Overview
In certain cases, when users browse a website, the web page keeps on loading and eventually times out or certain content on the web page will not load. When Edge Cache is turned off, the web page loads instantly. This article provides a resolution for this error.
Environment
Exinda v7.0.2 and above (up to v7.4.1)
Root Cause
Edge cache requires a working DNS server to function properly. Exinda uses Squid for caching and Squid has its own DNS as well. When the DNS on the Exinda and the DNS on the Squid clash, it causes a time out on the web pages.
Resolution
To confirm this error, do a nslookup on the website having the problem with Edge Cache on. The nslookup should be done from the Exinda. If the lookup is not instant, then it points to this issue.
The resolution for this error in version 7.0.2 and above (up to 7.4.1) is to terminate DNS on Squid. It is not possible to terminate DNS on the Exinda since it is required for multiple purposes.
Another option is to upgrade to version 7.4.1, which has a fix for this where DNS of Squid has been taken out of the picture. It does not interfere with the caching process, hence does not cause web time outs.