OverviewIn certain cases, when users browse to a website, the web page keeps on spinning and eventually times out. Or certain content on the web page wont load. When edge cache is turned off, the web page loads instantly. This issue has been seen in versions 7.0.2 and above (uptill 7.4)
CauseEdge-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.
ResolutionThe resolution is to terminate DNS on squid.
We cannot terminate DNS on the Exinda, since it is required for multiple purposes.
Firmware version 7.4.1 has a fix for this where squid's DNS has been taken out of the picture. It does not interfere with the caching process, hence doesn't cause web time outs
Additional InformationHow to identify the symptoms:
a) Do an nslookup on the website having the problem with edge cache on. nslookup should be done from the Exinda.
If the lookup is not instant, then it points to this issue and the fix is in 7.4.1