[Exception] example/bin/getstarted-debug-gnu

[mingyitianxia]

when I run example/bin/getstarted-debug-gnu, the follow bugs apper:
[root@5b9dbaaa148a cpp-elasticsearch-master]# example/bin/getstarted-debug-gnu
Official name is: localhost, IP addresses: 127.0.0.1 127.0.0.1 , session keep alive connection.
Couldn't connect, connection refused.
Exception caught while reading socket - Connection refused.
Exception in src/http/http.cpp l. 180 ->
error set by getsockopt.
get(0) failed in ElasticSearch::isActive(). Exception caught: error set by getsockopt.
Exception in src/elasticsearch/elasticsearch.cpp l. 14 ->
Cannot create engine, database is not active.
terminate called after throwing an instance of 'Exception'
Aborted (core dumped)

If you know the reason, please help me!
TKS!