Error log on Ambari for Yarn. Connection failed to http://ip-172-31-18-234.ec2.internal:8042/ws/v1/node/info (Traceback (most recent call last): File "/var/lib/ambari-agent/cache/common-services/YARN/2.1.0.2.0/package/alerts/alert_nodemanager_health.py", line 171, in execute url_response = urllib2.urlopen(query, timeout=connection_timeout) File "/usr/lib64/python2.7/urllib2.py", line 154, in urlopen return opener.open(url, data, timeout) File "/usr/lib64/python2.7/urllib2.py", line 431, in open response = self._open(req, data) File "/usr/lib64/python2.7/urllib2.py", line 449, in _open '_open', req) File "/usr/lib64/python2.7/urllib2.py", line 409, in _call_chain result = func(*args) File "/usr/lib64/python2.7/urllib2.py", line 1244, in http_open return self.do_open(httplib.HTTPConnection, req) File "/usr/lib64/python2.7/urllib2.py", line 1214, in do_open raise URLError(err) URLError: <urlopen error [Errno 111] Connection refused> Connection failed to http://ip-172-31-18-234.ec2.internal:8042 (<urlopen error [Errno 111] Connection refused >) Sudo top on Slave 882 yarn 20 0 397272 31392 456 S 1557 0.0 566:11.83 java 1 root 20 0 194556 7676 4160 S 0.0 0.0 1:31.20 systemd 2 root 20 0 0 0 0 S 0.0 0.0 0:00.21 kthreadd 3 root 20 0 0 0 0 S 0.0 0.0 0:07.80 ksoftirqd/0 5 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 kworker/0:0H 7 root rt 0 0 0 0 S 0.0 0.0 0:00.50 migration/0 8 root 20 0 0 0 0 S 0.0 0.0 0:00.00 rcu_bh 9 root 20 0 0 0 0 S 0.0 0.0 0:52.80 rcu_sched 10 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 lru-add-drain 11 root rt 0 0 0 0 S 0.0 0.0 0:00.98 watchdog/0 12 root rt 0 0 0 0 S 0.0 0.0 0:00.82 watchdog/1 13 root rt 0 0 0 0 S 0.0 0.0 0:00.53 migration/1 14 root 20 0 0 0 0 S 0.0 0.0 0:08.16 ksoftirqd/1 16 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 kworker/1:0H 17 root rt 0 0 0 0 S 0.0 0.0 0:00.82 watchdog/2 18 root rt 0 0 0 0 S 0.0 0.0 0:00.50 migration/2 <br> ... View more