SharePoint 2013 Search Stopped Working

All of sudden one day our search started to throw error for "Something went wrong", the ULS logs were showing below error:

The processing of item fails with error Cannot plan query for index system SP6bd7dedd292c. Index fragment '0' has no available cells.

Basically it appears the search index partition becomes corrupted.

Following steps resolved the issue:

1. Stop the Timer Service
2. Clear the configuration cache - Find in %SystemDrive%\ProgramData\Microsoft\SharePoint\Config\ the folder where the file cache.ini exists
3. Delete every file from this folder EXCEPT cache.ini
4. Open cache.ini, delete the content and put '1' (without the quotes) in it and save the file.
5. Restart the Timer Service.
6. Reset the Index
7. Perform Full crawl

Hope this helps!!!

Ref: https://sharepoint.stackexchange.com/questions/114273/sharepoint-2013-search-not-working-ootb