SQL Server not scaling

I've been having bad 503 errors and SQL server errors. Seems like it might not be able to handle the current traffic load spikes?

I'm aware of capacity issues - it is not possible for me to simulate real traffic like this on my dev environment, so when capacity problems are reached it's usually the first time I see them (in the context of the current codebase and users).

Spent today trawling through and analysing the mysqld slow queries logs and found some rogue queries that were using up a lot of server resources. Have removed these and also enabled (yet another) cacheing layer for SQL queries. Truncated sessions table, purged entire cache, HTTPD restart and also a full rack restart.

Let me know if it feels better for you today BinaryShrub.