Restarting a virtual machine does not give me a guarantee as always because I’ve encountered many cases in which something went wrong after restarting. One of the Search in my customers’ SharePoint 2013 farm recently got several errors on its component after a SharePoint virtual machine running a set of Search components was restarted. At least Content Processing, Analytics Processing, Query Processing and Index Partition have a red triangle icon which you wish not to see in your life. The SharePoint Search Host Controller (Windows service) somehow continuously terminated after restarting. I was called to look into this issue because I was the one who designed this Search into multi-server Search farm.
Firstly, I tried to verify the account that ran SharePoint Search Host Controller to ensure it wasn’t being locked and password was valid. I got the administrator to verify again carefully, and tried to start SharePoint Search Host Controller but there was not a luck in that period of time.
I suggest the SharePoint administrator to use the Local System account for SharePoint Search Host Controller service. The service then was able to be in the Running mode but the Search Host Controller service instance in SharePoint could not be started. Due to the urgent time because Search was used as a search-driven application for my customer then I would plan to recover Search service application. Sometimes you have an idea to solve a problem but you ponder over your plan because you don’t have much time. That happens so often to me during my time supporting many government agencies.
For the last check, perhaps that’s my luck I realized that the configuration file (located at C:\Program Files\Microsoft Office Servers\15.0\Data\Office Server\Applications\Search\Nodes<Node_Number>\AdminComponent1\Configuration\Local) of each Search component on each Search server role was not consistent. I copied the Node.ini file from the working component to the corrupted one. After that I managed to successfully start SharePoint Search Host Controller service and restarted SharePoint Search related services. The red triangle icon disappeared but my index partition was degraded. This kind of issue is common and I was able to sort it out after reading some good article over the Internet.
What I would say is that the Node.ini file that contains endpoint configuration of Search components. In my case the corrupted ones were Index component and Administration component. The corruption caused the inconsistent synchronized configuration among Search components, making SharePoint Search Host Controller service unable to start. So how do you really maintain such a configuration file? There would not be one answer. There may be perhaps you would back up the entirely Search inside this folder C:\Program Files\Microsoft Office Servers\15.0\Data\Office Server\Applications\Search\ for further recovery if something badly happens.
And again don’t expect restarting virtual machine always gives you safety in your system. Sometimes it does, and sometimes it gives a nightmare.