configure not getting called when changing configuration

<div style=”color: #000000; font-family: Calibri, sans-serif; font-size: 14px; line-height: normal;”>I have a master.py with install(self, env), configure(self, env), start(self, env) & stop(self, env). [Its declared MASTER in metainfo.xml ..]. I am running Ambari 2.1.0</div>

1. When the admin changes the configuration from the UI, the master.py’s configure() is not called. Any reason why ? How do I change the core-site.xml for example when the configuration gets changed from ambari-server UI ?
2. When installing the product the configure() is never called. I have to explicitly call self.configure(env) at the end of install(). Is that normal too ?

<div style=”color: #000000; font-family: Calibri, sans-serif; font-size: 14px; line-height: normal;”>Thanks</div>
<div style=”color: #000000; font-family: Calibri, sans-serif; font-size: 14px; line-height: normal;”>-Sathya</div>