Once a client is reportedly gone, processing its VCL task(s) is just a waste of resources. The execution of client-facing VCL is intercepted and an artificial return(fail) is returned in that scenario. Thanks to the introduction of the universal return(fail) proper error handling and resource tear down is already in place, which makes this change safe modulus unknown bugs. This adds a circuit breaker anywhere in the client state machine where there is VCL execution. A new Reset time stamp is logged to convey when a task does not complete because the client is gone. This is a good complement to the walk away feature and its original circuit breaker for the waiting list, but this has not been integrated yet. While the request is technically failed, it won't increase the vcl_fail counter, and a new req_reset counter is incremented. This new behavior is guarded by a new vcl_req_reset feature flag, enabled by default. Refs varnishcache#3835 Refs 61a15cb Refs e5efc2c Refs ba54dc9 Refs 6f50a00 Refs b881699 Conflicts: bin/varnishd/cache/cache_vrt_vcl.c bin/varnishd/cache/cache_vcl_vrt.c bin/varnishd/mgt/mgt_param_bits.c include/tbl/params.h

Commits

Commits on Oct 18, 2023

vtc: mv t02025.vtc t02026.vtc

vtc: Avoid cycling the barrier in t02014

transport: New poll method

vcl_vrt: Skip VCL execution if the client is gone

http2_session: Implement transport polling

stevedore: Set up nuke_limit for buffer allocations