On Wednesday, April 10, 2019 7:57 PM, Aki Tuomi <aki.tuomi at open-xchange.com> wrote:> > On 10 April 2019 21:26 Laura Smith via dovecot dovecot at dovecot.org wrote: > > ==> > dsync(foobar at example.com): Error: imapc(foobar.example.com:993): dns_lookup(foobar.example.com) failed: read(/var/run/dovecot/dns-client) failed: read(size=512) failed: Connection reset by peer > > This is dovecot's internal dns-client, and something goes wrong when talking to the service. > > > dsync(foobar at example.com): Error: Failed to initialize user: imapc: Login to foobar.example.com failed: Disconnected from server > > This is btw dsync service, not imap service. > > > ==> > Initially I thought "oh no, not another AppArmor block". > > But then surely the second message would not appear if the DNS lookup was not successful ? > > Also "dig foobar.example.com" works fine. > > How should I be troubleshooting this ? And if it is still likely to be AppArmor, what is calling it ? "doveadm" itself or something else ? What does "/var/run/dovecot/dns-client" do and why doesn't dovecot use standard OS calls like everyone else ? > > Because the "standard OS call" is blocking and we would prefer it to not block everything else. > > > So many questions ! > > AkiThanks for your reply, but both those message are generated from a simple : doveadm -v -o mail_fsync=never backup -R -u foobar at example.com imapc: So I don't know what you mean about dsync service failing ? Surely the DNS lookup succeeded if the 'dsync service' failed due to remote disconnect ? I'm still none the wiser as to where to start looking for troubleshoting ?
> On 10 April 2019 22:13 Laura Smith via dovecot <dovecot at dovecot.org> wrote: > > > On Wednesday, April 10, 2019 7:57 PM, Aki Tuomi <aki.tuomi at open-xchange.com> wrote: > > > > On 10 April 2019 21:26 Laura Smith via dovecot dovecot at dovecot.org wrote: > > > ==> > > dsync(foobar at example.com): Error: imapc(foobar.example.com:993): dns_lookup(foobar.example.com) failed: read(/var/run/dovecot/dns-client) failed: read(size=512) failed: Connection reset by peer > > > > This is dovecot's internal dns-client, and something goes wrong when talking to the service. > > > > > dsync(foobar at example.com): Error: Failed to initialize user: imapc: Login to foobar.example.com failed: Disconnected from server > > > > This is btw dsync service, not imap service. > > > > > ==> > > Initially I thought "oh no, not another AppArmor block". > > > But then surely the second message would not appear if the DNS lookup was not successful ? > > > Also "dig foobar.example.com" works fine. > > > How should I be troubleshooting this ? And if it is still likely to be AppArmor, what is calling it ? "doveadm" itself or something else ? What does "/var/run/dovecot/dns-client" do and why doesn't dovecot use standard OS calls like everyone else ? > > > > Because the "standard OS call" is blocking and we would prefer it to not block everything else. > > > > > So many questions ! > > > > Aki > > > Thanks for your reply, but both those message are generated from a simple : > doveadm -v -o mail_fsync=never backup -R -u foobar at example.com imapc: > > So I don't know what you mean about dsync service failing ? Surely the DNS lookup succeeded if the 'dsync service' failed due to remote disconnect ? > > I'm still none the wiser as to where to start looking for troubleshoting ?Did you check dovecot logs? Maybe there is something useful? Aki
Sent with ProtonMail Secure Email. ??????? Original Message ??????? On Wednesday, April 10, 2019 8:20 PM, Aki Tuomi <aki.tuomi at open-xchange.com> wrote:> > On 10 April 2019 22:13 Laura Smith via dovecot dovecot at dovecot.org wrote: > > On Wednesday, April 10, 2019 7:57 PM, Aki Tuomi aki.tuomi at open-xchange.com wrote: > > > > > > On 10 April 2019 21:26 Laura Smith via dovecot dovecot at dovecot.org wrote: > > > > > > > > =========================================================================> > > > > > > > dsync(foobar at example.com): Error: imapc(foobar.example.com:993): dns_lookup(foobar.example.com) failed: read(/var/run/dovecot/dns-client) failed: read(size=512) failed: Connection reset by peer > > > > > > This is dovecot's internal dns-client, and something goes wrong when talking to the service. > > > > > > > dsync(foobar at example.com): Error: Failed to initialize user: imapc: Login to foobar.example.com failed: Disconnected from server > > > > > > This is btw dsync service, not imap service. > > > > > > > ==> > > > Initially I thought "oh no, not another AppArmor block". > > > > But then surely the second message would not appear if the DNS lookup was not successful ? > > > > Also "dig foobar.example.com" works fine. > > > > How should I be troubleshooting this ? And if it is still likely to be AppArmor, what is calling it ? "doveadm" itself or something else ? What does "/var/run/dovecot/dns-client" do and why doesn't dovecot use standard OS calls like everyone else ? > > > > > > Because the "standard OS call" is blocking and we would prefer it to not block everything else. > > > > > > > So many questions ! > > > > > > Aki > > > > Thanks for your reply, but both those message are generated from a simple : > > doveadm -v -o mail_fsync=never backup -R -u foobar at example.com imapc: > > So I don't know what you mean about dsync service failing ? Surely the DNS lookup succeeded if the 'dsync service' failed due to remote disconnect ? > > I'm still none the wiser as to where to start looking for troubleshoting ? > > Did you check dovecot logs? Maybe there is something useful? > > AkiOnly the same old cryptic message about dns-client ? master: Fatal: execv(/usr/lib/dovecot/dns-client) failed: Permission denied master: Error: service(dns_client): command startup failed, throttling for 16 secs dns_client: Fatal: master: service(dns_client): child 14293 returned error 84 (exec() failed)