[Pdns-users] TCP nameserver had error, cycling backend: innodb-read-committed=no
kjansen at wijhosten.nl
kjansen at wijhosten.nl
Sat Jan 9 13:42:01 UTC 2021
I am running against an issue i like to fix.
So now and then we are getting the following error in the logs:
TCP nameserver had error, cycling backend: Unable to launch gmysql
connection: Please add '(gmysql-)innodb-read-committed=no' to your
PowerDNS configuration, and reconsider your storage engine if it does
not support transactions.
At that exact moment we are getting a error report from Neustar with the
Premature closure of connection.
I have a PowerDNS 4.1.14 Authorive (hidden master server) (Debian9)
- VPS 6 cores, 16gb ram.
MariaDB 10.1.44 (Debian 9)
- VPS 8 cores, 8gb ram
allow-axfr-ips=188.8.131.52, 184.108.40.206, 220.127.116.11,
18.104.22.168, 22.214.171.124, 126.96.36.199, 188.8.131.52,
184.108.40.206, 220.127.116.11, 18.104.22.168, 22.214.171.124
only-notify=126.96.36.199, 188.8.131.52, 184.108.40.206
also-notify=220.127.116.11, 18.104.22.168, 22.214.171.124
MariaDB Config: (Default with the following adjustments)
innodb_buffer_pool_size = 4G
innodb_log_file_size = 1G
innodb_buffer_pool_instances = 1
key_buffer_size = 16M
max_allowed_packet = 16M
thread_stack = 192K
thread_cache_size = 8
myisam_recover_options = BACKUP
max_connections = 5000
query_cache_limit = 1M
query_cache_size = 16M
mysql > status:
Threads: 15 Questions: 342316599 Slow queries: 0 Opens: 188 Flush
tables: 1 Open tables: 182 Queries per second avg: 6897.372
Nobody is doing a lookup on this server, its completly hidden from the
internet, and only open for Neustar to do AXFR/IXFR requests:
Jan 9 14:28:52 hidden-master pdns: AXFR of domain 'example.com'
allowed: client IP 126.96.36.199 is in allow-axfr-ips
Jan 9 14:28:52 hidden-master pdns: gmysql Connection successful.
Connected to database 'database' on '10.21.0.254'.
Jan 9 14:28:52 hidden-master pdns: IXFR of domain 'example.com'
to 188.8.131.52 finished
Thats why i think the mysql server has around 7k query's since we are
running almost 800k domains on this server.
An error in the log:
Jan 9 13:00:21 hidden-master pdns: gmysql Connection failed:
Please add '(gmysql-)innodb-read-committed=no' to your PowerDNS
configuration, and reconsider your storage engine if it does not support
Jan 9 13:00:21 hidden-master pdns: Caught an exception
instantiating a backend: Unable to launch gmysql connection: Please add
'(gmysql-)innodb-read-committed=no' to your PowerDNS configuration, and
reconsider your storage engine if it does not support transactions.:
Jan 9 13:00:21 hidden-master pdns: Cleaning up
Are we asking too much from Powerdns? Do we have a misconfiguration? Or
can we adjust some settings to avoid this problem?
Changing the config from "yes" to "no" does not solve the issue, it
feels it even makes it worse.
No errors shown in /var/log/myql/error.log
I think we are hitting a cap somewhere.
Any help and or advice is welcome.
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