What timeout value determines elasticsearch.transport.NodeDisconnectedException


We have development and prod clusters in Azure. A week and a half ago, for the first time, as far as I know, we saw lots of errors like this (for multiple nodes)

[2016-04-01 18:35:26,436][DEBUG][action.admin.indices.stats] [VMNAME] [twittervolumeitems_2016.03.08][2], node[U04KSaiNT_KYWEQUyo8ZHA], [R], s[STARTED]: failed to execute [org.elasticsearch.action.admin.indices.stats.IndicesStatsRequest@11fd8625]
org.elasticsearch.transport.NodeDisconnectedException: [VMNAME][inet[IPRanges]][indices:monitor/stats[s]] disconnected

(For reference, it looks to be similar to what was reported here: http://elasticsearch-users.115913.n3.nabble.com/Seeing-Frequent-NodeNotConnectedException-errors-td4068719.html)

Question is: What timeout value determines when the cluster becomes yellow as a result of these errors? Is it the "discovery.zen.ping.timeout:" setting or something else?

Thanks in advance!