On Mon, Aug 26, 2013 at 12:23 PM, Matthew Walker mwalker@wikimedia.orgwrote:
Whist investigating an orthogonal logging issue I encountered a couple of differences between squid/varnish which I didn't know about:
- Varnish does not give subsecond request time information
- Varnish does give subsecond request processing time info
- Varnish calls it 'hit/200' or 'miss/302' instead of 'TCP_MEM_HIT/200' or
'TCP_MISS/302'
All correct. Note that caching information from this field isn't very useful regardless of if its coming from squid or varnish, on account of being logged from the frontend routing instance, despite most cache hits come from the backend. The field is mostly just useful for the status code, though varnish states like pass may be of interest at times as well.
- Varnish does not URL encode the user agent field
Example log lines: amssq41.esams.wikimedia.org 1013692039 2013-07-31T23:00:02.331 0 XXX TCP_MEM_HIT/200 614 GET http://meta.wikimedia.org/XXX NONE/- image/png http://en.wikipedia.org/XXX - Mozilla/5.0%20(Wind... en-US en;q=0.8 - cp1006.eqiad.wmnet 1442176851 2013-07-31T23:00:02.452 0 XXX TCP_MISS/302 406 GET http://meta.wikimedia.org/XXX NONE/- - http://en.m.wikipedia.org/XXX - Mozilla/5.0%20(i.... en-us - cp3012.esams.wikimedia.org 823553992 2013-07-31T23:00:02 0.000119448 XXX hit/200 20 GET http://meta.m.wikimedia.org/XXX - image/png http://de.m.wikipedia.org/XXX XXX Mozilla/5.0 (iPho... de-de -
~Matt Walker Wikimedia Foundation Fundraising Technology Team
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