EAM stuck in STARTING status in host preparation tab

Products

• VMware NSX

Issue/Introduction

• vSphere Web Client-> Network & Security -> Installation -> Host preparation, the EAM status always shows STARTING. 
• From NSX Manager log, you will see the following error messages printed constantly.
  
  2018-12-02 04:55:00.040 CST  WARN TaskFrameworkExecutor-6 VSMAgentStateUpdater:272 - It seems previous run of child job jobdata-236480 of this this job jobdata-178372 is still going on even after next run has started. looks like there is some issue. exiting this run now
2018-12-02 05:00:00.070 CST  WARN TaskFrameworkExecutor-15 VSMAgentStateUpdater:272 - It seems previous run of child job jobdata-236480 of this this job jobdata-178372 is still going on even after next run has started. looks like there is some issue. exiting this run now
2018-12-02 05:05:00.039 CST  WARN TaskFrameworkExecutor-19 VSMAgentStateUpdater:272 - It seems previous run of child job jobdata-236480 of this this job jobdata-178372 is still going on even after next run has started. looks like there is some issue. exiting this run now
  
  

Environment

VMware NSX Data Center for vSphere 6.4.x
VMware NSX Data Center for vSphere 6.3.x

Cause

NSX Manager scheduled reindex task that runs at 12:00 AM on 1st Saturday of every month.
If DB operations are performed on the same table where reindexing is happening, the job will fail.

Resolution

This issue is resolved in VMware NSX Data Center for vSphere 6.4.5

Workaround:
NSX manager reboot would clear previous jobdata and resume EAM status to UP.