RDS MySQL replication issues

Question

Hi folks,
We have a MySQL replica instance running out of sync for a few days with the below errors. Not sure the issue is due to internal RDS db replication settings. Is there any solution to this issue? Thank you, in advance for your input.

Errors: 
[ERROR] [MY-010584] [Repl] Slave SQL for channel ‘’: Worker 1 failed executing transaction ‘ANONYMOUS’ at master log mysql-bin-changelog.052832, end_log_pos 1176205; Error ’Illegal mix of collations (utf8_general_ci,IMPLICIT) and (utf8mb4_general_ci,COERCIBLE) for operation ‘concat’' on query. Default database: ‘’. Query: ‘UPDATE `tenant_marbellaclub`.`billing_saleline` SET `description` = CONCAT(`description`, ’ No :hot_pepper: picante’) WHERE `id` IN (90756)’, Error_code: MY-001267

ktei · Answer

AWS Support can help you resolve such specific issue that requires investigation into your account. Please submit a support case from within your AWS account. Thanks.

Andrew · Answer

If you haven't resolved this problem yet, it appears your `@@collation_connection` is at odds with the collation on the `description` column, which is likely the result of your connection and column having different character sets.

You are trying to concat the `description` value with the literal ’No :hot_pepper: picante’. MySQL interprets the `description` column as character set **utf8**, collation **utf8_general_ci**. Your string literal has a character set of **utf8mb4**, collation **utf8mb4_general_ci**. MySQL's use of "utf8" allows up to three character bytes, while the actual full characterset "utf8mb4" allows up to four, matching Unicode standard.

You probably want to switch over any **utf8** columns to **utf8mb4**. This will also fix the collation issue, as utf8mb4_general_ci is the default collation for utf8mb4.

RDS MySQL replication issues

Relevant content