Load-from-h2 failure with Galera

Toma · May 2, 2022, 9:04am

Hi. I got weird error when migrating metabase app DB from H2 to mariaDB.
Could anyone support and share insights how to resolve it ... ?

What happened?

Got error message "ERROR Re-enabling DB constraints...".

2022-05-02 17:05:17,301 INFO db.setup :: Database Migrations Current ...  ✅
Database setup took 21.1 s
2022-05-02 17:05:17,302 INFO cmd.copy :: [OK]
2022-05-02 17:05:17,303 INFO cmd.copy :: Testing if target mysql database is already populated...
2022-05-02 17:05:17,314 INFO cmd.copy :: [OK]
2022-05-02 17:05:17,327 INFO cmd.copy :: Temporarily disabling DB constraints...
2022-05-02 17:05:17,331 INFO cmd.copy :: [OK]
2022-05-02 17:05:17,338 INFO cmd.copy :: Copying instances of Database...
2022-05-02 17:05:17,364 ERROR cmd.copy :: BatchUpdateException:
 Message: (conn=928490) unexpected end of stream, read 0 bytes from 4 (socket was closed by server)
 SQLState: 08000
 Error Code: 0

2022-05-02 17:05:17,365 INFO cmd.copy :: Re-enabling DB constraints...
2022-05-02 17:05:17,365 ERROR cmd.copy :: [FAIL]

Command failed with exception: Rollback failed handling "ERROR Re-enabling DB constraints..."

The errored code looks here.

github.com

metabase/metabase/blob/19beda53393ef761ef57ea7dbb5474f6f4d57dd2/src/metabase/cmd/copy.clj#L232


(defmethod reenable-db-constraints! :h2
  [_ conn]
  (jdbc/execute! conn "SET REFERENTIAL_INTEGRITY TRUE"))


(defn- do-with-disabled-db-constraints [db-type conn f]
  (step (trs "Temporarily disabling DB constraints...")
    (disable-db-constraints! db-type conn))
  (try
    (f)
    (finally
      (step (trs "Re-enabling DB constraints...")
        (reenable-db-constraints! db-type conn)))))


(defmacro ^:private with-disabled-db-constraints
  "Disable foreign key constraints for the duration of `body`."
  {:style/indent 2}
  [db-type conn & body]
  `(do-with-disabled-db-constraints ~db-type ~conn (fn [] ~@body)))


(defn- clear-existing-rows!
  "Make sure the target database is empty -- rows created by migrations (such as the magic permissions groups and

When it happened?

Running java -Dlog4j2.debug=true -jar ~/metabase.jar load-from-h2 ./metabase.db

Detail system info

Version of metabase generating source H2 file ( metabase.db.mv.db )
v0.32.9

Version of metabase.jar

v0.32.9 -> failed
v0.42.3 -> failed
v0.42.4 -> failed

Destination Database : MariaDB Galera Cluster ( version 10.5.12 )

Connection URI ( Tried the parametes part with/without combinations. Nothing resolved.)
MB_DB_CONNECTION_URI='jdbc:mysql://{DBHOST}:{DBPORT}/metabase?user={DBUSER}&password={DBPASS}&characterEncoding=UTF-8&elideSetAutoCommits=true&useMysqlMetadata=true&usePipelineAuth=false'

flamber · May 2, 2022, 9:16am

Hi @Toma
Metabase currently doesn't support Galera officially, so perhaps it's something to do with that.
Try loading into a "regular" MariaDB, and then you can copy the data to Galera after that.
Also, do not try to upgrade and migrate at the same time:
https://www.metabase.com/docs/latest/operations-guide/migrating-from-h2.html#avoid-migrating-and-upgrading-at-the-same-time