Hi, I have a few mysql cluster, previously on 5.5 (debian jessie) that we are upgrading in mariadb 10.1 (debian stretch) for now. We are experiencing two major issues with the production trafic: * We saw a huge increase in on disk tmp table space used (serveurs with 4Gb of free space in / (including /tmp) had to be added an additionnal 20Gb /tmp volume and even that is no enough everytime * If the replication process has to write a tmp file to execute the query, and log slave updates is active then in the even of the /tmp volume being full, the update of the binlog will also fail erroneouslly with a "No space" error and will stop every following binlog write. 2019-02-20 15:24:12 140618945124096 [ERROR] Slave SQL: Could not execute Write_rows_v1 event on table xxx.yyyy; Error writing file '/tmp/MLxClNzW' (Errcode: 28 "No space left on device"), Error_code: 3; Error writing file '/var/lib/mysql/mysql-bin' (errno: 28 "No space left on device"), Error_code: 1026; Writing one row to the row-based binary log failed, Error_code: 1534; handler error HA_ERR_RBR_LOGGING_FAILED; the event's master log mysql-bin.006843, end_log_pos 42848762, Gtid 0-70-467485, Internal MariaDB error code: 3 2019-02-20 15:24:12 140618945124096 [Warning] Slave: Error writing file '/tmp/MLxClNzW' (Errcode: 28 "No space left on device") Error_code: 3 2019-02-20 15:24:12 140618945124096 [Warning] Slave: Error writing file '/var/lib/mysql/mysql-bin' (errno: 28 "No space left on device") Error_code: 1026 2019-02-20 15:24:12 140618945124096 [Warning] Slave: Writing one row to the row-based binary log failed Error_code: 15342019-02-20 15:24:12 140618945124096 [ERROR] Error running query, slave SQL thread aborted. Fix the problem, and restart the slave SQL thread with "SLAVE START". We stopped at log 'mysql-bin.006843' position 42814887 Does someone know if they have been improvement in 10.2/10.3 on theses issues ?