Get value from agent failed: ZBX_TCP_READ() failed: [4] Interrupted system call

Get value from agent failed: ZBX_TCP_READ() failed: [4] Interrupted system call

I got this error from a MongoDB VM I had just fired up. As I was investigating, I found that there was a hung connection to the primary resolver listed in /etc/resolv.conf. Turns out that network segment didn't have a firewall exclusion for the new caching name server I had installed not too long ago. I  added a firewall exclusion and a minute or so later the node was reporting data in my Zabbix web console. UPDATE: I've also experienced the same issue where the node had no issue contacting the resolver listed in /etc/resolv.conf. The fix was to add an entry in /etc/hosts for the Zabbix server. It's odd that it only affected one RHEL node.

TLDR: This error message is related to some type of failure of the DNS subsystem on the target node.