Re: Repeated 'refresh'es may cause excessive DNS queries
Miroslav Lichvar <[email protected]>
| Newsgroups | gmane.comp.time.chrony.user |
|---|---|
| Message-ID | <ZfB8mpYIdIrXfOc9@localhost> |
On Tue, Mar 12, 2024 at 04:35:59PM +0100, [email protected] wrote: > STEPS TO REPRODUCE: > 1) Install a DNS server on machine A (can also be a VM) and configure it to > always reply with a TTL of 0 for certain domains. This can be accomplished with > dnsmasq and a hardcoded entry in /etc/hosts for, say, 2.europe.pool.ntp.org: > > > cat /etc/hosts > # HACK for testing: use ptbtime1.ptb.de as source > 192.53.103.108 2.europe.pool.ntp.org > [snip] > > 2) On machine B, point the local DNS resolver to machine A. > Install chrony and configure it to use only the source from step 1. > > > cat /etc/chrony/chrony.conf > pool 2.europe.pool.ntp.org minpoll 10 iburst > [snip] > > 3) Repeatedly issue "chronyc refresh" commands on machine B and watch the sparks > (and the DNS queries) fly. That seems to be working for me as expected. I see one request per refresh. Can you please build chronyd with --enable-debug and post the chronyd -dd output for first few refresh commands? -- Miroslav Lichvar -- To unsubscribe email chrony-users-request-kWFZVVI9zxvPqho9SqqRMmD2FQJk+8+b@public.gmane.org with "unsubscribe" in the subject. For help email chrony-users-request-kWFZVVI9zxvPqho9SqqRMmD2FQJk+8+b@public.gmane.org with "help" in the subject. Trouble? Email [email protected]