> Am 13.11.2017 um 08:11 schrieb Dridi Boukelmoune <[email protected]>: > > On Sat, Nov 11, 2017 at 9:48 PM, <[email protected]> wrote: >> I was observing a behavior of a PHP script on one backend server that got >> executed/requested >> twice (but not by the client/browser). >> >> The plain script just processes data and only outputs a response until its >> done. The observed >> behavior is; when first_byte_timeout passes but the script is still >> processing data, the varnish >> node answers with an 503 and the script gets listed twice in the webserver >> process list. So, either >> it gets requested on this event again or the TCP connection close triggers >> an new execution. In any >> case its a bug and because of missing resources to dive into a more deeper >> analyses, I just disabled >> the enabled keep-alive option of the backend webserver (apache/httpd). The >> results: it helped to avoid >> a further execution of the script. >> >> The question is: What is the best practice to configure the backend >> webservers? Do you keep the >> keep-alive option enabled or not? >> >> I'd appreciate hearing your suggestions. > > I think you're getting a retry from varnishd, independent from VCL's > return(retry) which only happens on GET/HEAD requests that are > supposed to be side-effect-free and safely retry-able. On top of that > you might be hitting a bug where Varnish retries more than once. > Seeing some log would help confirm this hypothesis. > > https://github.com/varnishcache/varnish-cache/pull/2135
Ah, okay. Is this still valid for version 5.1/5.2? The mentioned script doesn't exist anymore. I will try to spend some time to reconstruct this case. -- Thanks, Leon _______________________________________________ varnish-misc mailing list [email protected] https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc
