Hello!
Today we published release 4.5.3 of the Authoritative Server. It contains several robustness fixes for the LMDB backend, and for the zone cache.
Please find a full list in the changelog.
Please make sure to read the Upgrade Notes before upgrading.
The tarball (signature) is available at downloads.powerdns.com and packages for various Linux distributions are available from repo.powerdns.com.
Please send us all feedback and issues you might have via the mailing list, or in case of a bug, via GitHub.