We have just installed a Dec 2017 CU on our SharePoint 2013 on-prem farm and after everything was installed our users Arent able to search for items.
All the services are working, crawl is working but it looks like it is now running for 23 hours. Previously our incremental crawls were done in 10-15 minutes...
Did we do something wrong or do the CU updates reset the search index?
And now IS worker process and SharePoint search component are fighting for CPU both of them go as high as 80% CPU usage, then the other process takes over and that is making our Servers be stuck in 100% CPU.