Skip to content
    Moz logo Menu open Menu close
    • Products
      • Moz Pro
      • Moz Pro Home
      • Moz Local
      • Moz Local Home
      • STAT
      • Moz API
      • Moz API Home
      • Compare SEO Products
      • Moz Data
    • Free SEO Tools
      • Domain Analysis
      • Keyword Explorer
      • Link Explorer
      • Competitive Research
      • MozBar
      • More Free SEO Tools
    • Learn SEO
      • Beginner's Guide to SEO
      • SEO Learning Center
      • Moz Academy
      • MozCon
      • Webinars, Whitepapers, & Guides
    • Blog
    • Why Moz
      • Digital Marketers
      • Agency Solutions
      • Enterprise Solutions
      • Small Business Solutions
      • The Moz Story
      • New Releases
    • Log in
    • Log out
    • Products
      • Moz Pro

        Your all-in-one suite of SEO essentials.

      • Moz Local

        Raise your local SEO visibility with complete local SEO management.

      • STAT

        SERP tracking and analytics for enterprise SEO experts.

      • Moz API

        Power your SEO with our index of over 44 trillion links.

      • Compare SEO Products

        See which Moz SEO solution best meets your business needs.

      • Moz Data

        Power your SEO strategy & AI models with custom data solutions.

      Track AI Overviews in Keyword Research
      Moz Pro

      Track AI Overviews in Keyword Research

      Try it free!
    • Free SEO Tools
      • Domain Analysis

        Get top competitive SEO metrics like DA, top pages and more.

      • Keyword Explorer

        Find traffic-driving keywords with our 1.25 billion+ keyword index.

      • Link Explorer

        Explore over 40 trillion links for powerful backlink data.

      • Competitive Research

        Uncover valuable insights on your organic search competitors.

      • MozBar

        See top SEO metrics for free as you browse the web.

      • More Free SEO Tools

        Explore all the free SEO tools Moz has to offer.

      NEW Keyword Suggestions by Topic
      Moz Pro

      NEW Keyword Suggestions by Topic

      Learn more
    • Learn SEO
      • Beginner's Guide to SEO

        The #1 most popular introduction to SEO, trusted by millions.

      • SEO Learning Center

        Broaden your knowledge with SEO resources for all skill levels.

      • On-Demand Webinars

        Learn modern SEO best practices from industry experts.

      • How-To Guides

        Step-by-step guides to search success from the authority on SEO.

      • Moz Academy

        Upskill and get certified with on-demand courses & certifications.

      • MozCon

        Save on Early Bird tickets and join us in London or New York City

      Unlock flexible pricing & new endpoints
      Moz API

      Unlock flexible pricing & new endpoints

      Find your plan
    • Blog
    • Why Moz
      • Digital Marketers

        Simplify SEO tasks to save time and grow your traffic.

      • Small Business Solutions

        Uncover insights to make smarter marketing decisions in less time.

      • Agency Solutions

        Earn & keep valuable clients with unparalleled data & insights.

      • Enterprise Solutions

        Gain a competitive edge in the ever-changing world of search.

      • The Moz Story

        Moz was the first & remains the most trusted SEO company.

      • New Releases

        Get the scoop on the latest and greatest from Moz.

      Surface actionable competitive intel
      New Feature

      Surface actionable competitive intel

      Learn More
    • Log in
      • Moz Pro
      • Moz Local
      • Moz Local Dashboard
      • Moz API
      • Moz API Dashboard
      • Moz Academy
    • Avatar
      • Moz Home
      • Notifications
      • Account & Billing
      • Manage Users
      • Community Profile
      • My Q&A
      • My Videos
      • Log Out

    The Moz Q&A Forum

    • Forum
    • Questions
    • Users
    • Ask the Community

    Welcome to the Q&A Forum

    Browse the forum for helpful insights and fresh discussions about all things SEO.

    1. Home
    2. SEO Tactics
    3. Intermediate & Advanced SEO
    4. How can I prevent duplicate pages being indexed because of load balancer (hosting)?

    Moz Q&A is closed.

    After more than 13 years, and tens of thousands of questions, Moz Q&A closed on 12th December 2024. Whilst we’re not completely removing the content - many posts will still be possible to view - we have locked both new posts and new replies. More details here.

    How can I prevent duplicate pages being indexed because of load balancer (hosting)?

    Intermediate & Advanced SEO
    2
    2
    2090
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as question
    Log in to reply
    This topic has been deleted. Only users with question management privileges can see it.
    • iam-sold
      iam-sold last edited by

      The site that I am optimising has a problem with duplicate pages being indexed as a result of the load balancer (which is required and set up by the hosting company).

      The load balancer passes the site through to 2 different URLs:

      • www.domain.com
      • www2.domain.com

      Some how, Google have indexed 2 of the same URLs (which I was obviously hoping they wouldn't) - the first on www and the second on www2.

      The hosting is a mirror image of each other (www and www2), meaning I can't upload a robots.txt to the root of www2.domain.com disallowing all. Also, I can't add a canonical script into the website header of www2.domain.com pointing the individual URLs through to www.domain.com etc.

      Any suggestions as to how I can resolve this issue would be greatly appreciated!

      1 Reply Last reply Reply Quote 0
      • customerparadigm.com
        customerparadigm.com last edited by

        There are two ways to handle load balancing, and it appears that your hosting company / server company chose to use the DNS round-robin routing option.

        According to the Wikipedia page on load balancing:
        http://en.wikipedia.org/wiki/Load_balancing_(computing)

        "Load balancing usually involves dedicated software or hardware, such as a multilayer switch or a Domain Name System server process."

        Round Robin DNS Load Balancing: Basically you use the DNS routing system to handle requests. When someone visits your site, 50% of the people are routed to www.domain.com, and 50% are routed to ww1.domain.com. Both sites contain the same identical content; it's the URLs that are slightly different. Sometimes the domains are the same; but you have different IP addresses for www.domain.com.

        Advantages: you don't need a dedicated load balancing piece of software or hardware, so it's less expensive.
        Disadvantages: this technique exposes the individual web servers to the end user seeing the site. You can also suffer from duplicate content penalties, too. Finally, if you are relying on the round robin DNS system for load balancing, and a DNS server or one of the Web servers goes down, there's not an easy fail-over (as many DNS records are cached).

        More about Round Robin DNS: http://en.wikipedia.org/wiki/Round-robin_DNS

        Hardware / Software Load Balancer:
        In this case, your DNS zone file tells the end user to go to one IP address when they type in www.domain.com. The hardware or software load balancer then sees the request, and then hands off the content to one of the web servers in a cluster.

        Advantages: No duplicate content penalty; to the end user, they just see one web server and not individual sub-domains (www.domain.com and ww1.domain.com). A load balancer can also cache specific items like a CSS page, so the load on the Web server is even more minimal.

        Disadvantages: You're introducing another piece of hardware or software (i.e. more cost); this piece could also be a single point of failure into the mix. You need someone to figure out how to set this up and make sure it all works.

        More on this type of Load Balancing: http://en.wikipedia.org/wiki/Load_balancing_(computing)#Internet-based_services

        Load balancing can get complicated as soon as you have databases involved, but with a good design, multiple front end Web servers can talk to one single backend database server. The goal would be to cache as much content as possible as "static" elements, using caching systems like Varnish, that essentially turn database-driven pages into static, old-school HTML pages. And then only when someone needs to save something from the database (i.e. making a purchase on an eCommerce site), the system then interacts with it.

        My recommendation:
        (1) Move from the Round Robin Robin DNS to a hardware or software load balancer.

        (2) If that isn't an easy solution, implement the Round Robin DNS solution to use identical A records for each server.

        For example, you might have identical entries in your DNS zone files for both DNS servers:

        NS1.domain.com:

        www.domain.com A 69.94.15.10

        NS2.domain.com:
        www.domain.com A 75.64.18.12

        This should at least eliminate your duplicate content issue, but you still do have a few disadvantages (described above). This also could lead to server issues, as the servers might be confused if they are the authoritative ones.

        And if both servers are sending email, pay special attention to your SPF record, to make sure that you are allowing both IP addresses to be able to send email. (This is often overlooked.)

        Hope this is helpful!
        -- Jeff

        1 Reply Last reply Reply Quote 2
        • 1 / 1
        • First post
          Last post

        Got a burning SEO question?

        Subscribe to Moz Pro to gain full access to Q&A, answer questions, and ask your own.


        Start my free trial


        Browse Questions

        Explore more categories

        • Moz Tools

          Chat with the community about the Moz tools.

        • SEO Tactics

          Discuss the SEO process with fellow marketers

        • Community

          Discuss industry events, jobs, and news!

        • Digital Marketing

          Chat about tactics outside of SEO

        • Research & Trends

          Dive into research and trends in the search industry.

        • Support

          Connect on product support and feature requests.

        • See all categories

        Related Questions

        • KenSchaefer

          No Index thousands of thin content pages?

          Hello all! I'm working on a site that features a service marketed to community leaders that allows the citizens of that community log 311 type issues such as potholes, broken streetlights, etc.  The "marketing" front of the site is 10-12 pages of content to be optimized for the community leader searchers however, as you can imagine there are thousands and thousands of pages of one or two line complaints such as, "There is a pothole on Main St. and 3rd." These complaint pages are not about the service, and I'm thinking not helpful to my end goal of gaining awareness of the service through search for the community leaders.  Community leaders are searching for "311 request service", not "potholes on main street". Should all of these "complaint" pages be NOINDEX'd?   What if there are a number of quality links pointing to the complaint pages?  Do I have to worry about losing Domain Authority if I do NOINDEX them? Thanks for any input. Ken

          Intermediate & Advanced SEO | | KenSchaefer
          0
        • Andy.Drinkwater

          How long to re-index a page after being blocked

          Morning all! I am doing some research at the moment and am trying to find out, just roughly, how long you have ever had to wait to have a page re-indexed by Google. For this purpose, say you had blocked a page via meta noindex or disallowed access by robots.txt, and then opened it back up. No right or wrong answers, just after a few numbers 🙂 Cheers, -Andy

          Intermediate & Advanced SEO | | Andy.Drinkwater
          0
        • Bryggselv.no

          How can I make a list of all URLs indexed by Google?

          I started working for this eCommerce site 2 months ago, and my SEO site audit revealed a massive spider trap. The site should have been 3500-ish pages, but Google has over 30K pages in its index. I'm trying to find a effective way of making a list of all URLs indexed by Google. Anyone? (I basically want to build a sitemap with all the indexed spider trap URLs, then set up 301 on those, then ping Google with the "defective" sitemap so they can see what the site really looks like and remove those URLs, shrinking the site back to around 3500 pages)

          Intermediate & Advanced SEO | | Bryggselv.no
          0
        • Chemometec

          Do I need to re-index the page after editing URL?

          Hi, I had to edit some of the URLs. But, google is still showing my old URL in search results for certain keywords, which ofc get 404. By crawling with ScremingFrog it gets me 301 'page not found' and still giving old URLs. Why is that? And do I need to re-index pages with new URLs? Is 'fetch as Google' enough to do that or any other advice? Thanks a lot, hope the topic will help to someone else too. Dusan

          Intermediate & Advanced SEO | | Chemometec
          0
        • SeoMartin1

          Whats the best way to remove search indexed pages on magento?

          A new client ( aqmp.com.br/ )call me yestarday and she told me since they moved on magento they droped down more than US$ 20.000 in sales revenue ( monthly)... I´ve just checked the webmaster tool and I´ve just discovered the number of crawled pages went from 3.260 to 75.000 since magento started... magento is creating lots of pages with queries like search and filters. Example: http://aqmp.com.br/acessorios/lencos.html http://aqmp.com.br/acessorios/lencos.html?mode=grid http://aqmp.com.br/acessorios/lencos.html?dir=desc&order=name Add a instruction on robots.txt is the best way to remove unnecessary pages of the search engine?

          Intermediate & Advanced SEO | | SeoMartin1
          0
        • fablau

          Are pages with a canonical tag indexed?

          Hello here, here are my questions for you related to the canonical tag: 1. If I put online a new webpage with a canonical tag pointing to a different page, will this new page be indexed by Google and will I be able to find it in the index? 2. If instead I apply the canonical tag to a page already in the index, will this page be removed from the index? Thank you in advance for any insights! Fabrizio

          Intermediate & Advanced SEO | | fablau
          0
        • TauriU

          Google is indexing wordpress attachment pages

          Hey, I have a bit of a problem/issue what is freaking me out a bit. I hope you can help me. If i do site:www.somesitename.com search in Google i see that Google is indexing my attachment pages. I want to redirect attachment URL's to parent post and stop google from indexing them. I have used different redirect plugins in hope that i can fix it myself but plugins don't work. I get a error:"too many redirects occurred trying to open www.somesitename.com/?attachment_id=1982 ". Do i need to change something in my attachment.php fail? Any idea what is causing this problem? get_header(); ?> /* Run the loop to output the attachment. * If you want to overload this in a child theme then include a file * called loop-attachment.php and that will be used instead. */ get_template_part( 'loop', 'attachment' ); ?>

          Intermediate & Advanced SEO | | TauriU
          0
        • CommercePundit

          Number of Indexed Pages are Continuously Going Down

          I am working on online retail stores. Initially, Google have indexed 10K+ pages of my website. I have checked number of indexed page before one week and pages were 8K+. Today, number of indexed pages are 7680. I can't understand why should it happen and How can fix it? I want to index maximum pages of my website.

          Intermediate & Advanced SEO | | CommercePundit
          0

        Get started with Moz Pro!

        Unlock the power of advanced SEO tools and data-driven insights.

        Start my free trial
        Products
        • Moz Pro
        • Moz Local
        • Moz API
        • Moz Data
        • STAT
        • Product Updates
        Moz Solutions
        • SMB Solutions
        • Agency Solutions
        • Enterprise Solutions
        • Digital Marketers
        Free SEO Tools
        • Domain Authority Checker
        • Link Explorer
        • Keyword Explorer
        • Competitive Research
        • Brand Authority Checker
        • Local Citation Checker
        • MozBar Extension
        • MozCast
        Resources
        • Blog
        • SEO Learning Center
        • Help Hub
        • Beginner's Guide to SEO
        • How-to Guides
        • Moz Academy
        • API Docs
        About Moz
        • About
        • Team
        • Careers
        • Contact
        Why Moz
        • Case Studies
        • Testimonials
        Get Involved
        • Become an Affiliate
        • MozCon
        • Webinars
        • Practical Marketer Series
        • MozPod
        Connect with us

        Contact the Help team

        Join our newsletter
        Moz logo
        © 2021 - 2025 SEOMoz, Inc., a Ziff Davis company. All rights reserved. Moz is a registered trademark of SEOMoz, Inc.
        • Accessibility
        • Terms of Use
        • Privacy

        Looks like your connection to Moz was lost, please wait while we try to reconnect.