List contents of varnish cache

varnish

Is there a way to list the contents of the varnish cache storage? Also, it would be nice to somehow list the most frequent cache hits.

I found a way to see the most frequent cache misses by listing what is being sent to the backend with:

varnishtop -b -i TxURL

It would be very useful to see what are my top cache hits URLs.

Best Answer

This answer was originally posted on stackoverflow, and I think it is quite helpful: https://stackoverflow.com/questions/14214104/list-contents-of-varnish-cache

You can use the parameter "Varnish:hitmiss" of varnishncsa.

First capture a sample of logs with:

varnishncsa -F '%U%q %{Varnish:hitmiss}x' -n NAME -w /path/requests.logs

and then:

sort -k 1 /path/requests.logs | uniq -c | sort -k 1 -n -r | head -25

Related Solutions

How to Read a Varnish Histogram

So the x-axis is the time it takes for the request to come into varnish and get sent back to the client. The |'s are the cache hits and the #'s are the misses. So you should see all the |'s on the left since that is a faster time.

So the left most numbers are faster.. the right most are slower..

now the 1:2 n= number.. Its numbers for the vertical scale and sample size. I wouldn't worry much about those.

But from that output.. you have a pretty fast cache going on.

Truncated headers from varnish configuration file

Take look on vcl_deliver, you see next condition here

if (resp.http.X-Cache-Debug) {
        # debug headers
} else {
        # remove Varnish/proxy header
}

So, my question is: are you sure that your application sets X-Cache-Debug header? If not, you need to take care about it or modify VCL with removing this condition (and "# remove Varnish/proxy header" part too)

Best Answer

Related Solutions

How to Read a Varnish Histogram

Truncated headers from varnish configuration file

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