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How to Boost Performance Of Your Rails App Using DynamoDB And Memcached

Posted on December 8, 2021 by Anurag Pattnaik

With the increasing number of apps going live on the web, it’s becoming common to see that they use multiple servers. This is mainly due to scalability and availability purposes. But, these types of applications are also often not as responsive as they should be. Using a simple gem called DynamoDB and Memcached will allow you to achieve higher performance in your Rails app. Let me explain,

What is Memcached

Memcached is a high performance, free and open source distributed memory caching system used to speeding up dynamic web applications by alleviating database load. Memcached is simple yet powerful. Its simple design promotes quick deployment, ease of development, and solves many problems facing large data caches.

It is used for speeding up dynamic web applications by reducing database load. In other words, every time a database request is made it adds additional load to the server. Memcached reduces that load by storing data objects in dynamic memory (think of it as short-term memory for applications). Memcached stores data based on key-values for small arbitrary strings.

How does Memcached work?

Memcached is comprised of four main components

Client software – Which is given a list of available Memcached servers
A client-based hashing algorithm – Chooses a server based on the “key”
Server software – Stores values and their keys into an internal hash table
LRU – Determines when to throw out old data or reuse memory

Each item is comprised of a key, expiration time, and raw data.

At a high-level Memcached works as follows:

The client requests a piece of data which Memcached checks to see if it is stored in cache.
There are two possible outcomes here:
1. If the data is stored in cache: return the data from Memcached (no need to check the database).
2. If the data isn’t stored in cache: query the database, retrieve the data, and subsequently store it in Memcached.
Whenever information is changed or the expiry value of an item has expired, Memcached updates its cache to ensure fresh content is delivered to the client.

A few important points about Memcached architecture include:

Data is only sent to one server.
Servers don’t share data.
Servers keep values in RAM. If RAM runs out the oldest value is discarded.

What is DynamoDB

Amazon DynamoDB is a fully managed NoSQL database service that provides fast and predictable performance with seamless scalability. With DynamoDB, you can create database tables that can store and retrieve any amount of data and serve any level of request traffic. You can scale up or scale down your tables’ throughput capacity without downtime or performance degradation.

DynamoDB is a particularly good fit for the following use cases

Applications with large amounts of data and strict latency requirements
Server less applications using AWS Lambda
Data sets with simple, known access patterns

Installing Memcached

There are a few ways you can install Memcached. Depending on which system you’re using, the method will vary. As outlined on the official Memcached Installation Wiki, installation from a package is simple.

Using Memcached with DynamoDB in Rails

Memcached is a quick in-memory protest reserving framework that can make Rails run much quicker with not very many changes. Memcached will work on any database used in Rails application.

When the table is small and request volume is low this isn’t much of an issue, but as your database and user volume grow, these can impact the performance of your application. In such cases Memcached plays an important role to reduce the database load by caching the request object in memory.

To use Memcached in Rails app, follow the below steps

Install dalli gem

[code language=”css”]gem ‘dalli'[/code]

Add “dalli” gem to your gem file and install it.

Development/Production file

[code language=”css”]config.cache_store = :dalli_store</em><em> </em><em>config.action_controller.perform_caching = true[/code]

Add the above lines in your development.rb or production.rb file as per the requirement

Add Memcached in your method

[code language=”css”]search_query = "user_id = :user_id AND is_approved = :is_approved"
search_param = {":user_id" => params[:user_id], ":is_approved" => ‘t’}
all_games = Rails.cache.fetch(‘all_lists’, expires_in: 2.minutes)
{
do_scan(Article.table_name,search_query,search_param)
}[/code]

The above query syntax is an example of combination of Memcached and DynamoDB. In this example once the query executed and the result will store in the “all_list” key of the Memcached and expire after 2 minutes automatically.

Conclusion:

DynamoDB and Memcached is a powerful combination for your Rails app. If you’re looking to improve the performance of your Rails application, this may be the solution for you.

DynamoDB and Memcached involves storing information in an external database, which can be retrieved with a single call. This will allow you to avoid the constant querying of data from your application’s memory.

There are many benefits to this gem, but most importantly, increased response time for your application. Faster response times mean less downtime and more satisfied customers.

You have rails application but don’t know how to maximize the performance with DynamoDB and Memcached. Andolasoft has experienced rails developer who has good hands on DynamoDB and Memcached. So fell free to discuss about your project. Book a free consultation

Supercharge your Rails app development with “Metric_fu”

Posted on October 8, 2013 by Srikant M.

Why we need Metric_fu?

Sometimes we are unaware of unknown complexities in our rails code and it gets messy. Moreover, it reduces application performance, scalability and maintainability.

What is Metric_fu?

Metric_fu is a set of rake tasks and compilation of several different tools that provides reports. This show which parts of your rails code might need extra work. It uses the following built-in tasks to create a series of reports.

Rcov – Measures test coverage
Flog – Measures code complexity
Saikuro – Measures cyclomatic complexity
Flay – Finds duplication (both copy/paste and structural)
Reek – Spots code smells
Roodi – Finds lots of general problems
Churn – Identifies files that changes too often
Rails best practices – code matric tool
Cane -code quality threshold violations
HotSpot– Meta analysis of your metrics to find hotspots in the code

Benefits of Metric_fu

You can measure the complexity of rails code
Creates a “hit list” of most complex methods
Reveals hidden issues like bugs and other complexities
Examine worst offenders
Refactoring complex methods
Creates smaller, easier to understand methods

Step#1

Add ‘metric_fu’ gem to your gem file

gem "metric_fu"

Run “bundle install”

Metric_fu will install several other dependencies unless they are already present.
These include Flay, Flog, Rcov, Reek, Facets and Roodi.

Run following command to generate the metrics

rake metrics:all

It will generate a metric of your code in the temp/matric_fu repository,
it uses a number of other open source project to generate the metric.

Code analysis isn’t an exact science and none of the tools shown are perfect in themselves.
So they should all be used as an aid to help you find complex areas of your code and supercharge Rails app development.

Unveiling FeedZirra: Simplifying Feed Parsing in Your Rails Application

Posted on June 19, 2013 by Srikant M.

What is a Feed?

A feed is a data format which is used to provide frequent updates and latest contents to the users. A feed has no particular type; it could be news, latest technology, game, gadgets, sports etc. These feeds can be easily parsed into your Rails application to make it more useful for the users. The feed is build up with XML and has particular format type.

What is Feedzirra?

“Feedzirra” on the other hand is a feed library built on Ruby that is designed to get and update a number of feeds as fast as possible. This includes using “libcurl-multi” through the “curb” gem for faster http gets, and “libxml” through “nokogiri” and “sax-machine” for faster parsing.

Suppose you need to add some updated information to your Rails application from other feed site like ‘feedburner’, in such cases you can easily work it out by using the gem “feedzirra”.

Here are the steps to use ‘feedzirra’ in your Rails application.

Step-1

Add the gem ‘feedzirra’ in to your gem file.

[sourcecode language=”plain”]gem ‘feedzirra'[/sourcecode]

Run ‘bundle install’ to install the gem along with its dependencies.

Step-2

Modify your controller where you are fetching the feeds.

[sourcecode language=”plain”]require ‘feedzirra'[/sourcecode]

Step-3

Now, write the following code in your method in order to parse feeds from an external site.

[sourcecode language=”plain”]feed =Feedzirra::Feed.fetch_and_parse("http://feeds.feedburner.com/TechCrunch/gaming")
@entry = feed.entries
[/sourcecode]

Note: Here we are parsing the feeds from ‘feedburne’r site with updated information on gaming news.

Step-4

Now, open your view section and write the following code snippet to display the information regarding the feeds.

[sourcecode language=”plain”]<ul>
<%@entry.each do |t|%>
<li>
<%= link_to "#{t.title}", "#{t.url}",:target => "_blank" %>
<%=t.author%>
<%=t.content%>
<%=t.published%>
<%=t.categories%>
</li>
<%end%>
</ul>
[/sourcecode]

Note: The above code will display the feed title, author name, content, published date and category type. Clicking the feed title, will launch a new tab in browser and display the detail information of that feed.

Step-5

You can also fetch multiple feeds by writing the following code.

[sourcecode language=”plain”]feed_urls = ["http://feeds.feedburner.com/PaulDixExplainsNothing", "http://feeds.feedburner.com/trottercashion"]
feeds = Feedzirra::Feed.fetch_and_parse(feed_urls)
[/sourcecode]

Conclusion:

The FeedZirra gem empowers Rails developers to seamlessly integrate feed parsing capabilities into their applications.

Are you looking for a Ruby on Rails developer

Whether you’re building a news aggregator, a blog reader, or a content recommendation system, FeedZirra simplifies the process of retrieving and presenting timely content from various sources.

By harnessing the power of FeedZirra, you can enhance user engagement, keep your app’s content fresh, and deliver a more dynamic user experience.

Collecting Contacts Using Cardmagic-Contacts Pplug-in in Rails 2.3.8

Posted on December 18, 2012 by Jay

Cardmagic-Contacts is a rails plug-in which provides an interface to fetch contact list information from various email providers including Hotmail, AOL, Gmail, Plaxo, Yahoo and many more.

This example narrates how to extract contact list using Rails 2.3.8 and cardmagic-contacts plug-in

Step#1

Download the plug-in by running the command below to store the plug-in in the folder “vendor/plug-ins”

Windows

ruby script/plugin install git://github.com/cardmagic/contacts

Linux

ruby script/plugin http://github.com/cardmagic/contacts

Step#2

Write down the following code on the top of the controller class

require 'contacts'

Step#3

Pass the required gmail/yahoo/hotmail/AOL login & password from view

<div>
 
<div style="margin-left:25px;" >Invite <img src="../images/yahoo.JPG">Yahoo
 
Friends </div>
 
<div style="margin-left:25px;">Yahoo Email: <input type="text" name="email"
 
id="yahoo_email_id"></div>
<div style="margin-left:25px;">Password:   <input type="password"
 
name="email"  id="yahoo_pwd_id"></div>
 
<div style="margin-left:122px;margin-top:20px;"><input type="button"
 
value="Login" name="btn_submit" id="btn_submit" ></div>
 
</div>

Step#4

Create an action to fetch the list of contacts for a specific email id

def grab_contacts #Grab gmail contacts @gmail_contacts=Contacts::Gmail.new(login, password).contacts #or @gmail_contacts=Contacts.new(:gmail, login, password).contacts #Grab yahoo contacts @yahoo_contacts = Contacts::Yahoo.new(login, password).contacts #or @yahoo_contacts = Contacts.new(:yahoo, login, password).contacts #Grab hotmail contacts @hotmail_contacts =Contacts::Hotmail.new(login, password).contacts #or @hotmail_contacts = Contacts.new(:hotmail, login, password).contacts end

Step#5

Here is also alternate method to get the contacts by providing email_id and password

any_mail = Contacts.guess(login, password).contacts

The “Contacts.guess” method will automatically concatenate the entire
address book from each of the successful logins. If the login and password is
working with multiple email accounts then it will grab the contacts from all accounts.

Step#6

Display the friends list in your view page

<table>
<th>
<td >Friends Name</td>
<td >Friends Email</td>
</th>
<tr>
<% @gmail_contacts.each do |contact| %>
<td><%=contact[0]%></td>
<td><%=contact[1]%></td>
<% end %>
</tr>
</table>

What is the Importance of Filters in Rails

Posted on December 13, 2012 by Jay

In Ruby on Rails development, filters play a vital role. They are the methods executed ‘before’, ‘after’ or ‘around’ a controller action.

For example, one filter might check to see if the user has the credentials to access that particular controller or action.

Filters are inherited, so if you set a filter on ‘ApplicationController’, it would run on every controller in your application.

Below is an example to explain how a filter can be used to restrict a non-logged in user to access specified actions in a controller

Step#1

In Application controller write the following block of code according to the requirement.

def user_login_required
 if !session[:username]
 flash[:notice] = "Oops you need to login!"
 redirect_to :controller => "user_sessions", :action => "new"
 end
end

Step#2

Now write the before_filter block in the controller you want to restrict the not registered users. You can also restrict particular actions of a controller by writing the action name.

class UsersController < ApplicationController
 before_filter :user_login_required, :only => [:profile]
 def profile
 [Your code block goes here]
 end
end

In the above block the ‘before_filter’ restrict the not registered user to access
the profile page and redirect them to login page. We can also restrict multiple
actions by writing like this

before_filter :user_login_required, :only => [:profile,:edit]

In this case the filter is applied to only these two methods of a particular controller.

before_filter :user_login_required, :except => [:index,:show]

In this case the filter is applied to all other actions except index and show
action of a particular controller.

If you write the before_filter block in the “ApplicationController” then the
filter will be applied to all the controllers.

Planning anything on Ruby on Rails? Talk to Andolasoft’s experts to get a clearer idea.

How to implement Multiple Database(DB) Connection in Rails3

Posted on December 3, 2012 by Jay

In some scenarios, we need data from an external database to execute in different applications. Here, we need a bridge that will connect these two different databases.

In Ruby on Rails, this can be achieved through ActiveRecord’s establish_connection().

Following are the steps to create a rails application which uses multiple databases, where the existing database and the external database will work simultaneously.

Let’s say there are two different rails applications say “myapp” and “remoteapp” where “myapp” depends upon “remoteapp” user table.

Step#1

Edit the ‘database.yml‘ file for the ‘myapp‘ project
Add a new connection for ‘remoteapp‘ as below:

# Connection name, it will be used to connect from myapp
connect_remote:
adapter: mysql2
username: user_name             # username of the remoteapp database
password: password             # password of the remoteapp database
pool: 5
database: remoteapp_db_name    # database name of the remoteapp
host: www.remoteapphost.com      # host name of the db

Step#2

In models folder create a new file called user.rb if it is not already there. Write below code to establish connection with remote app’s database.

class User < ActiveRecord::Base
establish_connection("connect_remote")
end

Here use the connection name defined in the database.yml file in the establish_connection() method.
Like this you can create models to connect with remote databases.
Step#3

It will give you the flexibility for managing users’ data of remote app’s database like it is present in the myapp database.
Use the normal way to get data from the user’s table like

User.all                   #To get all the records
User.find(id)              #To get required record

Here you can also insert or update data in users table by normal way as it is
present in myapp application

#insert new record
user = User.new params[:user]
user.save
 
#update existing record
user = User.find params[:id]
user.update_attributes(params[:user])

Tag: Rails App

How to Boost Performance Of Your Rails App Using DynamoDB And Memcached

What is Memcached

How does Memcached work?

What is DynamoDB

Installing Memcached

Using Memcached with DynamoDB in Rails

Install dalli gem

Development/Production file

Conclusion:

Supercharge your Rails app development with “Metric_fu”

What is Metric_fu?

Benefits of Metric_fu

Unveiling FeedZirra: Simplifying Feed Parsing in Your Rails Application

What is a Feed?

What is Feedzirra?

Step-1

Step-2

Step-3

Step-4

Step-5

Conclusion:

Are you looking for a Ruby on Rails developer

Related Questions

Collecting Contacts Using Cardmagic-Contacts Pplug-in in Rails 2.3.8

Step#1

Step#2

Step#3

Step#4

Step#5

What is the Importance of Filters in Rails

How to implement Multiple Database(DB) Connection in Rails3