java - Elasticsearch giving failed to connect to discovered node -

my java application log filled below error.any idea why exception.es version:2.4.2

debug transport:319 - [rl'nnd] failed connect discovered node [{node-bla.bla.bla}{ajqo6fq8s_u5f43exnmzpa}{bla.bla.bla:9300}{data=false, master=false}] connecttransportexception[[node-bla.bla.bla][bla.bla.bla:9300] connect_timeout[30s]]; nested: connecttimeoutexception[connection timed out: /bla.bla.bla:9300]; @ org.elasticsearch.transport.netty.nettytransport.connecttochannels(nettytransport.java:987) @ org.elasticsearch.transport.netty.nettytransport.connecttonode(nettytransport.java:920) @ org.elasticsearch.transport.netty.nettytransport.connecttonode(nettytransport.java:893) @ org.elasticsearch.transport.transportservice.connecttonode(transportservice.java:260) @ org.elasticsearch.client.transport.transportclientnodesservice$nodesampler.validatenewnodes(transportclientnodesservice.java:316) @ org.elasticsearch.client.transport.transportclientnodesservice$simplenodesampler.dosample(transportclientnodesservice.java:388) @ org.elasticsearch.client.transport.transportclientnodesservice$nodesampler.sample(transportclientnodesservice.java:300) @ org.elasticsearch.client.transport.transportclientnodesservice$schedulednodesampler.run(transportclientnodesservice.java:333) @ java.util.concurrent.threadpoolexecutor.runworker(threadpoolexecutor.java:1142) @ java.util.concurrent.threadpoolexecutor$worker.run(threadpoolexecutor.java:617) @ java.lang.thread.run(thread.java:745)

after 45 minutes above exception stopped , below exception started coming.is there connection retry time out in es?

netty:1095 - [plug] disconnecting [{node-bla.bla.bla}{68xnc79rtdklc55g-bmcfq}{10.0.2.77}{bla.bla.bla:9300}{data=false, master=false}], channel closed event