Locating connection reset issue / h2 vs http/1.1

[info+varnish at shee.org]

Am 31.01.2019 um 17:38 schrieb Guillaume Quintard <guillaume at varnish-software.com>:
> 
> On Thu, Jan 31, 2019 at 6:22 AM <info+varnish at shee.org> wrote:
>> 
>> I have following stack: hitch-1.5 - varnish-5.2.0 - httpd-2.2/2.4
>> 
>> On a high traffic node I am observing a lot of "Socket error: Connection reset by peer" log entries coming from hitch.
>> 
>> I am trying to locate the cause of the issue (hitch or varnish site).
>> 
>> So far I can say; that disabling h2 on hitch the "Connection resets" doesn't appear anymore.
>> 
>> Does this have to do with varnish-5.2.'s h2 implementation?
>> 
>> Jan 30 19:02:37 srv-s01 hitch[4006]: ww.xx.yy.zz:59395 :0 10:11 NPN/ALPN protocol: h2
>> Jan 30 19:02:37 srv-s01 hitch[4006]: ww.xx.yy.zz:59395 :0 10:11 ssl end handshake
>> Jan 30 19:02:37 srv-s01 hitch[4006]: ww.xx.yy.zz:59395 :42884 10:11 backend connected
>> Jan 30 19:02:39 srv-s01 hitch[4006]: {backend} Socket error: Connection reset by peer
>> Jan 30 19:02:39 srv-s01 hitch[4006]: ww.xx.yy.zz:59395 :42884 10:11 proxy shutdown req=SHUTDOWN_CLEAR
>> Jan 30 19:02:39 srv-s01 hitch[4006]: {backend} Socket error: Broken pipe
>> Jan 30 19:02:39 srv-s01 hitch[4006]: ww.xx.yy.zz:59395 :42884 10:11 proxy shutdown req=SHUTDOWN_CLEAR
>> Jan 30 19:02:39 srv-s01 hitch[4006]: ww.xx.yy.zz:59399 :0 10:11 proxy connect
> 
> Have you activated h2 support in Varnish? (it's not on by default)
> 

Sure, DAEMON_OPTS has -p feature=+http2 passed. The content is delivered via h2 (verified in browsers) 
but sometimes lot of assets (client view) produce ERR_CONNECTION_CLOSED errors in the browser and on 
server site the mentioned "connection reset by peer" log entries appears ...

--
Leon