Kibana would report Courier Fetch: Bad Gateway.
here are my logs
[2016-06-15 11:32:38,512][DEBUG][action.admin.cluster.node.stats] [elastic-kibana] failed to execute on node [Cr1WzqKXTAmtVy15adTRbg]
ReceiveTimeoutTransportException[[elasticsearch-1][192.168.1.102:9300][cluster:monitor/nodes/stats[n]] request_id [189677] timed out after [15099ms]]
at org.elasticsearch.transport.TransportService$TimeoutHandler.run(TransportService.java:679)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
[2016-06-15 11:32:38,899][DEBUG][action.admin.cluster.node.stats] [elastic-kibana] failed to execute on node [CIqJQI_SQlK0HbP4naWhkA]
ReceiveTimeoutTransportException[[elasticsearch-2][192.168.1.103:9300][cluster:monitor/nodes/stats[n]] request_id [189678] timed out after [15499ms]]
at org.elasticsearch.transport.TransportService$TimeoutHandler.run(TransportService.java:679)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
[2016-06-15 11:32:59,304][WARN ][transport ] [elastic-kibana] Received response for a request that has timed out, sent [35904ms] ago, timed out [20805ms] ago, action [cluster:monitor/nodes/stats[n]], node [{elasticsearch-1}{Cr1WzqKXTAmtVy15adTRbg}{192.168.1.102}{192.168.1.102:9300}{master=false}], id [189677]
[2016-06-15 11:33:10,304][WARN ][transport ] [elastic-kibana] Received response for a request that has timed out, sent [46904ms] ago, timed out [31405ms] ago, action [cluster:monitor/nodes/stats[n]], node [{elasticsearch-2}{CIqJQI_SQlK0HbP4naWhkA}{192.168.1.103}{192.168.1.103:9300}{master=false}], id [189678]