The INFO that you are getting, again and again, is probably because multiple users are trying to run on the same cluster that you are running on, at the same time.
In order to resolve this problem, you need to change the setting of the scheduler.
Go to the file /etc/hadoop/conf/capacity-scheduler.xml and change the property yarn.scheduler.capacity.maximum-am-resource-percent from 0.1 to 0.5.
This is a very important parameter to set if you are running a cluster on a single machine where you have got less resource.
Changing this setting increases the fraction of the resources that are made available to be allocated to application masters, this leads in increasing the number of masters possible to run at once and hence increasing the number of possible concurrent applications.