Hello,
I'm running unbound 1.16.1 on Linux 5.15.55, configured to forward
everything over TCP TLS connections.
Despite keepalive being enabled, I can see that the connections get
closed early.
Note that the server is not busy at all.
Here are the relevant bits of the configuration:
forward-zone:
name: "."
forward-tls-upstream: yes
forward-addr: 1.1.1.1@853#cloudflare-dns.com
forward-addr: 1.0.0.1@853#cloudflare-dns.com
forward-addr: 8.8.8.8@853#dns.google
forward-addr: 8.8.4.4@853#dns.google
max-reuse-tcp-queries: 2000
tcp-idle-timeout: 9000000
edns-tcp-keepalive: yes
edns-tcp-keepalive-timeout: 9000000
num-threads: 1
Packet captures show that after as few as ~30 seconds, unbound sends a
FIN+ACK. Sometimes it sends a couple more RST packets which doesn't seem
right either.
This, combined with the behavior that unbound wants to open connections
to all upstream servers instead of reusing existing connections, it will
constantly open new connections (and to make matters worse it does not
seem to do that in the background but synchronously with incoming
queries, blocking them) leads to many queries being needlessly delayed
by about 80 to 180ms.
Did I do something wrong? How can I fix this?
