kibana报错Request Timeout after 30000ms

{"type":"error","@timestamp":"2018-03-31T00:45:40Z",
"tags":["warning","monitoring-ui","kibana-monitoring"],
"pid":21192,"level":"error",
"error":{"message":"Request Timeout after 30000ms","name":"Error",
"stack":"Error: Request Timeout after 30000ms\n    
at /usr/local/bin/kibana-6.1.2-linux-x86_64/node_modules/elasticsearch/src/lib/transport.js:342:15\n    
at Timeout.<anonymous> (/usr/local/bin/kibana-6.1.2-linux-x86_64/node_modules/elasticsearch/src/lib/transport.js:371:7)\n    
at ontimeout (timers.js:386:11)\n    at tryOnTimeout (timers.js:250:5)\n    
at Timer.listOnTimeout (timers.js:214:5)"},"message":"Request Timeout after 30000ms"}
再次启动没有问题，隔了一段时间就又停了