Full Storage of RDS for MySQL Instances

Symptom

There is not enough storage available for an RDS instance and the instance becomes read-only, so applications cannot write any data to the instance.

Causes

1. Increased workload data
2. Too much data being stored
3. Excessive binlogs generated by a high volume of transactions and write operations
4. Too many temporary files generated due to a large number of sorting queries executed by applications

Solution

1. As your workload data grows, the original storage space may be insufficient. If this happens, scale up storage space.

   If the storage capacity has reached the upper limit of your DB instance class, upgrade the instance class first.

2. If too much data is stored, delete unnecessary historical data.
   1. If the instance becomes read-only, unlock it from this state first. If it is not read-only, delete the data directly.
   2. To free up space, you can run OPTIMIZE on tables with a high fragmentation rate during off-peak hours.

      To clear an entire table, run DROP or TRUNCATE. To delete only part of table data, run DELETE. However, after performing DELETE, you need to run OPTIMIZE TABLE to reclaim the released storage space.

3. If binlog files are taking up too much space, you can delete local binlogs to free up your storage.
4. If temporary files generated by sorting queries occupy too much storage space, optimize your SQL statements.