2018-12-11 10:17:44,294  ERROR [solr.tracker.AbstractTracker] [org.alfresco.solr.AlfrescoCoreAdminHandler@4d88d537_Worker-1] Model tracking failed
 java.net.ConnectException: Connection refused: connect
	at java.net.DualStackPlainSocketImpl.connect0(Native Method)
	at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:79)
	at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
	at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
	at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
	at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
	at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
	at java.net.Socket.connect(Socket.java:589)
	at sun.security.ssl.SSLSocketImpl.connect(SSLSocketImpl.java:668)
	at sun.security.ssl.SSLSocketImpl.<init>(SSLSocketImpl.java:472)
	at sun.security.ssl.SSLSocketFactoryImpl.createSocket(SSLSocketFactoryImpl.java:153)
	at org.alfresco.encryption.ssl.AuthSSLProtocolSocketFactory.createSocket(AuthSSLProtocolSocketFactory.java:168)
	at org.apache.commons.httpclient.HttpConnection.open(HttpConnection.java:707)
	at org.apache.commons.httpclient.MultiThreadedHttpConnectionManager$HttpConnectionAdapter.open(MultiThreadedHttpConnectionManager.java:1361)
	at org.apache.commons.httpclient.HttpMethodDirector.executeWithRetry(HttpMethodDirector.java:387)
	at org.apache.commons.httpclient.HttpMethodDirector.executeMethod(HttpMethodDirector.java:171)
	at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:397)
	at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:323)
	at org.alfresco.httpclient.AbstractHttpClient.executeMethod(AbstractHttpClient.java:135)
	at org.alfresco.httpclient.AbstractHttpClient.sendRemoteRequest(AbstractHttpClient.java:111)
	at org.alfresco.httpclient.HttpClientFactory$HttpsClient.sendRequest(HttpClientFactory.java:408)
	at org.alfresco.solr.client.SOLRAPIClient.getModelsDiff(SOLRAPIClient.java:1178)
	at org.alfresco.solr.tracker.ModelTracker.trackModelsImpl(ModelTracker.java:256)
	at org.alfresco.solr.tracker.ModelTracker.trackModels(ModelTracker.java:214)
	at org.alfresco.solr.tracker.ModelTracker.ensureFirstModelSync(ModelTracker.java:236)
	at org.alfresco.solr.tracker.CoreWatcherJob.registerForCore(CoreWatcherJob.java:145)
	at org.alfresco.solr.tracker.CoreWatcherJob.execute(CoreWatcherJob.java:82)
	at org.quartz.core.JobRunShell.run(JobRunShell.java:216)
	at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:563)