On Thu, Jul 13, 2023 at 9:46 AM Luca Gervasi <[email protected]> wrote: > > Hi, > i'm helping to fix some issues with cookies (number, length...) thus I need > to dump all the cookies in every request (tied with the host header). I tried > with varnishlog but the actual value is limited (in our configuration) to ~ > 700 bytes by the vsl_reclen parameter, I suppose. Reading the documentation, > that value ranges between 16b and 4084b, which is lower than what I need to > dump the full monster cookie (~ 24kb).
This limit is actually dynamic and better reflected in the reference manual for vsl_buffer and vsl_reclen: https://varnish-cache.org/docs/7.3/reference/varnishd.html#vsl-buffer https://varnish-cache.org/docs/7.3/reference/varnishd.html#vsl-reclen If you want to increase reclen to 24kB, it first needs to fit inside a VSL buffer. In your case I would recommend bumping vsl_buffer to at least 64kB, and add 64kB to workspace_client and workspace_backend too (the VSL buffer lives on these workspaces). > At the moment I'm using tcpdump in the proxy port, but it is really > impractical as I have to grep/awk and group the requests...and I'm not really > proud about its manutenablity. > > Is there a way to dump, for every request that contains the cookie header, > such header plus others? (in my case: host)? https://varnish-cache.org/docs/7.3/reference/vsl-query.html > I was thinking about tapping into varnish functions using eBPF. What do you > think? Do you have something already working for my case that I could tamper > with? Try bumping vsl_buffer and vsl_reclen first, eBPF is probably way overkill. Cheers, Dridi _______________________________________________ varnish-misc mailing list [email protected] https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc
