Google Offers Guidance on Diagnosing Multi-Domain Crawling Issues

Google Search Advocate, John Mueller, recently shared valuable insights on diagnosing widespread crawling issues, offering guidance that could help webmasters and site owners troubleshoot similar problems in the future.

The advice was prompted by a report from Adrian Schmidt, who shared on LinkedIn that Google’s crawler had suddenly stopped accessing multiple domains he managed. Despite this, Schmidt noted that live tests via Google Search Console were still functioning without any error messages. Additionally, investigations into the issue revealed no increase in 5xx server errors, nor were there any issues with robots.txt files.

What Could Be Causing the Issue?

Addressing the situation, Mueller suggested that the problem could be tied to shared infrastructure. He explained that when crawling stops across several domains at once, it’s likely related to a common element, such as a shared hosting environment or content delivery network (CDN).

Mueller advised:

“If it's shared across a bunch of domains and focuses on something like crawling, it’s probably an issue with a shared piece of infrastructure. If it’s already recovering, at least it’s not urgent anymore and you have a bit of time to poke at recent changes/infrastructure logs.”

Investigating Infrastructure and CDN

Upon further investigation, it was revealed that all the affected sites were using Cloudflare as their CDN, raising the possibility of an infrastructure-related issue. Cloudflare is widely used to improve website performance and security by distributing content globally through its network of servers. While such services are generally reliable, any hiccups in their systems can impact multiple sites that rely on them.

Mueller suggested that those facing similar issues should examine the data in Google Search Console, which provides insights into crawl statistics. This can help determine whether DNS problems or request failures are responsible for the issue.

He further explained:

"The crawl stats in Search Console will also show a bit more, perhaps help decide between say DNS vs requests failing."

The timing of the disruption can also be an important clue. If crawling issues happen simultaneously across several sites, it’s likely not due to robots.txt or DNS problems, which typically cause more isolated issues.

Impact on Search Rankings

A common concern when Googlebot stops crawling websites is the potential impact on search rankings. Mueller reassured site owners that a temporary disruption, especially one lasting only a few hours, would not typically affect a site’s search visibility.

“If this is from today, and it just lasted a few hours, I wouldn’t expect any visible issues in search.”

However, Mueller’s guidance highlights a critical point: while short-term crawling interruptions may not immediately harm rankings, they can delay Google’s ability to discover and index new content, which is particularly concerning for sites with frequent updates or time-sensitive content.

How-to Prevent and Diagnose Similar Issues

For webmasters managing multiple domains, especially those using shared infrastructure or CDNs like Cloudflare, Mueller's insights offer valuable preventive measures. Here are steps you can take if you notice Googlebot has stopped crawling your sites:

• Check for multi-domain impacts: If the problem occurs across several sites at once, it's likely linked to shared infrastructure.
• Examine your infrastructure: Start by investigating recent changes or logs related to your hosting environment, CDN, or server configurations.
• Leverage Search Console: Use the crawl stats in Search Console to look for patterns in failed requests or DNS issues.
• Review logs: Make sure your logging is comprehensive, as it can provide important clues about the cause of crawling interruptions.
• Monitor your CDN: Keep an eye on any incidents reported by your CDN provider and ensure they have a robust support system in place for emergencies.

Lessons for Site Owners

This incident serves as a reminder of the potential vulnerabilities faced by websites relying on shared infrastructure. Webmasters and businesses should ensure that they have proper logging, monitoring, and support systems in place. This proactive approach can help minimize the impact of disruptions and ensure that crawling issues don’t go unnoticed for extended periods.

In conclusion, if Googlebot stops crawling your domains, it’s essential to act quickly by examining shared infrastructure, reviewing logs, and utilizing Google Search Console data to narrow down the cause. Early detection and swift action can help prevent long-term search visibility issues and ensure Google can continue indexing new content effectively.