I've been running a website for 4 months now and in that time, it has grown from a few hundred unique visits/day to about 30,000 unique visits/day. I have been on Linode the whole time and have steadily upgraded to a 4GB node. Unfortunately, my app is very MySQL heavy and even with caching, the server is frequently ceasing to respond in peak times. During these times, all 4 cores are maxed on the machine (though Linode 4GB only provides a 1/5 share of the CPU). The only way to get it running again is to restart MySQL.

I don't really know what to do. I have tried optimising the InnoDB settings and it seems to not be helping. Would moving to a Dedicated host be a good solution? I can get 4-5x the power of my node for a similar price - and with decent providers too.