[Pdns-users] powerdns frequently crashes and restarts

[Riccardo Brunetti]

Hello again.

Thanks for your suggestion.

I changed the configuration from primary=yes to primary=no and the problem seems to be resolved.



I though it was enough to set:

only_notify = 

notify_also =



to avoid the notification process.



Thank you again for the support.

Riccardo


18/02/2022, 10:28 Klaus Darilion ha scritto:


> So, when a zone gets updated, PowerDNS checks if it has to notify slaves and send NOTIFYs to the slaves. Once this is done, it updates the notified_serial in the domains table. This UPDATE, for whatever reason, causes a deadlock.
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> Maybe you can work around that problem. You mentioned that you use DB replication. So, if all the slaves get their zones via DB replication and NOT via NOTIFY/AXFR, then you can disable the NOTIFYs and "UPDATE notified_serial...." query by setting master=no in pdns.conf.
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> So, if Powerdns need not send NOTIFYs, then set master=no.
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> regards
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> Klaus
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> Von: Pdns-users <pdns-users-bounces at mailman.powerdns.com> Im Auftrag von Klaus Darilion via Pdns-users
> Gesendet: Freitag, 18. Februar 2022 09:58
> An: Riccardo Brunetti <riccardo.brunetti at host.it>; Pdns-users at mailman.powerdns.com
> Betreff: Re: [Pdns-users] powerdns frequently crashes and restarts
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> Look in the mysql-server log. Maybe it mentions which other transaction causes the deadlock. That my help to find the cause.
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> Is this problem something new? I.e. started it after a PDNs or Mysql Upgrade?
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> regards
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> Klaus
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> Von: Pdns-users <pdns-users-bounces at mailman.powerdns.com> Im Auftrag von Riccardo Brunetti via Pdns-users
> Gesendet: Freitag, 18. Februar 2022 09:55
> An: pdns-users at mailman.powerdns.com
> Betreff: [Pdns-users] powerdns frequently crashes and restarts
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> Hello.
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> We are having quite frequent crashes of our pdns server with the following syslog messages:
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> > Feb 17 13:39:33 xxxx.xxxxx.xxx.xxxx pdns_server[26672]: Exiting because communicator thread died with error: GSQLBackend unable to refresh domain_id XXXXX: Could not execute mysql statement: update domains set notified_serial=? where id=?: Deadlock found when trying to get lock; try restarting transaction
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> > Feb 17 13:39:34 xxxx.xxxxx.xxx.xxxx systemd[1]: pdns.service: main process exited, code=exited, status=1/FAILURE
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> > Feb 17 13:39:34 xxxx.xxxxx.xxx.xxxx systemd[1]: Unit pdns.service entered failed state.
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> > Feb 17 13:39:34 xxxx.xxxxx.xxx.xxxx systemd[1]: pdns.service failed.
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> > Feb 17 13:39:35 xxxx.xxxxx.xxx.xxxx systemd[1]: pdns.service holdoff time over, scheduling restart.
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> > Feb 17 13:39:35 xxxx.xxxxx.xxx.xxxx systemd[1]: Stopped PowerDNS Authoritative Server.
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> > Feb 17 13:39:35 xxxx.xxxxx.xxx.xxxx systemd[1]: Starting PowerDNS Authoritative Server...
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> > Feb 17 13:39:35 xxxx.xxxxx.xxx.xxxx pdns_server[25899]: Loading '/usr/lib64/pdns/libgmysqlbackend.so'
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> > Feb 17 13:39:35 xxxx.xxxxx.xxx.xxxx pdns_server[25899]: This is a standalone pdns
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> I don't know if this can be related, but just before those crashes we see messages like:
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> > Feb 17 13:39:32 xxxx.xxxxx.xxx.xxxx pdns_server[26672]: Request to queue notification for domain yyyyy.yy was processed, but no valid nameserver or ALSO-NOTIFYs found. Not notifying!
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> Just to mention briefly our setup: we are running:
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> PowerDNS Authoritative Server 4.5.2 (C)
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> in a percona mysql cluster with three nodes, each node having it's own mysql and pdns server (in order to have redundancy of database and APIs).
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> This cluster acts as a "backend master" for the real authoritative slaves, placed elsewhere, replicating the db.
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> Can you help us to understand why we have those crashes?
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> Thanks
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> Riccardo
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