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I'm trying to understand this server log line from cache_access.log. What does each field represent, specifically why are there three IPs listed and what does each represent?

[HIT - - - -], ( - - [25/Apr/2014:00:30:02 +0000]  "GET /page/content HTTP/1.1" 200 1721 "" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/34.0.1847.116 Safari/537.36"
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This is the cache access log from which utility ? – Iain May 7 '14 at 19:54
Varnish, maybe? It's probably the client IP, the cache server IP, and the app server IP. – ceejayoz May 7 '14 at 19:54

From the date onwards it looks like a standard Apache combined format.

%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"

Can find what each field is here:

Not sure what the cache fields at the beginning are.

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How does %h have 3 different values in the example John has given? – Evan May 8 '14 at 16:32

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