Mysql collation


we are migrating Percona xtraDB cluster 5.7.x to Percona xtraDB cluster  8.0.19, and we want to make sure that both server has the same collation ! 
1) can we check both side’s collation?
2) if collation is different , is it possible to change collation without reinstall percona xtraDB cluster?
3) how to change collation to the same one if no need to reinstall mysql
4) if need to reinstall percona xtraDB cluster , how to make it install in the collation we want, seems only possible during bootstrap ?

Hi, I can see that you have a lot of questions about updating MySQL.We have recently released the online course “How to Upgrade to MySQL 8.0”.
Perhaps it can help you find answers to some questions.