OpsCenter not getting data after restart of server - datastax

Question

we are using Datastax Enterprize edition. We are running a 2 node cluster. We get the message: After restarting of OpsCentre node getting below error.
2017-03-20 14:49:45,819 [opscenterd] ERROR: Unhandled error in
Deferred: There are no clusters with name or ID 'tracking'
File "/usr/share/opscenter/lib/py/twisted/internet/defer.py", line 1124, in _inlineCallbacks
result = g.send(result)
File "/usr/share/opscenter/jython/Lib/site-packages/opscenterd/WebServer.py",
line 523, in ClusterController
File "/usr/share/opscenter/jython/Lib/site-packages/opscenterd/ClusterServices.py",
line 181, in __getitem__
(MainThread)
Agents Log
WARN [async-dispatch-23] 2017-03-20 17:13:45,230 Attempted to ping opscenterd on stomp but did not receive a reply in time, will retry again later.
ERROR [StompConnection receiver] 2017-03-20 17:13:45,230 Mar 20, 2017 5:13:45 PM org.jgroups.client.StompConnection run
SEVERE: JGRP000112: Connection closed unexpectedly:
java.net.SocketException: Socket closed
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.socketRead(SocketInputStream.java:116)
at java.net.SocketInputStream.read(SocketInputStream.java:170)
at java.net.SocketInputStream.read(SocketInputStream.java:141)
at java.net.SocketInputStream.read(SocketInputStream.java:223)
at java.io.FilterInputStream.read(FilterInputStream.java:83)
at org.jgroups.util.Util.readLine(Util.java:2825)
at org.jgroups.protocols.STOMP.readFrame(STOMP.java:240)
at org.jgroups.client.StompConnection.run(StompConnection.java:274)
at java.lang.Thread.run(Thread.java:745)
INFO [async-dispatch-23] 2017-03-20 17:13:45,236 Starting DynamicEnvironmentComponent
INFO [async-dispatch-23] 2017-03-20 17:13:45,512 Dynamic environment script output: paths:
cassandra-conf: /etc/dse//cassandra
cassandra-log: /var/log/cassandra
hadoop-log: /var/log/hadoop/userlogs
spark-log: /var/log/spark
dse-env: /etc/dse
dse-conf: /etc/dse/
hadoop-conf: /etc/dse/hadoop2-client
spark-conf: /etc/dse//spark
INFO [async-dispatch-23] 2017-03-20 17:13:45,522 Starting storage database connection.
ERROR [async-dispatch-23] 2017-03-20 17:13:47,737 Can't connect to Cassandra (All host(s) tried for query failed (tried: /127.0.0.1:9042 (com.datastax.driver.core.exceptions.TransportException: [/127.0.0.1:9042] Cannot connect))), retrying soon.
INFO [async-dispatch-23] 2017-03-20 17:13:47,738 Starting monitored database connection.
ERROR [async-dispatch-23] 2017-03-20 17:13:49,965 Can't connect to Cassandra, authentication error, please carefully check your Auth settings, retrying soon.
INFO [async-dispatch-23] 2017-03-20 17:13:49,967 Starting RepairComponent
INFO [async-dispatch-23] 2017-03-20 17:13:49,970 Finished starting system.
INFO [async-dispatch-26] 2017-03-20 17:13:59,971 Starting system.
INFO [async-dispatch-26] 2017-03-20 17:13:59,973 Configuration change for component class opsagent.nodedetails.repair.RepairComponent: before: {:send-repair-fn #object[opsagent.nodedetails.repair.jmx$send_repair 0x76028b5c "opsagent.nodedetails.repair.jmx$send_repair#76028b5c"], :parse-notification-fn #object[opsagent.nodedetails.repair.jmx$parse_notification 0x5e84cf80 "opsagent.nodedetails.repair.jmx$parse_notification#5e84cf80"]}, after: {:send-repair-fn nil, :parse-notification-fn nil}
INFO [async-dispatch-26] 2017-03-20 17:13:59,974 The following components have had a config change and will be rebuilt and restarted: (:repair-component)
INFO [async-dispatch-26] 2017-03-20 17:13:59,975 The component restart for (:repair-component) when accounting for dependencies requires these components to be restarted #{:repair-component :http-server}
INFO [async-dispatch-26] 2017-03-20 17:13:59,976 Stopping RepairComponent.
INFO [async-dispatch-26] 2017-03-20 17:13:59,977 Starting StompComponent
INFO [async-dispatch-26] 2017-03-20 17:13:59,978 SSL communication is disabled
INFO [async-dispatch-26] 2017-03-20 17:13:59,978 Creating stomp connection to 192.168.136.250:61620
ERROR [async-dispatch-26] 2017-03-20 17:13:59,980 Mar 20, 2017 5:13:59 PM org.jgroups.client.StompConnection connect
INFO: Connected to 192.168.136.250:61620
I am not able to understand whats wrong with Agent and OpsCentre?