--- layout: default title: cat master parent: CAT grand_parent: REST API reference nav_order: 30 has_children: false --- # cat master The cat master operation lists information that helps identify the elected master node. ## Example ``` GET _cat/master?v ``` ## Path and HTTP methods ``` GET _cat/master ``` ## URL parameters All cat master URL parameters are optional. In addition to the [common URL parameters]({{site.url}}{{site.baseurl}}/opensearch/rest-api/cat/index#common-url-parameters), you can specify the following parameters: Parameter | Type | Description :--- | :--- | :--- master_timeout | Time | The amount of time to wait for a connection to the master node. Default is 30 seconds. ## Response ```json id | host | ip | node ZaIkkUd4TEiAihqJGkp5CA | 172.18.0.3 | 172.18.0.3 | odfe-node2 ```