vcl_recv vcl_pipe vcl_pass vcl_hash vcl_hit vcl_miss vcl_fetch vcl_deliver vcl_init vcl_fini vcl_error if else elsif elseif set call error esi include remove unset panic rollback purge synthetic hash_data regsub regsuball ban ban_url deliver error fetch hash hit_for_pass lookup ok pass pipe restart random client hash round-robin dns fallback std example abtest threescale authentication boltsort crashhandler curl digest dns header memcached null querystring shield softpurge statsd throttle timeutils urlcode var timers