I have a SharePoint 2013 farm and on my applications server the content processing component is degraded and my search crawl will not complete.
Any ideas how I can fix this?
I would start by making sure the file system that contains your index is sound. You also have an end point failure which may be that the CPC is not provisioned correctly. Start with a reboot and evaluate the components. Turn logging up to verbose for Search and you will get a TON of information on that is going on dumped to the ULS logs.
I suspect it's a drive failure though.