Substract only 15% from TM heap for yarn, capped at 500MB

stratosphere-addons/yarn/src/main/java/eu/stratosphere/yarn/ApplicationMaster.java

@@ -62,6 +62,7 @@ import eu.stratosphere.nephele.jobmanager.JobManager;
 public class ApplicationMaster {
 
 	private static final Log LOG = LogFactory.getLog(ApplicationMaster.class);
+	private static final int HEAP_LIMIT_CAP = 500;
 	
 	private void run() throws Exception  {
 		//Utils.logFilesInCurrentDirectory(LOG);
@@ -82,7 +83,10 @@ public class ApplicationMaster {
 		final int memoryPerTaskManager = Integer.valueOf(envs.get(Client.ENV_TM_MEMORY));
 		final int coresPerTaskManager = Integer.valueOf(envs.get(Client.ENV_TM_CORES));
 		
-		final int heapLimit = (int)((float)memoryPerTaskManager*0.7);
+		int heapLimit = (int)((float)memoryPerTaskManager*0.85);
+		if( (memoryPerTaskManager - heapLimit) > HEAP_LIMIT_CAP) {
+			heapLimit = memoryPerTaskManager-HEAP_LIMIT_CAP;
+		}
 		
 		if(currDir == null) {
 			throw new RuntimeException("Current directory unknown");