A company deploys Enterprise Search for SharePoint Server 2013.
Some crawls of result sources fail to complete.
You need to examine detailed information about crawl rate, crawl latency, crawl freshness, content processing,
CPU and memory load, continuous crawls, and the crawl queue to determine how you should alter crawling.
What should you review?

A.
Microsoft Search Server performance counters

B.
The crawl log

C.
Crawl-health reports

D.
Unified Logging Service (ULS) logs

Explanation:
Crawl-health reports provide detailed information about crawl rate, crawl latency, crawl freshness, content
processing, CPU and memory load, continuous crawls, and the crawl queue.
Incorrect answers:
Not A: Microsoft Search Server performance counters would not provide any crawl data.
Not B: The crawl log would not provide such detailed information. The crawl log tracks information about the
status of crawled content. The log includes views for content sources, hosts, errors, databases, URLs, and
history.
Not D: ULS logs would not provide any crawl data. Best practices for crawling in SharePoint Server 2013
https://technet.microsoft.com/en-us/library/dn535606.aspx#BKMK_UseCrawlLog