(I think) this occurred after upgrading from Ambari 2.4.2 to 2.5.0.3 (only looked for this when on Ambari 2.5.1.0)
Here are the messages in SmartSense View
Found these messages in /var/log/ambari-server/ambari-server.log when clicking on launch SmartSense View
14 Jul 2017 11:14:05,523 ERROR [ambari-client-thread-467377] ServerProxy:162 - Failed to execute GET /recommendations. Reason: Connection refused 14 Jul 2017 11:14:13,695 ERROR [ambari-client-thread-467507] ServerProxy:162 - Failed to execute GET /context. Reason: Connection refused 14 Jul 2017 11:14:14,900 ERROR [ambari-client-thread-467507] ServerProxy:162 - Failed to execute GET /checkconfig. Reason: Connection refused
Diff'ing current hst-server.ini versus a previous (think it was from Ambari 2.4.2) yields
# diff conf/hst-server.ini conf_13_04_17_04_17.save/ 2,4d1 < enable.flex.subscription = false < smartsense.id=X-00000000-X-00000000 < flex.subscription.id = 6a4 > smartsense.id=X-00000000-X-00000000 27,28d24 < url = http://:9000 < max.heap = 2048 30d25 < run.as.user = 33d27 < version = 1.4.0.2.5.0.3-7 52,57d45 < [recommendation] < auto.download.interval = 300 < feedback.push.maxentries = 50 < feedback.push.interval = 1800 < expiry = 30 <
The issue was the missing HST server name in the [server] url property (ie server.url in Ambari if you can find it - this was the issue - and still is - this ghosted into and then out of view in Ambari SmartSense Config tab)
Managed to change the server.url property to http://<hst server name>:9000 in Ambari (when it reappeared)
Restarted SmartSense server
And retried the SmartSense view and it now works fine.
TBC - work out why server.url property is not always visible in the SmartSense Config tabs all the time.
