node.js - elastic search no living connection when sniffing on startup -

i use elastic search api node.js.

my code :

var elasticclient=new elasticsearch.client( { sniffonstart:true, sniffonconnectionfault:true, sniffinterval:540000, hosts:['\* elastic servers*\'] } ); 

whenever delete sniffonstart works. when sniffonstart remains throws following error after trying bulk:

elasticsearch warnning: date no living connection  {error:no living connections  @ ... (script paths..) message:'no living connections', body:undefined, status:undefined }