Possible crashes of the resolver

We have issued and pushed a patch to all of the affected resolvers. No further action is needed from your end. We will incorporate the patch into a hotfix version that we will release tomorrow. Thank you for your understanding and patience.

After extensive investigation, we verified that less than 5 % of customers were affected by the crashes, we’re therefore lowering the severity to “Minor”. While the true root cause that leads to the crashes is still undetermined and is likely a combination of several factors, we have identified a related issue with automatic resolver recovery for which we’re already developing a fix and we aim to roll it out as soon as possible.

We’re still investigating the root cause of the issue. So far, we have identified that with a high probability certain domain caches became corrupted approximately between 3:00 AM and 5:00 AM UTC. DNS resolvers that attempted to load these caches were unable to properly access the required information which resulted in a higher than expected DNS resolution error rate.

This morning, we detected a technical issue causing outages in some customer DNS resolvers. The likely cause is a corrupted threat database cache. Our engineers are working diligently to identify and fix the root cause.

Impact:

• Some customers may experience issues with DNS resolvers.
• Threat blocking may not be functioning temporarily.

Recommended Action for Customers:

• For a quick fix, please follow the instructions sent in the email communication or contact our technical support team.

Next Steps:

• We will keep you updated on the progress of the situation.
• We apologize for any inconvenience and thank you for your understanding.

We observe a single cases of crashes of On-Prem resolvers which may result in stopping the resolving service. We are doing our best to resolve the issue as soon as possible.

The immediate workaround is to reboot the DNS server.