vCenter server heartbeat log

Hi,

I am checking the logs under:

• C:\Program Files\VMware\VMware vCenter Server Heartbeat\tomcat\hblog

I am seeing the following errors:

...

[2013-08-07 23:46:20,000] WARN444813[PeriodicTaskScheduler](com.neverfail.webservices.addins.AddInManager) - VCENTERADDIN>  Failed Service Instance login

java.rmi.RemoteException: VI SDK invoke exception:java.net.ConnectException: Connection refused: connect

  at com.vmware.vim25.ws.WSClient.invoke(WSClient.java:181)

  at com.vmware.vim25.ws.WSClient.invoke(WSClient.java:123)

  at com.vmware.vim25.ws.VimStub.retrieveServiceContent(VimStub.java:1449)

  at com.vmware.vim25.mo.ServiceInstance.<init>(ServiceInstance.java:85)

  at com.vmware.vim25.mo.ServiceInstance.<init>(ServiceInstance.java:69)

  at com.neverfail.webservices.vcenter.VCenterAddIn.validateLogin(VCenterAddIn.java:644)

  at com.neverfail.webservices.vcenter.VCenterAddIn.getServiceInstance(VCenterAddIn.java:688)

  at com.neverfail.webservices.vcenter.VCenterAddIn.connectVCenter(VCenterAddIn.java:304)

  at com.neverfail.webservices.vcenter.VCenterAddIn.run(VCenterAddIn.java:293)

  at com.neverfail.webservices.servlet.Scheduler.run(Scheduler.java:39)

  at java.util.TimerThread.mainLoop(Timer.java:512)

  at java.util.TimerThread.run(Timer.java:462)

Does anyone know what that means?