500 million is becoming a horrible negative number on replicas

Question

I need some assistance understanding what looks like a corrupted value in replicas.

Here's the scenario: 1 primary database, 8 read replicas. Database is MySQL, deployed with Amazon RDS. There is a single cell of data we are aware of that has the wrong value, only on read replicas. On the primary it's 500000000, on replicas it's -14592094872. Here's the column definition:

`amount` bigint NOT NULL

Here's some additional information:

• SELECT VERSION(); returns 8.0.40 on all of these.
• SHOW VARIABLES LIKE 'binlog_format'; shows MIXED on the primary, and ROW on replicas.
• show replica status doesn't seem to show any issues.
• show create table ... shows the column has the same type on both the primary and replicas.

I ran select hex(amount) ... to get these values, in case they're helpful:

• 1DCD6500 (correct primary value)
• FFFFFFFC9A3E4D68 (incorrect replica value)

Answer 1

Your column is the wrong type and your data value has overflowed. Increase the size of integer it is defined as.