I opened Kibana and got following message:
Discover: Request Timeout after 30000ms
inside of /var/log/elasticsearch/elasticsearch.log, I'm seeing a lot of messages such as following:
[2017-03-22T15:17:26,283][WARN ][o.e.m.j.JvmGcMonitorService] [k_slO6-] [gc][1119237] overhead, spent [5.4s] collecting in the last [5.4s]
[2017-03-22T15:17:29,945][WARN ][o.e.m.j.JvmGcMonitorService] [k_slO6-] [gc][1119238] overhead, spent [3.5s] collecting in the last [3.6s]
[2017-03-22T15:17:34,689][WARN ][o.e.m.j.JvmGcMonitorService] [k_slO6-] [gc][1119239] overhead, spent [4.6s] collecting in the last [4.7s]
[2017-03-22T15:17:38,594][WARN ][o.e.m.j.JvmGcMonitorService] [k_slO6-] [gc][1119240] overhead, spent [3.8s] collecting in the last [3.9s]
[2017-03-22T15:17:43,868][WARN ][o.e.m.j.JvmGcMonitorService] [k_slO6-] [gc][1119241] overhead, spent [4.5s] collecting in the last [5.2s]
[2017-03-22T15:17:47,749][WARN ][o.e.m.j.JvmGcMonitorService] [k_slO6-] [gc][1119242] overhead, spent [3.1s] collecting in the last [3.8s]
[2017-03-22T15:17:53,112][WARN ][o.e.m.j.JvmGcMonitorService] [k_slO6-] [gc][1119243] overhead, spent [4.9s] collecting in the last [5.3s]
[2017-03-22T15:17:57,095][WARN ][o.e.m.j.JvmGcMonitorService] [k_slO6-] [gc][1119244] overhead, spent [3.5s] collecting in the last [3.9s]
[2017-03-22T15:18:02,464][INFO ][o.e.m.j.JvmGcMonitorService] [k_slO6-] [gc][old][1119245][135793] duration [5s], collections [1]/[5.3s], total [5s]/[3.1h], memory [1.5gb]->[1.6gb]/[1.9gb], all_pools {[young] [50.8mb]->[113.9mb]/[399.4mb]}{[survivor] [0b]->[0b]/[49.8mb]}{[old] [1.4gb]->[1.5gb]/[1.5gb]}
my load average isn't so bad:
# uptime
15:21:31 up 12 days, 23:32, 2 users, load average: 1.48, 1.76, 1.99
#
Please advise.