Understand the default configuration
Elasticsearch configuration file
The main configuration file for Elasticsearch is installdir/elasticsearch/config/elasticsearch.yml.
By default, Elasticsearch will use port 9200 for requests and port 9300 for communication between nodes within the cluster. If these ports are in use when the server starts, it will attempt to use the next available port, such as 9201 or 9301.
You can set custom ports using the configuration file, together with details such as the cluster name (elasticsearch by default), node name, address binding and discovery settings. All these settings are needed to add more nodes to your Elasticsearch cluster.
Elasticsearch doesn’t include built-in user/password authentication. This can be added using external plugins.
Elasticsearch log file
The Elasticsearch log file is created at installdir/elasticsearch/logs/elasticsearch.log.