Server version: 10.5.16-MariaDB-1:10.5.16+maria~bullseye-log



An upgrade from 10.5.16-MariaDB-1:10.5.16+maria~buster-log to 10.5.16-MariaDB-1:10.5.16+maria~bullseye-log (buster to bullseye move) breaks mariabackup SST. The attempt to bootstrap a new cluster and adding another node to the cluster gives the below error on the joiner 


Jun 27 16:56:51 2022-06-27 16:56:51 1 [ERROR] WSREP: Failed to prepare for 'mariabackup' SST. Unrecoverable.

Jun 27 16:56:51 2022-06-27 16:56:51 1 [ERROR] WSREP: SST request callback failed. This is unrecoverable, restart required.


In the donor node’s syslog, below error is seen:


E Failed to set SNI host ""



Further investigation revealed that socat 1.7.4 (recently updated in Debian bullseye) defaults to using Server Name Indication (SNI) which breaks epoptes use of socat (https://github.com/epoptes/epoptes/issues/127) leading to failure of mariabackup SST on Bullseye.

 We resolved the issue by adding the no-sni option to the wsrep_sst_mariabackup script.

if [ $encrypt -lt 2 ]; then

            if [ "$WSREP_SST_OPT_ROLE" = 'joiner' ]; then

                tcmd="socat -u TCP-LISTEN:$SST_PORT,reuseaddr$sockopt stdio"

            else

                tcmd="socat -u stdio TCP:$REMOTEIP:$SST_PORT$sockopt,no-sni=1"

            fi

            return

        fi

In the hope that it may help others in the community, we're opening this bug report.