Poul-Henning Kamp wrote: > The critical question is how we define "backend is down" and how > fast and efficient we can detect it. > > Ideas for how to express it in VCL are very welcome.
Maybe naive: # First, we setup decide how to "sniff" that a backend is down # # options_ping: Send a HTTP OPTIONS (Perlbal does that) # timeout: If the backend does not answer within x seconds, it is # probably down # icp: Abuse the protocol. (Squid + Zope does that) backend.down_protocol = options_ping | timeout | icp # What is the timeout limit? backend.timeout = 30 # How long time should the backend be marked as "down" before we try # again? backend.retry_after = 300 # And then just use it if(backend.down).... /Anton Stonor _______________________________________________ varnish-misc mailing list [email protected] http://projects.linpro.no/mailman/listinfo/varnish-misc
