Logo

Navigation
  • Home
  • Services
    • ERP Solutions
    • Implementation Solutions
    • Support and Maintenance Solutions
    • Custom Solutions
    • Upgrade Solutions
    • Training and Mentoring
    • Web Solutions
    • Production Support
    • Architecture Designing
    • Independent Validation and Testing Services
    • Infrastructure Management
  • Expertise
    • Microsoft Development Expertise
    • Mobile Development
    • SQL Server Database and BI
    • SAP BI, SAP Hana, SAP BO
    • Oracle and BI
    • Oracle RAC
  • Technical Training
    • Learn Data Management
      • Business Intelligence
      • Data Mining
      • Data Modeling
      • Data Warehousing
      • Disaster Recovery
    • Learn Concepts
      • Application Development
      • Client Server
      • Cloud Computing Tutorials
      • Cluster Computing
      • CRM Tutorial
      • EDI Tutorials
      • ERP Tutorials
      • NLP
      • OOPS
      • Concepts
      • SOA Tutorial
      • Supply Chain
      • Technology Trends
      • UML
      • Virtualization
      • Web 2.0
    • Learn Java
      • JavaScript Tutorial
      • JSP Tutorials
      • J2EE
    • Learn Microsoft
      • MSAS
      • ASP.NET
      • ASP.NET 2.0
      • C Sharp
      • MS Project Training
      • Silverlight
      • SQL Server 2005
      • VB.NET 2005
    • Learn Networking
      • Networking
      • Wireless
    • Learn Oracle
      • Oracle 10g
      • PL/SQL
      • Oracle 11g Tutorials
      • Oracle 9i
      • Oracle Apps
    • Learn Programming
      • Ajax Tutorial
      • C Language
      • C++ Tutorials
      • CSS Tutorial
      • CSS3 Tutorial
      • JavaScript Tutorial
      • jQuery Tutorial
      • MainFrame
      • PHP Tutorial
      • VBScript Tutorial
      • XML Tutorial
    • Learn Software Testing
      • Software Testing Types
      • SQA
      • Testing
  • Career Training
    • Career Improvement
      • Career Articles
      • Certification Articles
      • Conflict Management
      • Core Skills
      • Decision Making
      • Entrepreneurship
      • Goal Setting
      • Life Skills
      • Performance Development
      • Personal Excellence
      • Personality Development
      • Problem Solving
      • Relationship Management
      • Self Confidence
      • Self Supervision
      • Social Networking
      • Strategic Planning
      • Time Management
    • Education Help
      • Career Tracks
      • Essay Writing
      • Internship Tips
      • Online Education
      • Scholarships
      • Student Loans
    • Managerial Skills
      • Business Communication
      • Business Networking
      • Facilitator Skills
      • Managing Change
      • Marketing Management
      • Meeting Management
      • Process Management
      • Project Management
      • Project Management Life Cycle
      • Project Management Process
      • Project Risk Management
      • Relationship Management
      • Task Management
      • Team Building
      • Virtual Team Management
    • Essential Life Skills
      • Anger Management
      • Anxiety Management
      • Attitude Development
      • Coaching and Mentoring
      • Emotional Intelligence
      • Stress Management
      • Positive Thinking
    • Communication Skills
      • Conversation Skills
      • Cross Culture Competence
      • English Vocabulary
      • Listening Skills
      • Public Speaking Skills
      • Questioning Skills
    • Soft Skills
      • Assertive Skills
      • Influence Skills
      • Leadership Skills
      • Memory Skills
      • People Skills
      • Presentation Skills
    • Finding a Job
      • Etiquette Tips
      • Group Discussions
      • HR Interviews
      • Interview Notes
      • Job Search Tips
      • Resume Tips
      • Sample Resumes
 

High Availability Clustering

By Exforsys | on September 28, 2009 |
Cluster Computing

The trend for most businesses is to provide their services or sell their products online. By tapping the internet, they would be able to expand their customer base not only in their physical location but globally as well. Other businesses that can’t provide their services or sell their products online still use the power of the internet to provide additional information to their prospective customers.

The data, products and services they provide have to be available to their customers 24/7. A downtime for businesses means loss of precious customers and destruction of company image. A website or an online store is basically the face of the business to its customers and unreliability will easily translate to the company’s image.

But maintaining these services to prevent any downtime is difficult when only a single computer handles the requests and processes. For that reason a number of computers have to be clustered to be part of larger component that will assure availability no matter what. Aside from simply connecting them together, this form of clustering assures availability of the functions even if one of the nodes fails to work.

This form of clustering is referred to as High Availability Clustering. Each component or node has the ability to provide the needed function so that it can easily take over when one of the nodes fails. The nodes are often referred to as “redundant” since each of them mirrors each node’s functionality. HA is also called as “failover clustering” as the design assures stability.

Forms of HA Clustering

HA Clustering could be differentiated based on the behavior of the nodes.

The most common form of HA clustering is the active/active configuration. In this type of HA clustering the nodes are programmed to share the workload. However, when one node fails to function, the workload of the failed node will be distributed to other nodes until the failed node is fixed.

Next is the active/passive configuration. The nodes in this configuration all have redundant functions wherein they will take over the primary node in case any problem arises. Basically, only a few nodes will be functioning while others are just back-ups.

The N+1 is considered an active/passive configuration – with a twist. The active nodes share the same workload while there is one node that has the capability of doing everything. However, this type of node is not actively used and will only be tapped to replace the node that failed to work.

N+M could be considered as the more expensive version of N+1. Instead of another node to replace the failed node, a standby server is utilized. M refers to “more” servers which will help in node balancing.

When HA clustering uses N to 1 node configuration, the “extra” node is configured to become universally adaptable but only to a certain extent. N + 1 replaces the failed node while N to 1 is only a temporary configuration.

The N to N configuration is almost the same as active/active configuration. However, an extra node is provided for every failed node to return to the original configuration without going into standby mode.

Configuration Requirements

Although there are different forms of HA configurations, there are general requirements in HA to ensure its success.

• Ease of Start/Stop Operation – this could be manual or through a program but what’s important is that there should be an operation that will immediately stop a node if a problem is noticed.

• Availability of Storage Area Network – this is to ensure data availability for all nodes.

• Ability to Save State – the HA configuration should have the ability to continuously save the state of cluster so that the latest state could be implemented when a node is implemented. This also ensures that the entire network will keep the data even if it crashes.

More than Just Data/Function

High Availability clustering is not just about shared data and functions. Although the main function of HA clustering is to ensure the data is available for the users and function continues to work, hardware configurations should also be shared. Cable connections and power sharing should also be implemented. Without these physical connections, HA clustering will never function or fail to ensure consistent efficiency as more nodes will fail to work.

« « Infrastructure Consideration in Clustering
Compute Clusters and Grid Computing » »

Author Description

Avatar

Editorial Team at Exforsys is a team of IT Consulting and Training team led by Chandra Vennapoosa.

Free Training

RSSSubscribe 394 Followers
  • Popular
  • Recent
  • Clustering Applications

    September 17, 2009 - 0 Comment
  • Cluster Supercomputer

    October 3, 2009 - 0 Comment
  • Virtual Machine Clustering

    September 20, 2009 - 0 Comment
  • Clusters – Monitoring and Measurement

    September 18, 2009 - 0 Comment
  • Load Balancing Clustering

    September 25, 2009 - 0 Comment
  • GPU Clusters

    September 21, 2009 - 0 Comment
  • Clustering Security

    September 22, 2009 - 0 Comment
  • Clustering on P2P

    September 24, 2009 - 0 Comment
  • Compute Clusters and Grid Computing

    September 29, 2009 - 0 Comment
  • Infrastructure Consideration in Clustering

    September 27, 2009 - 0 Comment
  • Cluster Supercomputer

    October 3, 2009 - 0 Comment
  • Clustering through Server Farms

    October 1, 2009 - 0 Comment
  • Two-Node Clusters

    September 30, 2009 - 0 Comment
  • Compute Clusters and Grid Computing

    September 29, 2009 - 0 Comment
  • Infrastructure Consideration in Clustering

    September 27, 2009 - 0 Comment
  • Load Balancing Clustering

    September 25, 2009 - 0 Comment
  • Clustering on P2P

    September 24, 2009 - 0 Comment
  • Clustering Security

    September 22, 2009 - 0 Comment
  • GPU Clusters

    September 21, 2009 - 0 Comment
  • Virtual Machine Clustering

    September 20, 2009 - 0 Comment

Exforsys e-Newsletter

ebook
 

Related Articles

  • Cluster Supercomputer
  • Clustering through Server Farms
  • Two-Node Clusters
  • Compute Clusters and Grid Computing
  • Infrastructure Consideration in Clustering

Latest Articles

  • Project Management Techniques
  • Product Development Best Practices
  • Importance of Quality Data Management
  • How to Maximize Quality Assurance
  • Utilizing Effective Quality Assurance Strategies
  • Sitemap
  • Privacy Policy
  • DMCA
  • Trademark Information
  • Contact Us
© 2023. All Rights Reserved.IT Training and Consulting
This website uses cookies to improve your experience. We'll assume you're ok with this, but you can opt-out if you wish.AcceptReject Read More
Privacy & Cookies Policy

Privacy Overview

This website uses cookies to improve your experience while you navigate through the website. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. We also use third-party cookies that help us analyze and understand how you use this website. These cookies will be stored in your browser only with your consent. You also have the option to opt-out of these cookies. But opting out of some of these cookies may affect your browsing experience.
Necessary
Always Enabled
Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information.
Non-necessary
Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. It is mandatory to procure user consent prior to running these cookies on your website.
SAVE & ACCEPT