I am using the embed iframe utility, but I've noticed that it is failing and I don't know if it's related to my search head cluster. We use a VIP for 3 search head clusters. When we embed the html in a report, we've noticed that it's hit or miss if you can view the results. Upon further troubleshooting we've noticed that if we roll through each server using the html embed link (removing the VIP name and putting in the direct IP or Servername) we can eventually see the results on ONE search head. Is that because the embedded iframe is only viewable on the search head where the results were created?
i.e. splunk.companyname.com doesn't always work but if we begin to roll through our VIP names server1:8000 or server2:8000 or server3:8000 we will eventually hit results
I had the same issue and Splunk responded that SPL-96384 is open for the same -
http://answers.splunk.com/answers/242577/splunk-embedded-dashboard-failing-with-search-head.html
For now I suggest you create these dashboards(embedded ones) on a standalone server(which is not part of the cluster) and then use embed url generated from these servers.
Should get fixed in the latest version of Splunk.