private boolean masterExists ( ) { String webPort = mAlluxioConf . get ( PropertyKey . MASTER_WEB_PORT ) ; try { URL myURL = new URL ( "http://" + mMasterAddress + ":" + webPort + Constants . REST_API_PREFIX + "/master/version" ) ; LOG . debug ( "Checking for master at: " + myURL . toString ( ) ) ; HttpURLConnection connection = ( HttpURLConnection ) myURL . openConnection ( ) ; connection . setRequestMethod ( HttpMethod . GET ) ; int resCode = connection . getResponseCode ( ) ; LOG . debug ( "Response code from master was: " + Integer . toString ( resCode ) ) ; connection . disconnect ( ) ; return resCode == HttpURLConnection . HTTP_OK ; } catch ( MalformedURLException e ) { LOG . error ( "Malformed URL in attempt to check if master is running already" , e ) ; } catch ( IOException e ) { LOG . debug ( "No existing master found" , e ) ; } return false ; }
Checks if an Alluxio master node is already running or not on the master address given .