None of the configured nodes are available - 127.0.0.1

[RAM_NATHAN]

I'm getting mentioned error in 5.6.3.

NoNodeAvailableException[None of the configured nodes are available: [{#transport#-1}{Lx1sIaSdTpCXG_fZQY5p1A}{127.0.0.1}{127.0.0.1:9300}]]

curl "localhost:9200"
{
"name" : "",
"cluster_name" : "elasticsearch",
"cluster_uuid" : "",
"version" : {
"number" : "5.6.3",
"build_hash" : "",
"build_date" : "2017-10-06T20:33:39.012Z",
"build_snapshot" : false,
"lucene_version" : "6.6.1"
},
"tagline" : "You Know, for Search"
}

I searched all topics realted to this error , nothing helped really

esClient = new PreBuiltTransportClient(Settings.EMPTY)
.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("127.0.0.1"),9300));

I'm using settings.EMPTY as my cluster name is commented in elasticsearch.yml

network.host: 127.0.0.1
transport.tcp.port: 9300

[dadoonet (David Pilato)]

Check that you don't have any firewall on port 9300.

Also prefer using the rest client instead.

[RAM_NATHAN]

I'm getting below error in elasticsearch log

Caused by: java.io.StreamCorruptedException: invalid internal transport message format, got (ff,f4,ff,fd)
at org.elasticsearch.transport.TcpTransport.validateMessageHeader(TcpTransport.java:1276) ~[elasticsearch-5.6.3.jar:5.6.3]
at org.elasticsearch.transport.netty4.Netty4SizeHeaderFrameDecoder.decode(Netty4SizeHeaderFrameDecoder.java:36) ~[?:?]
at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:489) ~[?:?]
at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:428) ~[?:?]

what should i check? Its upgraded from ES 1.* to 5.6.3

[dadoonet (David Pilato)]

May be you are not using the same version on both sides (client and server). Or you are using https or something...

[RAM_NATHAN]

Issue was because of conflicting jar io.netty. I got below error
"NoClassDefFoundError[Could not initialize class io.netty.channel.ChannelOutboundBuffer];"'

Resolved now