Bobcares

Understanding and Fixing 404 Errors in HAProxy

by | Mar 10, 2025

Learn more about the errors in HAProxy and how to fix them. Our HAProxy Support team is here to help you with your questions and concerns.

Understanding and Fixing 404 Errors in HAProxy

Understanding and Fixing 404 Errors in HAProxyDid you know that a 404 error in HAProxy is an HTTP status code that tells us that the requested web page or resource cannot be found on the server?

Unlike network errors, a 404 indicates that the client successfully communicated with the server, but the server couldn’t locate the specific content requested.

Today, we will discuss the impacts, causes, and solutions to these errors.

Impacts of 404 Errors in HAProxy

404 errors don’t just affect users! They also impact server performance, load balancing, and monitoring. Let’s take a look at this:

  • Disrupts accurate server health monitoring.
  • It can cause incorrect server status reporting.
  • This may lead to unnecessary server marking as unavailable.
  • Interferes with proper server routing.
  • Prevents traffic distribution.
  • Creates unpredictable backend server selection.
  • Indicates potential security misconfigurations.
  • It may block legitimate user requests.
  • Causes service interruptions.
  • Incorrect host header handling.
  • Misconfigured proxy settings.
  • Disrupts expected request-response mechanisms.
  • Generates misleading health check logs.
  • Complicates troubleshooting.
  • Creates blind spots in system monitoring.
  • Gives the impression of service unavailability.
  • Reduces user confidence in the application.
  • Risks loss of user engagement and trust.

Common Causes and How to Fix Them

1. Mistyped URLs

Spelling mistakes in URLs prevent the server from locating the correct page.

Click here for the Solution.
  • Double-check URL spelling.
  • Implement client-side URL validation.
  • Provide user-friendly error messages.
  • Carefully review each character in the URL.
  • Client-Side Validation Example:

    function validateURL(url) {
    const urlPattern = /^(https?:\/\/)?([\da-z\.-]+)\.([a-z\.]{2,6})([\/\w \.-]*)*\/?$/;
    return urlPattern.test(url);
    }

  • Display friendly error messages.
  • Offer “Did you mean?” suggestions.
  • Provide quick redirect options.

2. Moved or Deleted Pages

Pages moved or deleted without proper redirects.

Click here for the Solution.
  • Implement 301 (permanent) or 302 (temporary) redirects.
  • Maintain an updated sitemap.
  • Add redirect rules to `.htaccess`.

Here is a 301 Redirect Example:

Redirect 301 /old-page /new-page

Furthermore, step up sitemap management by conducting quarterly sitemap audits, using automated link tracking, etc.

3. DNS Issues

Incorrect domain pointing or DNS propagation delays.

Click here for the Solution.
  • Verify DNS configuration.
  • Check domain registration and expiration.
  • Use tools like `nslookup` or `dig`.

4. Broken or Dead Links

Internal or external links pointing to non-existent pages.

Click here for the Solution.
  • Regularly audit website links.
  • Use link-checking tools like Google Search Console.
  • Implement custom 404 error pages with helpful navigation.

Here is a custom 404-page example:


<div class="404-page">
<h1>Page Not Found</h1>
<p>Suggested links:</p>
<ul>
<li><a href="/homepage">Home</a></li>
<li><a href="/sitemap">Sitemap</a></li>
</ul>
</div>

5. File Permissions

Incorrect file permissions blocking page access.

Click here for the Solution.
  • Reset permissions (644 for files, 755 for folders).
  • Adjust via the hosting control panel or command line.
  • Ensure proper read/write/execute rights.
  • Manually adjust permissions in the file manager.

Here are the Linux Permission commands:


# File permissions
chmod 644 filename
# Directory permissions
chmod 755 directory

6. Corrupted .htaccess Files

Misconfigured `.htaccess` rules.

Click here for the Solution.
  • Backup and recreate `.htaccess`.
  • Use standard configurations (like for WordPress).
  • Verify syntax and rules.

We can backup & reset .htaccess with this command:

cp .htaccess .htaccess_backup

Here is the WordPress Default .htaccess:


<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
</IfModule>

Prevention Strategies

  • Use custom error pages for clear, user-friendly messaging.
  • Also, configure `errorfiles` for different HTTP status codes.
  • Implement conditional error handling based on the host.
  • Furthermore, maintain a comprehensive link management system.
  • Implement robust redirect strategies.
  • Additionally, audit website structure regularly.
  • Use URL canonicalization.
  • Also, apply permanent redirects for moved content.
  • Keep sitemaps updated.

[Need assistance with a different issue? Our team is available 24/7.]

Conclusion

404 errors in HAProxy go beyond simple “page not found” messages. They may impact server health, user experience, and site performance. We need to resolve the causes of the error as soon as possible to keep the web applications running smoothly.

In brief, our Support Experts demonstrated how to fix a 404 error in HAProxy.

0 Comments

Submit a Comment

Your email address will not be published. Required fields are marked *

Never again lose customers to poor
server speed! Let us help you.

Privacy Preference Center

Necessary

Necessary cookies help make a website usable by enabling basic functions like page navigation and access to secure areas of the website. The website cannot function properly without these cookies.

PHPSESSID - Preserves user session state across page requests.

gdpr[consent_types] - Used to store user consents.

gdpr[allowed_cookies] - Used to store user allowed cookies.

PHPSESSID, gdpr[consent_types], gdpr[allowed_cookies]
PHPSESSID
WHMCSpKDlPzh2chML

Statistics

Statistic cookies help website owners to understand how visitors interact with websites by collecting and reporting information anonymously.

_ga - Preserves user session state across page requests.

_gat - Used by Google Analytics to throttle request rate

_gid - Registers a unique ID that is used to generate statistical data on how you use the website.

smartlookCookie - Used to collect user device and location information of the site visitors to improve the websites User Experience.

_ga, _gat, _gid
_ga, _gat, _gid
smartlookCookie
_clck, _clsk, CLID, ANONCHK, MR, MUID, SM

Marketing

Marketing cookies are used to track visitors across websites. The intention is to display ads that are relevant and engaging for the individual user and thereby more valuable for publishers and third party advertisers.

IDE - Used by Google DoubleClick to register and report the website user's actions after viewing or clicking one of the advertiser's ads with the purpose of measuring the efficacy of an ad and to present targeted ads to the user.

test_cookie - Used to check if the user's browser supports cookies.

1P_JAR - Google cookie. These cookies are used to collect website statistics and track conversion rates.

NID - Registers a unique ID that identifies a returning user's device. The ID is used for serving ads that are most relevant to the user.

DV - Google ad personalisation

_reb2bgeo - The visitor's geographical location

_reb2bloaded - Whether or not the script loaded for the visitor

_reb2bref - The referring URL for the visit

_reb2bsessionID - The visitor's RB2B session ID

_reb2buid - The visitor's RB2B user ID

IDE, test_cookie, 1P_JAR, NID, DV, NID
IDE, test_cookie
1P_JAR, NID, DV
NID
hblid
_reb2bgeo, _reb2bloaded, _reb2bref, _reb2bsessionID, _reb2buid

Security

These are essential site cookies, used by the google reCAPTCHA. These cookies use an unique identifier to verify if a visitor is human or a bot.

SID, APISID, HSID, NID, PREF
SID, APISID, HSID, NID, PREF