很抱歉，这个问题含糊不清。
我有一个使用apahce2 php7.2，mysql 5.6运行Ubuntu 18.04的ec2实例。
这大约每25-30分钟发生一次：
Mar 11 03:01:45 ip-redacted systemd-resolved: Positive Trust Anchors:
Mar 11 03:01:45 ip-redacted systemd-resolved: . IN DS 19036 8 2 49aac11d7b6f6446702e54a1607371607a1a41855200fd2ce1cdde32f24e8fb5
Mar 11 03:01:45 ip-redacted systemd-resolved: . IN DS 20326 8 2 e06d44b80b8f1d39a95c0b0d7c65d08458e880409bbc683457104237c7f8ec8d
Mar 11 03:01:45 ip-redacted systemd-resolved: Negative trust anchors: 10.in-addr.arpa 16.172.in-addr.arpa 17.172.in-addr.arpa 18.172.in-addr.arpa 19.172.in-addr.arpa 20.172.in-addr.arpa 21.172.in-addr.arpa 22.172.in-addr.arpa 23.172.in-addr.arpa 24.172.in-addr.arpa 25.172.in-addr.arpa 26.172.in-addr.arpa 27.172.in-addr.arpa 28.172.in-addr.arpa 29.172.in-addr.arpa 30.172.in-addr.arpa 31.172.in-addr.arpa 168.192.in-addr.arpa d.f.ip6.arpa corp home internal intranet lan local private test
Mar 11 03:01:45 ip-redacted systemd-resolved: Using system hostname 'ip-redacted'.
Mar 11 03:01:45 ip-redacted systemd: Started Network Name Resolution.
Mar 11 03:01:45 ip-redacted systemd: Starting resolvconf-pull-resolved.service...
Mar 11 03:01:45 ip-redacted dhclient: bound to 172.30.2.224 -- renewal in 1659 seconds.
Mar 11 03:01:45 ip-redacted systemd: Started resolvconf-pull-resolved.service.
我认为这影响到前一天运行的cron，并且我认为这是经常导致客户端无法连接数据库（AWS RDS）的错误的根本原因。
是否需要每30分钟左右发生一次？我可以禁用它还是仅在影响用户的可能性很小的时候这样做？
感谢您提供的任何帮助，更多信息，随时发表评论。