command prompt.

With Azure Virtual Machines, users can create their own VMs or

they can create a VM instance from one of several pre-installed

operating system congurations. Both Windows and Linux are

supported on Azure Virtual Machines. To deploy MongoDB on

Linux, visit the MongoDB wiki (wiki.mongodb.org) for step-by-

step instructions.

PROS AND CONS OF AZURE VIRTUAL MACHINES

The pros and cons of deploying MongoDB on Azure Virtual Ma -

chines are generally consistent with the considerations around

using IaaS more broadly. Overall, Azure Virtual Machines allow

users to ne-tune their deployments but by the same token

require increased operational effort.

The advantages of using MongoDB on Azure Virtual Machines

are as follows:

Increased Control. Users have more control over theirinfrastructural conguration relative to Azure CloudServices. For instance, they can install and congure

services on the OS, dene policies, etc. This consideration

may be important for enterprises that have regimented

policies and processes for IT security and compliance.

OS Choice. Users can use Windows or Linux.

Azure Virtual Machines may not always be the right t for the

following reasons:

Increased Operational Effort. The increased control that Azure

Virtual Machines provide comes with increase effort , as well.

Users must dene and implement their own security measures,

apply patches, and locate instances for fault tolerance. This

consideration may be important for developers that lack expe-

rience managing their own infrastructure or for companies that

dont have the operational bandwidth to devote to managing

this component of the stack.

Beta. The Azure Virtual Machines service is still in

Preview (beta).

Azure Cloud Services

BASIC SETUP

Users can also deploy MongoDB on Azure Cloud Services. To

do so, download the MongoDB Azure Worker Role package,

which is a precongured Worker Role with MongoDB. When

deployed, each replica set member runs as a separate Worker

Role instance; MongoDB data les are stored in Azure Cloud

Drives. For detailed instructions, visit the MongoDB wiki (wiki.

mongodb.org).

PROS AND CONS OF AZURE CLOUD SERVICES

The pros and cons of running MongoDB on Azure Cloud

Services are generally consistent with those of using PaaS in

general, though there are some Azure-specic considerations.

Overall, Windows Azure Cloud Services decreases the opera-

tional burden on users but affords them less control from an

infrastructure conguration standpoint. The advantages ofusing Azure Cloud Services are as follows:

Lower Operational Effort . Microsoft manages OS updatesand security, decreasing the operational burden on the

users.

Built-in Fault Tolerance. When deploying multipleMongoDB worker role instances, Windows Azure

automatically deploys the instances across multiple fault

and update domains to guarantee better uptime.

Secure by Default. Microsoft takes measures to ensure thatworker and web roles are secure. Endpoints on instances

can be enabled for instance-to-instance communication

without making them public. Thus, one can congure

MongoDB to be secure by enabling it only for other roles in

the same deployment.

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PROS CONS

Initial

Administrative

Effort

- Windows only

- Fixed OS

configuration

IaaS

Windows

Azure Virtual

Machines

- Increased operational

effort

- Increased control

- OS choice

- Lower operational effort

- Built-in fault tolerance

- Secure by default

Table 1: Pros and Cons Summary - Windows Azure Virtual Machines and

Windows Azure Cloud Services

By the same token, there are some aspects

of Azure Cloud Services that may be consid-

ered drawbacks:

Windows Only. Worker Roles can only bedeployed with Windows; Linux is not an

option. Fixed OS Confguration. Users cannotcongure the OS, and must therefore

develop applications that run on the

pre-dened machine congurations

available.

Table 1 summarizes the pros and cons of

using Windows Azure Worker Roles and

Windows Azure Virtual Machines.

SummaryMongoDB was built for ease of use, scal-

ability, availability, and performance, and

its quickly becoming an attractive alterna-

tive to relational databases. Windows Azure

provides a exible cloud platform for host-

ing MongoDB, with two deployment models

to choose from. Developers and enterprises

looking at deploying MongoDB on Windows

Azure should consider the pros and cons

discussed here when evaluating which

option is most appropriate for them. We

hope that this paper helps customers better

understand these solutions, how they work,and how to assess them.

To learn more about MongoDB and how

to deploy it in the cloud, or to speak

to a sales representative, please email

[email protected].

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10gen Mongodb Microsoftazure White Paper