Since the release of Group Replication, one of its main security features is IP Address Whitelisting. This allows us to control whoever can send requests to enter in a group.
On MySQL version 8.0.4, we added a new possibility that it was lacking since the beginning: the ability to configure IP Address Whitelisting with hostnames. All other communication specific parameters like Local Address and Seeds could be configured with hostnames, except Whitelisting. This opens a range of possibilities if your system is built around IP Pools that make a machine address vary in every restart since. This is a somewhat common scenario in Virtual Machines deployments. With this new mechanism, you just need to allow a machine with a certain hostname to enter the group!
How to use it!
This builds on top of the current configuration possibilities. You can mix-and-match every possible value in a whitelist: IPs, IPs with Network Masks, Hostnames, and Hostnames with Network Masks.
You can check more details about it in the official MySQL documentation.
Go and try out MySQL 8.0.4. It is not generally available yet, thus not production ready, so use it at your own risk, but we would love to hear your thoughts, comments, and experiences with this release candidate. You can reach us through bug reports, feature requests, the replication mailing list or by just leaving a comment on this blog post.