1701110 - Sites do not load with HTTP3 and DoH enabled

Status: RESOLVED DUPLICATE of bug 1700309

(Core :: Networking: HTTP, defect, P1)

Description

[Dragana Damjanovic [:dragana]]

This is a copy of bug 1700703 comment 5 :

I think this is the same bug. This is also regressed by bug 1699490.

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:89.0) Gecko/20100101 Firefox/89.0
Build ID: 20210325085523
Steps to reproduce
Preparation:

Use a new profile. Enable HTTP/3, DoH (use either provider) in Nightly.
Install uMatrix. Leave settings as default. uMatrix is optional but it amplifies the bug.
Visit https://lihkg.com/category/25 (a Chinese forum with a Cloudflare certificate). At uMatrix toolbar panel, allow ajax.cloudflare.com script to lihkg.com. Reload the tab.

Reproducing the bug:

In the page's left panel, click on a few threads to load them on the right panel. This is to ensure the site works properly and also prepare for the next steps
Click on any loaded thread in left panel. Then do not interact with the page.
Wait for about 1 minute to 1m10s.
Click on another loaded thread in left panel.

Actual result

The forum thread on step 7 does not load. On the right side on right panel, there is a forum notice popping out saying 線已斷, i.e. connection dropped.
If I keep clicking on other threads, more 線已斷 will be shown.

Notes

Without HTTP3 or DoH, I cannot reproduce the bug.
Without uMatrix, 線已斷 only occurs once. Connection is restored at 2nd click.
If I waited for too long at step 6, I cannot reproduce the bug.
After the bug occurs, it will resolve itself after letting the page idle for a few minutes. The bug will surface again if I follow step 5~7 again.
The bug can occur even without the waiting at step 6 but it is random. The STR above reproduces the bug 100% of the time, at least on my system.

Comment 1

[Dragana Damjanovic [:dragana]]

Can you make a http log:
https://developer.mozilla.org/en-US/docs/Mozilla/Debugging/HTTP_logging

Comment 2

[Dragana Damjanovic [:dragana]]

Can you try to set network.dns.use_https_rr_as_altsvc to false (got to about:config)?
Let me know if you can reproduce with that pref sett to false.

Comment 3

[Dragana Damjanovic [:dragana]]

We can reproduce this. No need for a log also it is not related o he pref from comment 2.

Comment 4

[Kershaw Chang [:kershaw]]

I think this is a dup of bug 1700309.

I see the same log:

2021-03-26 09:08:04.050158 UTC - [Parent 45238: Socket Thread]: V/nsHttp DnsAndConnectSocket::SetupDnsFlags [this=12a663ac0] 
2021-03-26 09:08:04.050175 UTC - [Parent 45238: Socket Thread]: D/nsHostResolver Resolving host [lihkg.com]<^partitionKey=%28https%2Clihkg.com%29> type 0. [this=124db6930]
2021-03-26 09:08:04.050187 UTC - [Parent 45238: Socket Thread]: D/nsHostResolver   Offline request for host [lihkg.com]; ignoring.
2021-03-26 09:08:04.050198 UTC - [Parent 45238: Socket Thread]: V/nsHttp Setting Socket to use IP hint address
2021-03-26 09:08:04.050206 UTC - [Parent 45238: Socket Thread]: V/nsHttp DnsAndConnectSocket::SetupDnsFlags flags=24576 flagsBackup=24608 [this=12a663ac0]
2021-03-26 09:08:04.050213 UTC - [Parent 45238: Socket Thread]: V/nsHttp DnsAndConnectSocket::SetupEvent state=0 event=0
2021-03-26 09:08:04.050221 UTC - [Parent 45238: Socket Thread]: V/nsHttp DnsAndConnectSocket::TransportSetup::ResolveHost [this=12a663b28 lihkg.com]
2021-03-26 09:08:04.050230 UTC - [Parent 45238: Socket Thread]: E/nsHttp nsHttpTransaction::OnSocketStatus [this=13815b000 status=804b0003 progress=0]
2021-03-26 09:08:04.050270 UTC - [Parent 45238: Socket Thread]: D/nsHostResolver Resolving host [lihkg.com]<^partitionKey=%28https%2Clihkg.com%29> type 0. [this=124db6930]
2021-03-26 09:08:04.050283 UTC - [Parent 45238: Socket Thread]: D/nsHostResolver   No usable record in cache for host [lihkg.com] type 0.
2021-03-26 09:08:04.050291 UTC - [Parent 45238: Socket Thread]: D/nsHostResolver NameLookup host:lihkg.com af:0
2021-03-26 09:08:04.050298 UTC - [Parent 45238: Socket Thread]: D/nsHostResolver Skip lookup if RES_IP_HINT is set
[Parent 45238, Socket Thread] WARNING: NS_ENSURE_SUCCESS(rv, rv) failed with result 0x804B001E (NS_ERROR_UNKNOWN_HOST): file /Users/changkershaw/work/central/netwerk/protocol/http/nsHttpConnectionMgr.cpp:1753

Comment 5

[Dragana Damjanovic [:dragana]]

Thanks Kershaw. This is looks like a dup of bug 1700309.