Re: Error 1064 Duplicate entry 'ndbcluster-96' for key 'tables.engine'

[Magnus Blåudd]

Hi Tony,

this indicates a problem with the MySQL data dictionary being out of sync with the dictionary in NDB. Basically I would explain it as the MySQL data dictionary being a "cache" which holds a set of system tables (stored in InnoDB) with rows for each table and other objects in NDB. In particular there is a "tables" table which has a unique key on engine_name+engine_id. There is a collision on that unique key and thus the NDB table can be created in NDB but can't be installed in the MySQL data dictionary.


This should be fixed in 8.0.33 as:

"The existing mysqld definition is dropped by name, thus removing the unique ndbcluster-ID key in the MySQL data dictionary but the new table ID could also already be occupied by another (stale) definition. The resulting mistmatch prevented setup of the binary log.

To fix this problem we now explicitly drop any ndbcluster-ID definitions that might clash in such cases with the table being installed. (Bug #34733051)"

https://dev.mysql.com/doc/relnotes/mysql-cluster/8.0/en/news-8-0-33.html

/ Magnus