Updates/Inserts frozen while index is being created on a DIFFERENT database

I ran into a issue that I just cant figure out. I am leveraging 5.7.31-34-57-log Percona XtraDB Cluster but this does not appear to be cluster related

Basically I have a quiet database table that has several million rows in it. I create a partial index on a text field (first 100 char) While this index creation is in progress updates and inserts on a totally different database are paused until the index creation is completed.

The reason I do not think that this is cluster related is I took the cluster down to a single node and was able to duplicate the issue

Why would a index creation on a table that very few people leverage impact updates on a table with no fk,triggers or events associated with the index creation

innodb_file_per_table | ON

Hi meyerder, unfortunately this is a known limitation of PXC/Galera clusters. DDL statements block the whole cluster in the default TOI mode. You can try running the change in a rolling fashion using RSU method or rely on external tool like pt-online-schema-change to avoid locking.

Check out the following https://www.percona.com/resources/webinars/how-avoid-pitfalls-schema-upgrade-percona-xtradb-cluster

Hope that helps