Search Service Application : Full Crawl Takes Forever to Complete.

Issue:

Search Service Application crawls never completed.


Solution:

1. Check if there is any warning/error in your SSA Topology.
2. If any, stop the crawling. Then, reset index. Once reset, check again the topology if the warning/error gone.
1. If gone, do full crawl again.
2. If persist, clear SharePoint Cache. You may refer to my earlier post here. Once cleared, reset index again, and the recrawl.
3. If all steps done but it still takes long time to crawl; perhaps the SSA Index Component is not enough to cater your item. If you estimated number of documents in your SP2013 roughly more than 10k, the default SSA might not enough. You need to add more Index Component.

My web application has more than 1,000,000 documents to be crawled. Using default SSA setting (1 index component) cause my SSA to stuck in crawling for more than 17 days and never progressing. Increasing the Index Component to 4, and move the indexing folder to another Drive, makes my crawling complete within 6 days. (Well even still consider sucks, it is still better than 17 days, isn't it? :P)

You may refer to this post on how to recreate the SSA Topology