5 Common Server Setups for Your Web Application _ DigitalOcean

8/11/2019 5 Common Server Setups for Your Web Application _ DigitalOcean

1/12

6/6/2014 5 Common Server Setups For Your Web Application | DigitalOcean

https://www.digitalocean.com/community/articles/5-common-server-setups-for-your-web-application

Sign UpLog In

Community

Tutorials

Questions

Projects

Explore

IRC

Before you continue...

You are about to enter a community-supported IRC chat. DigitalOcean is not responsible for its content. If you

require immediate assistance, please open a support ticket.

Continue to IRC Chat

Search the Community

May 30, 2014

Beginner

5 Common Server Setups For Your Web

Application

Tagged In: Getting Started, Lamp Stack, Scaling, Caching

Introduction

When deciding which server architecture to use for your environment, there are many factors to consider, such as

performance, scalability, availability, reliability, cost, and ease of management.

Here is a list of commonly used server setups, with a short description of each, including pros and cons. Keep in

mind that all of theconcepts covered here can be used in various combinations with one another, and that every

environment has different requirements, so there is no single, correct configuration.

1. Everything On One Server

The entire environment resides on a single server. For a typical web application, that would include the web

server, application server, and database server. A common variation of this setup is a LAMP stack, which stands

for Linux, Apache, MySQL, and PHP, on a single server.

Use Case: Good for setting up an application quickly, as it is the simplest setup possible, but it offers little in the

way of scalability and component isolation.

Contents

1. Everything On One Server

2. Separate Database Server

3. Load Balancer (Reverse Proxy)

4. HTTP Accelerator (Caching Reverse Proxy)

5. Master-Slave Database Replication

Example: Combining the Concepts

Conclusion
https://www.digitalocean.com/community/projectshttps://www.digitalocean.com/community/questionshttps://www.digitalocean.com/community/https://www.digitalocean.com/community/projectshttps://www.digitalocean.com/community/articleshttps://www.digitalocean.com/community/tags/cachinghttps://www.digitalocean.com/community/tags/scalinghttps://www.digitalocean.com/community/tags/lamp-stackhttps://www.digitalocean.com/community/tags/getting-startedhttp://webchat.freenode.net/?channels=digitalocean&uio=d4https://cloud.digitalocean.com/supporthttps://www.digitalocean.com/community/tagshttps://www.digitalocean.com/community/projectshttps://www.digitalocean.com/community/questionshttps://www.digitalocean.com/community/articleshttps://www.digitalocean.com/community/https://cloud.digitalocean.com/loginhttps://cloud.digitalocean.com/registrations/new


2/12


https://www.digitalocean.com/community/articles/5-common-server-setups-for-your-web-application 2

Pros:

Simple

Cons:

Application and database contend for the same server resources (CPU, Memory, I/O, etc.) which, aside

from possible poor performance, can make it difficult to determine the source (application or database) ofpoor performance

Not readily horizontally scalable

Related Tutorials:

How To Install LAMP On Ubuntu 14.04

2. Separate Database Server

The database management system (DBMS) can be separated from the rest of the environment to eliminate theresource contention between the application and the database, and to increase security by removing the database

from the DMZ, or public internet.

Use Case: Good for setting up an application quickly, but keeps application and database from fighting over the

same system resources.

Pros:
https://www.digitalocean.com/community/articles/how-to-install-linux-apache-mysql-php-lamp-stack-on-ubuntu-14-04


3/12



Application and database tiers do not contend for the same server resources (CPU, Memory, I/O, etc.)

You may vertically scale each tier separately, by adding more resources to whichever server needs

increased capacity

Depending on your setup, it may increase security by removing your database from the DMZ

Cons:

Slightly more complex setup than single server

Performance issues can arise if the network connection between the two servers is high-latency (i.e. the

servers are geographically distant from each other), or the bandwidth is too low for the amount of data

being transferred

Related Tutorials:

How To Set Up a Remote Database to Optimize Site Performance with MySQL

How to Migrate A MySQL Database To A New Server On Ubuntu 14.04

3. Load Balancer (Reverse Proxy)Load balancers can be added to a server environment to improve performance and reliability by distributing the

workload across multiple servers. If one of the servers that is load balanced fails, the other servers will handle the

incoming traffic until the failed server becomes healthy again. It can also be used to serve multiple applications

through the same domain and port, by using a layer 7 (application layer) reverse proxy.

Examples of software capable of reverse proxy load balancing: HAProxy, Nginx, and Varnish.

Use Case: Useful in an environment that requires scaling by adding more servers, also known as horizontal

scaling.

Pros:

Enables horizontal scaling, i.e. environment capacity can be scaled by adding more servers to it
https://www.digitalocean.com/community/articles/how-to-migrate-a-mysql-database-to-a-new-server-on-ubuntu-14-04https://www.digitalocean.com/community/articles/how-to-set-up-a-remote-database-to-optimize-site-performance-with-mysql


4/12



Can protect against DDOS attacks by limiting client connections to a sensible amount and frequency

Cons:

The load balancer can become a performance bottleneck if it does not have enough resources, or if it is

configured poorly

Can introduce complexities that require additional consideration, such as where to perform SSL

termination and how to handle applications that require sticky sessions

Related Tutorials:

An Introduction to HAProxy and Load Balancing Concepts

How To Use HAProxy As A Layer 4 Load Balancer for WordPress Application Servers

How To Use HAProxy As A Layer 7 Load Balancer For WordPress and Nginx

4. HTTP Accelerator (Caching Reverse Proxy)

An HTTP accelerator, or caching HTTP reverse proxy, can be used to reduce the time it takes to serve contentto a user through a variety of techniques. The main technique employed with an HTTP accelerator is caching

responses from a web or application server in memory, so future requests for the same content can be served

quickly, with less unnecessary interaction with the web or application servers.

Examples of software capable of HTTP acceleration: Varnish, Squid, Nginx.

Use Case: Useful in an environment with content-heavy dynamic web applications, or with many commonly

accessed files.

Pros:

Increase site performance by reducing CPU load on web server, through caching and compression,

thereby increasing user capacity

Can be used as a reverse proxy load balancer

Some caching software can protect against DDOS attacks

Cons:
https://www.digitalocean.com/community/articles/how-to-use-haproxy-as-a-layer-7-load-balancer-for-wordpress-and-nginx-on-ubuntu-14-04https://www.digitalocean.com/community/articles/how-to-use-haproxy-as-a-layer-4-load-balancer-for-wordpress-application-servers-on-ubuntu-14-04https://www.digitalocean.com/community/articles/an-introduction-to-haproxy-and-load-balancing-concepts


5/12



Requires tuning to get best performance out of it

If the cache-hit rate is low, it could reduce performance

Related Tutorials:

How To Install Wordpress, Nginx, PHP, and Varnish on Ubuntu 12.04

How To Configure a Clustered Web Server with Varnish and Nginx

How To Configure Varnish for Drupal with Apache on Debian and Ubuntu

5. Master-Slave Database Replication

One way to improve performance of a database system that performs many reads compared to writes, such as a

CMS, is to use master-slave database replication. Master-slave replication requires a master and one or more

slave nodes. In this setup, all updates are sent to the master node and reads can be distributed across all nodes.

Use Case: Good for increasing the read performance for the database tier of an application.

Here is an example of a master-slave replication setup, with a single slave node:

Pros:

Improves database read performance by spreading reads across slaves

Can improve write performance by using master exclusively for updates (it spends no time serving readrequests)

Cons:

The application accessing the database must have a mechanism to determine which database nodes it

should send update and read requests to

Updates to slaves are asynchronous, so there is a chance that their contents could be out of date

If the master fails, no updates can be performed on the database until the issue is corrected

Does not have built-in failover in case of failure of master node
https://www.digitalocean.com/community/articles/how-to-configure-varnish-for-drupal-with-apache-on-debian-and-ubuntuhttps://www.digitalocean.com/community/articles/how-to-configure-a-clustered-web-server-with-varnish-and-nginx-on-ubuntu-13-10https://www.digitalocean.com/community/articles/how-to-install-wordpress-nginx-php-and-varnish-on-ubuntu-12-04


6/12


7/12



If the user requests static content:

1. The load balancer checks cache-backend to see if the requested content is cached (cache-hit) or not

(cache-miss)

2. If cache-hit: return the requested content to the load balancer and jump to Step 7.If cache-miss: the

cache server forwards the request to app-backend, through the load balancer

3. The load balancer forwards the request through to app-backend

4. app-backend reads from the database then returns requested content to the load balancer

5. The load balancer forwards the response to cache-backend

6. cache-backend caches the contentthen returns it to the load balancer

7. The load balancer returns requested data to the user

This environment still has two single points of failure (load balancer and master database server), but it provides

the all of the other reliability and performance benefits that were described in each section above.

Conclusion

Now that you are familiar with some basic server setups, you should have a good idea of what kind of setup youwould use for your own application(s). If you are working on improving your own environment, remember that

an iterative process is best to avoid introducing too many complexities too quickly.

Let us know of any setups you recommend or would like to learn more about in the comments below!

By Mitchell Anicas

Related Articles

How To Migrate Droplets Using SnapshotsHow the IPTables Firewall Works

How To Install Opigno on Debian 7 with Git and Drush

How To Write a Simple Shell Script on a VPS (Part 3)

How To Write a Simple Shell Script on a VPS (Part 2)

How To Enable User and Group Quotas

How To Use cd, pwd, and ls to Explore the File System on a Linux Server

How To Transition from Media Temple to DigitalOcean's Control Panel

Share this TutorialTweet 444

Share 87 344Vote

Try this tutorial on an SSD cloud server.

Includes 512MB RAM, 20GB SSD Disk, and 1TB Transfer for $5/mo! Learn more
https://www.digitalocean.com/pricinghttps://www.digitalocean.com/community/articles/how-to-transition-from-media-temple-to-digitalocean-s-control-panelhttps://www.digitalocean.com/community/articles/how-to-use-cd-pwd-and-ls-to-explore-the-file-system-on-a-linux-serverhttps://www.digitalocean.com/community/articles/how-to-enable-user-and-group-quotashttps://www.digitalocean.com/community/articles/how-to-write-a-simple-shell-script-on-a-vps-part-2https://www.digitalocean.com/community/articles/how-to-write-a-simple-shell-script-on-a-vps-part-3https://www.digitalocean.com/community/articles/how-to-install-opigno-on-debian-7-with-git-and-drushhttps://www.digitalocean.com/community/articles/how-the-iptables-firewall-workshttps://www.digitalocean.com/community/articles/how-to-migrate-droplets-using-snapshotshttps://news.ycombinator.com/item?id=7833594http://twitter.com/search?q=https%3A%2F%2Fwww.digitalocean.com%2Fcommunity%2Farticles%2F5-common-server-setups-for-your-web-applicationhttps://twitter.com/intent/tweet?original_referer=https%3A%2F%2Fwww.digitalocean.com%2Fcommunity%2Farticles%2F5-common-server-setups-for-your-web-application&text=5%20Common%20Server%20Setups%20For%20Your%20Web%20Application%20%7C%20DigitalOcean&tw_p=tweetbutton&url=https%3A%2F%2Fwww.digitalocean.com%2Fcommunity%2Farticles%2F5-common-server-setups-for-your-web-application


8/12



Create an account or login:

Email

Password

Get Started!

14 Comments

Write Tutorial

kylemclaren 3 days

Well explained, thanks!

Reply

dlazerka 3 days

And Google App Engine gives all of that for free, plus 1. Master-master replication, which gives you

almost infinite horizontal scaling. 2. Automatically replicates your data over datacenters/continents, so even

whole datacenter failure won't make your unavaliable. 3. Serves static content (HTML, CSS, JS, images)without even touching your server, from Google's distributed Content Delivery Network. 4. Secures

HTTPS requests automatically, no need to obtain/install/manage SSL certificates. 5. Many more. And all

of that automatically, you don't worry how it works inside.

Reply

Abimael Martell 3 days

But GAP only supports some languages... you can't compare

Reply

nguyenhstephen 3 days
https://www.digitalocean.com/community/get-paid-to-write


9/12



#5 could be it's own article. lovely article though.

Reply

davidneubauer 3 days

Awesome article, can you write another one that includes Snort level security threat detection? ;)

Reply

adamkdean 3 days

@dlazerka whilst we're at it, why don't we suck all of the fun out of the web development as well, and just

go for a prebuilt system? Recommending people use something out of the tin rather than learning how itworks is setting them up for failure. Live a little, learn a little.

Reply

cerivera 3 days

awesome post.

Reply

kiru42 3 days

What happens when a load balancer fails? any alternative of common setups?

Reply

app 3 days

Great Post

Reply


10/12



aglamb 3 days

incredible article! well served!

Reply

garethpoole 3 days

excellent summary, thanks a lot

Reply

kamlesh.kumar 3 days

It's very nice article thanks

Reply

dan 2 days

very good article. I have always wondered though what do people do about the single point of failure of a

load balancer? In all these pictures (and in my own setups as well) if the load balancer fails, what then?

Reply

Mitchell Anicas 2 days

@dan / @kiru42: The easiest way to avoid having the load balancer be a single point of failure is to set up

an active/passive HAProxy pair. This would require two HAProxy servers and a virtual/floating IP that can

move between the two servers. The active HAProxy server would handle all of the requests unless it went

down, at which point the passive HAProxy server would take over the requests. This is a high availability

(HA) setup. DigitalOcean, similarly to many other hosting providers, does not currently support floating IP

addresses. Some people suggest using round robin DNS to workaround not having floating IP addresses,

but it is not a true HA setup for a variety of reasons. I do not recommend it because there are situations

where it can actually decrease your availability. If you would like to experiment with it anyway, here is a


11/12



tutorial: https://www.digitalocean.com/community/articles/how-to-configure-dns-round-robin-load-

balancing-for-high-availability

Reply

Leave a Comment

Leave a comment...

Create an account or login:

Email

Password

Submit Comment

Copyright 2014

DigitalOcean Inc.

Proudly Made in NY

Terms, Privacy, & CopyrightSecurity

Product

Pricing

Features

Customers

One-Click Apps

API

Company
https://api.digitalocean.com/https://www.digitalocean.com/features/one-click-apps/https://www.digitalocean.com/customers/https://www.digitalocean.com/features/https://www.digitalocean.com/pricing/https://www.digitalocean.com/legal/terms/http://nytm.org/made-in-nyc/


12/12


About Us

Blog

Jobs

Press

Logos & Badges

Events

Contact

Help

Knowledgebase

Getting Started

Feedback

Referral Program

Network Status

Community

Dashboard

Overview

Tutorials

Questions

Projects

Tutorial Suggestions

Get Paid to Write

Connect

Twitter

Facebook

LinkedIn

Google+

Instagram

1,789,910 Droplets Launched
http://instagram.com/thedigitaloceanhttps://plus.google.com/+Digitalocean/postshttp://www.linkedin.com/company/digitaloceanhttps://www.facebook.com/DigitalOceanCloudHostinghttps://twitter.com/digitaloceanhttps://www.digitalocean.com/community/get-paid-to-writehttps://www.digitalocean.com/community/articles/digitalocean-community-article-suggestions-and-ideashttps://www.digitalocean.com/community/projectshttps://www.digitalocean.com/community/questionshttps://www.digitalocean.com/community/articleshttps://www.digitalocean.com/community/overviewhttps://www.digitalocean.com/community/http://www.digitaloceanstatus.com/https://www.digitalocean.com/referral-program/http://digitalocean.uservoice.com/forums/136585-digital-oceanhttps://www.digitalocean.com/help/getting-started/https://www.digitalocean.com/help/https://www.digitalocean.com/company/contact/https://www.digitalocean.com/company/events/https://www.digitalocean.com/company/logos-and-badges/https://www.digitalocean.com/company/press/https://www.digitalocean.com/company/careers/https://www.digitalocean.com/company/blog/https://www.digitalocean.com/company/about/

Documents

5 Common Server Setups for Your Web Application _ DigitalOcean