MySQL 8.0.20 support?

MySQL & MariaDB Percona Server for MySQL 8.0
1

Hi all, 
we updated our MySQL servers to the latest 8.0.20 version. From change notes: 

Now when we run our backup, it fails with this error: 
``` Using server version 8.0.20 xtrabackup: uses posix_fadvise(). xtrabackup: cd to /var/lib/mysql xtrabackup: open files limit requested 0, set to 1024 xtrabackup: using the following InnoDB configuration: xtrabackup: innodb_data_home_dir = . xtrabackup: innodb_data_file_path = ibdata1:12M:autoextend xtrabackup: innodb_log_group_home_dir = ./ xtrabackup: innodb_log_files_in_group = 2 xtrabackup: innodb_log_file_size = 1073741824 Number of pools: 1 Unknown redo log format (4). Please follow the instructions at http://dev.mysql.com/doc/refman/8.0/en/ upgrading-downgrading.html. xtrabackup: Error: recv_find_max_checkpoint() failed.
``` Any ideas of workaround until new version of Xtrabackup? 
2

For anyone wondering, workaround for us was: 
1. Downgrade read only slave server to mysql 8.0.19 (basically drop 8.0.20 and download packages from https://repo.mysql.com/apt/ubuntu/pool/mysql-8.0/m/mysql-community/);
2. Restore the latest backup; 
3. Connect this one as read only replica again

make backups out of this replica server

3

There is a blog post here with a caution about downgrading on MySQL 8 MySQL 8 Minor Version Upgrades Are ONE-WAY Only - Percona Database Performance Blog
The next release of PXB will address this issue, but yes the redo logs in MySQL have to be dealt with for it to work.