The story happened with a webshop application running on Amazon EC2 microinstances. Actually on two instance. Amazon business model is basically simple, they ask money for only three things: Cpu time, IOPS and network traffic. Everybody (including me) thinks for the first time network traffic will be the bottleneck until they got the first bill (it can be even after one year considering the free tier). Actually in this category the IOPS is the most expensive.
On the cacti diagrams I saw strange datas. The created temp tables on disk and created temp files were much higher than created temp tables. The 67% of temporary tables were created on disk. This is very far from optimal.
Temporary objects in MySQL
II increased the max_heap_table_size and tmp_table_size from …[Read more]