ambari + API syntax in order to change the parameters of the ambari services

Here are the steps to update service configurations using REST API.

• Find your cluster name using the below the url, if you don't know the cluster name, it requires in the below step - http://<AMBARI-SERVER>:8080/api/v1/clusters/
• Find the property name, type from the cluster configurations json which can be accessed using the url, replace by cluster name from above step - http://<AMBARI-SERVER>:8080/api/v1/clusters/<CLUSTER_NAME>
• Let's say I wanted to update YARN node manager property yarn.nodemanager.resource.memory-mb, Create a json file as below -

newconfigs.json

{  "Clusters": {    "desired_config": {      "type": "yarn-site",      "tag": "version1502226523283",      "properties": {        "yarn.nodemanager.resource.memory-mb": "200000"      }    }  }}

tag number should be unique - just give some random number, You can update this configuration in Ambari usng the below command. Below API uses REST - PUT method.

curl -H "X-Requested-By: ambari" -X PUT -u admin:admin -d @newconfigs.json http://<AMBARI-SERVER>:8080/api/v1/clusters/<CLUSTER_NAME>

Refer below ambari official REST api documentations for more details.

https://github.com/apache/ambari/blob/trunk/ambari-server/docs/api/v1/configuration.md