MySQL 5.7.12 import cannot create a JSON value from a string with CHARACTER SET 'binary'

Question

I exported my database with JSON columns in it. After I migrated to a new server, my import crashed every time with an error like:

cannot create a JSO

Answer 1

This odd issue was occurring when running a simple UPDATE query:

update some_table set json_attr = '{"test":168}' where id = 123456;

Restarting MySQL fixed it. Was not able to pinpoint the cause.

Edit: We are using Aurora. It looks like it was related to us having a weird configuration where the same instance handled both master & slave/reader connections.