rbtdb.c:1497: fatal error

Summary

After days running bind it suddenly crashes and stops. When looking at the logs we encounter an rbtdb.c fatal error.

BIND version used

BIND 9.11.5 (Extended Support Version) id:3b0b204 running on Linux x86_64 3.10.0-862.14.4.el7.x86_64 #1 SMP Wed Sep 26 15:12:11 UTC 2018 built by make with '--enable-threads' '--enable-largefile' '--disable-ipv6' '--with-tuning=large' compiled by GCC 4.8.5 20150623 (Red Hat 4.8.5-28) compiled with OpenSSL version: OpenSSL 1.0.2k 26 Jan 2017 linked to OpenSSL version: OpenSSL 1.0.2k-fips 26 Jan 2017 compiled with zlib version: 1.2.7 linked to zlib version: 1.2.7 threads support is enabled

Steps to reproduce

No steps in particular. Just running and receiving high DNS traffic.

What is the current bug behavior?

Service exits completely.

What is the expected correct behavior?

Service to continue to run without interruptions.

Relevant configuration files

Options in named.conf:

options {
      directory       "/conf";
      dnssec-validation auto;
      auth-nxdomain no;
      pid-file        "/var/run/named.pid";
      statistics-file "/var/run/named.stats";
      dump-file       "/var/run/named.db";
      version         "[secured]";
      tcp-clients     1500;

// only allow recursion from authorized addresses
      allow-recursion { coqui-prt; private; };

      listen-on port 53 { 10.10.220.100; };

// set the maximum recursive queries by clients
      recursive-clients 95000;
};

Relevant logs and/or screenshots

Dec  2 16:04:20 wdnscache2 named[8617]: rbtdb.c:1497: fatal error:
Dec  2 16:04:20 wdnscache2 named[8617]: RUNTIME_CHECK(rbtdb->next_serial != 0) failed
Dec  2 16:04:20 wdnscache2 named[8617]: exiting (due to fatal error in library)

Possible fixes

None yet. Just start service and it continues.