Article Network

Hosting Workflow Applications in Microsoft Windows Workflow Foundation 4.0

by Andrew Zhu | October 2010 | Cookbooks Enterprise Articles Microsoft

In this article, by Andrew Zhu, author of Microsoft Windows Workflow Foundation 4.0 we will cover:

  • Hosting a workflow service in IIS7
  • Hosting workflow in ASP.NET
  • Hosting workflow in WPF
  • Hosting workflow in a Windows Form
Read Hosting Workflow Applications in Microsoft Windows Workflow Foundation 4.0 in full

Hooking into native events

by Matt Gifford | January 2013 | Cookbooks Open Source

When developing for mobile devices, we can create feature-rich applications that harness the functionality of the native processes and systems.

The devices themselves provide us with built-in controls and user interface elements in the form of native buttons, to which we can apply methods and functions.

We can also make use of the hidden events and manage how our applications work when placed in the background on the device or alter states depending on network connectivity.

In this article by Matt Gifford, author of PhoneGap Mobile Application Development Cookbook, will introduce you to some of the native events available through the PhoneGap API, and how we can implement them into applications.

In this article, we will cover:

  • Pausing your application

  • Resuming your application

  • Displaying the status of the device battery levels

  • Making use of the native search button

  • Displaying network connection status

  • Creating a custom submenu

Read Hooking into native events in full

Home Security by BeagleBone

by Bill Pretty | December 2013 | Open Source

This article by Bill Pretty, author of Building a Home Security System with BeagleBone, tells us about the use of BeagleBone for building home security system.

Read Home Security by BeagleBone in full

Highlights of Greenplum

by Sunila Gollapudi | October 2013 | Enterprise Articles

In this article written by Sunila Gollapudi, the author of the book Getting Started with Greenplum for Big Data Analytics explains the various components of Greenplum UAP as well as the features and advantages of Greenplum Database.

Read Highlights of Greenplum in full

Highcharts

by Cyril Grandjean | August 2013 | Content Management Open Source

In this article created by Cyril Grandjean, the author of Instant Highcharts, we will create a line chart with a time axis and two Y axes. We will also customize the chart by customizing the tool tip and by adding the possibility to zoom inside the chart.

Read Highcharts in full

High Availability: Oracle 11g R1 R2 Real Application Clusters (RAC)

by Ben Prusinski Syed Jaffar Hussain | May 2011 | Enterprise Articles Oracle

In this article by Ben Prusinski and Syed Jaffer Hussain, authors of Oracle 11g R1/R2 Real Applications Clusters Essentials, we will discuss how Oracle 11g RAC provides you with mission-critical options for minimizing outages and downtime as well as how RAC fits into the overall scheme for maintenance of a comprehensive disaster recovery and business continuity policy. In this article, we will provide you with an introduction to the high availability concepts and solutions that are workable for Oracle 11g. In summary, we will discuss the following topics:

  • High availability concepts
  • Fault-tolerant systems and high availability
  • High availability solutions for Oracle 11g R1 and 11g R2 Real Application Clusters (RAC)
Read High Availability: Oracle 11g R1 R2 Real Application Clusters (RAC) in full

Hibernate Types

by Ahmad Seddighi | November 2009 | Java Open Source

In this article by Ahmad Seddighi, we will discuss the Hibernate types. We will see how Hibernate provides built-in types that map to common database types. We'll also see how Hibernate allows us to implement and use custom types when these built-in types do not satisfy the application's requirements, or when we want to change the default behavior of a built-in type. As you will see, you can easily implement a custom-type class and then use it in the same way as a built-in one.

Read Hibernate Types in full

Hello OpenCL

by Koushik Bhattacharyya Ravishankar Somasundaram | December 2013 | Open Source

In this article by Ravishekhar Banger and Koushik Bhattacharyya, authors of the book OpenCL Programming by Example, we will learn the basic concepts of OpenCL. Parallel Computing has been extensively researched over the past few decades and had been the key research interest at many universities. Parallel Computing uses multiple processors or computers working together on a common algorithm or task. Due to the constraints in the available memory, performance of a single computing unit, and also the need to complete a task quickly, various parallel computing frameworks have been defined. All computers are parallel these days, even your handheld mobiles are multicore platforms and each of these parallel computers uses a parallel computing framework of their choice. Let's define Parallel Computing.

Read Hello OpenCL in full

HDFS and MapReduce

by Rohit Menon | July 2014 |

In this article, written by Rohit Menon, the author of the book Cloudera Administration Handbook, we will dive deeper into the two major components of Apache Hadoop—HDFS and MapReduce, and will cover the following topics:

  • Essentials of Hadoop Distributed File System

  • The read/write operational flow in HDFS

  • Exploring HDFS commands

  • Getting acquainted with MapReduce

Read HDFS and MapReduce in full

HBase Administration, Performance Tuning, Hadoop

by Yifeng Jiang | August 2012 | Cookbooks MySQL Content Management Open Source Oracle PHP
<p>Performance is one of the most interesting characteristics of an HBase cluster's behavior. It is a challenging operation for administrators, because performance tuning requires deep understanding of not only HBase but also of Hadoop, <b>Java Virtual Machine Garbage Collection(JVM GC)</b>, and important tuning parameters of an operating system.</p> <p>The structure of a typical HBase cluster is shown in the following diagram:</p> <p style="text-align: center;"><img src="/sites/default/files/Article-Images/7140_08_01.png" border="0" /></p> <p>There are several components in the cluster&mdash;the ZooKeeper cluster, the HBase master node , region servers , the <b>Hadoop Distributed File System(HDFS)</b> and the HBase client.</p> <p>The ZooKeeper cluster acts as a coordination service for the entire HBase cluster, handling master selection, root region server lookup, node registration, and so on. The master node does not do heavy tasks. Its job includes region allocation and failover, log splitting, and load balancing. Region servers hold the actual regions; they handle I/O requests to the hosting regions, flush the in-memory data store (MemStore) to HDFS, and split and compact regions. HDFS is the place where HBase stores its data files (StoreFile) and write ahead logs (WAL). We usually have an HBase region server running on the same machine as the HDFS DataNode, but it is not mandatory.</p> <p>The HBase client provides APIs to access the HBase cluster. To communicate with the cluster, clients need to find the region server holding a specific row key range; this is called region lookups. HBase has two system tables to support region lookups&mdash;the <i>-ROOT-</i> table and the <i>.META.</i> table.</p> <p>The -ROOT-table is used to refer to regions in the .META.table, while the .META.table holds references to all user regions. First, the clients query ZooKeeper to find the -ROOT-table location (the region server where it is deployed); they then query the -ROOT-table, and subsequently the .META.table, to find the region server holding a specific region. Clients also cache region locations to avoid querying ZooKeeper, -ROOT-, and .META.tables every time. With this background knowledge, we will describe how to tune HBase to gain better performance, in this article.</p> <p>Besides HBase itself, other tuning points include Hadoop configurations, the JVM garbage collection settings, and the OS kernel parameters. These are as important as tuning HBase itself. We will also include recipes to tune these configurations, in this article.</p> <p>In this article, by <b>Yifeng Jiang</b>, author of <a href="http://www.packtpub.com/hbase-administration-for-optimum-database-performance-cookbook/book" target="_blank"><b>HBase Administration Cookbook</b></a>, we will cover:</p> <ul> <li>Setting up Hadoop to spread disk I/O</li> <li>Using a network topology script to make the Hadoop rack-aware</li> <li>Mounting disks with noatimeand nodiratime</li> <li>Setting vm.swappinessto 0 to avoid swap</li> <li>Java GC and HBase heap settings</li> <li>Using compression</li> <li>Managing compactions</li> <li>Managing a region split</li> </ul> Read HBase Administration, Performance Tuning, Hadoop in full

HBase Administration, Performance Tuning

by Yifeng Jiang | August 2012 | Cookbooks MySQL Content Management Open Source Oracle PHP

Performance is one of the most interesting characteristics of an HBase cluster's behavior. It is a challenging operation for administrators, because performance tuning requires deep understanding of not only HBase but also of Hadoop, Java Virtual Machine Garbage Collection (JVM GC), and important tuning parameters of an operating system.

The structure of a typical HBase cluster is shown in the following diagram:

There are several components in the cluster—the ZooKeeper cluster, the HBase master node , region servers, the Hadoop Distributed File System(HDFS) and the HBase client.

The ZooKeeper cluster acts as a coordination service for the entire HBase cluster, handling master selection, root region server lookup, node registration, and so on. The master node does not do heavy tasks. Its job includes region allocation and failover, log splitting, and load balancing. Region servers hold the actual regions; they handle I/O requests to the hosting regions, flush the in-memory data store (MemStore) to HDFS, and split and compact regions. HDFS is the place where HBase stores its data files (StoreFile) and write ahead logs (WAL). We usually have an HBase region server running on the same machine as the HDFS DataNode, but it is not mandatory.

The HBase client provides APIs to access the HBase cluster. To communicate with the cluster, clients need to find the region server holding a specific row key range; this is called region lookups. HBase has two system tables to support region lookups—the -ROOT- table and the .META. table.

The -ROOT-table is used to refer to regions in the .META.table, while the .META.table holds references to all user regions. First, the clients query ZooKeeper to find the -ROOT-table location (the region server where it is deployed); they then query the -ROOT-table, and subsequently the .META.table, to find the region server holding a specific region. Clients also cache region locations to avoid querying ZooKeeper, -ROOT-, and .META.tables every time. With this background knowledge, we will describe how to tune HBase to gain better performance, in this article.

Besides HBase itself, other tuning points include Hadoop configurations, the JVM garbage collection settings, and the OS kernel parameters. These are as important as tuning HBase itself. We will also include recipes to tune these configurations, in this article.

In this article, by Yifeng Jiang, author of HBase Administration Cookbook, we will cover:

  • Setting up Hadoop to spread disk I/O
  • Using a network topology script to make the Hadoop rack-aware
  • Mounting disks with noatimeand nodiratime
  • Setting vm.swappinessto 0 to avoid swap
  • Java GC and HBase heap settings
  • Using compression
  • Managing compactions
  • Managing a region split
Read HBase Administration, Performance Tuning in full

haXe 2: Using Templates

by Benjamin Dasnois | July 2011 | Open Source Web Development

haXe is the universal programming language which is completely cross-platform and provides a standard library that remains the same—regardless of platform. Templates are a very useful feature of haXe. They help the developer with his job of presenting data to the user by making it easy to repeat some parts of a view (or page) and by allowing some branching depending on data.

In this article by Benjamin Dasnois, author of haXe 2 Beginner's Guide: RAW, we will cover templating by talking about:

  • The included haxe.Template class
  • The syntax used by the templating system
  • How data is passed to the templating system
  • How a template can execute some actions

So if you are ready, let's go!

Read haXe 2: Using Templates in full

haXe 2: The Dynamic Type and Properties

by Benjamin Dasnois | July 2011 | Open Source Web Development

haXe is the universal programming language which is completely cross-platform and provides a standard library that remains the same—regardless of platform. The Dynamic type is a type with a special behavior. Through this article by Benjamin Dasnois, author of haXe 2 Beginner's Guide, you will learn why, how you can use it, and also what you should pay attention to. Understanding the Dynamic type is a key point in mastering haXe.

Specifically, we will:

  • Use Dynamic variables
  • Learn about Dynamic's pitfalls
  • Learn about the parameterized Dynamic class
  • Implement Dynamic in a class
  • Learn about the use of properties in classes
  • Implement properties in classes

Let's get started.

Read haXe 2: The Dynamic Type and Properties in full

Hardware configuration

by Marco Schwartz | July 2014 | Open Source

This article by Marco Schwartz, the author of the book Arduino Home Automation Projects, explores the hardware configuration required to build wireless XBee motion detectors.

Read Hardware configuration in full

Hands-on Tutorial on EJB 3.1 Security

by Richard M. Reese | June 2011 | Cookbooks Enterprise Articles Java

This article by Richard Reese, author of EJB 3.1 Cookbook, covers the process of handling security using annotations. The relationship between the support provided by the server and the roles used by an application is also examined. By the end of this article we will be:

  • Creating the SecurityApplication
  • Configuring the server to handle security
  • Understanding and declaring roles
  • Controlling security using declarations
  • Propagating identity
Read Hands-on Tutorial on EJB 3.1 Security in full

Hands-on Tutorial for Getting Started with Amazon SimpleDB

by Prabhakar Chaganti Rich Helms | May 2010 | Enterprise Articles Java PHP Web Development

With Amazon SimpleDB you can scale your application's database on the cloud. In this article by Prabhakar Chaganti and Rich Helms, authors of Amazon SimpleDB Developer Guide, we going to sign up for an AWS account, download and install the necessary libraries, and create little code snippets for exploring SimpleDB. We will introduce the libraries as well as the SimpleDB Firefox plugin for manipulating SimpleDB. We will also examine the two methods for accessing SimpleDB: SOAP and ReST. For PHP users we will introduce the PHP sample library. You can install the samples on your PHP5 server so that you can try the samples as you read about them.

In this article we will:

  • Set up an AWS account
  • Enable SimpleDB service for the account
  • Install and set up libraries for Java, PHP, and Python
  • Illustrate several SimpleDB operations using these libraries
Read Hands-on Tutorial for Getting Started with Amazon SimpleDB in full

Handling the DOM in Dart

by Dzenan Ridjanovic Ivo Balbaert | December 2013 | Web Development

This article is written by Ivo Balbaert and Dzenan Ridjanovic, the authors of the book Learning Dart.

Read Handling the DOM in Dart in full

Handling sessions and users

by Ron DuPlain | August 2013 | Open Source Web Development

This article by, Ron DuPlain, the author of Instant Flask Web Development, explains how to keep users logged in for on-going requests after authentication. Since HTTP is stateless, we need to track some data across requests with a session.

Read Handling sessions and users in full

Handling Invalid Survey Submissions with Django

by Karen M. Tracey | April 2010 | Content Management Open Source Web Development

In this article by Karen M. Tracey, author of the book Django 1.1 Testing and Debugging, we will see what happens when an invalid survey is submitted.

Read Handling Invalid Survey Submissions with Django in full

Handling Authentication

by Josephus Callaars | December 2013 | Cookbooks Open Source Web Development

In this article by Josephus Callaars, author of Zend Framework 2 Cookbook, we will cover:

  • Understanding Authentication methods
  • Setting up a simple database Authentication

In this article we will talk about the different methods of authentication and we will show you some examples on how to authenticate and how to create your own authentication method.

Read Handling Authentication in full
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