I haven’t visited my blog for a while, so was very surprised to see “Error Establishing a Database Connection” page. At first I thought someone had hacked my box 🙂 Instead MySQL server was down. I checked server logs and found fatal errors from mysql:
InnoDB: Fatal error: cannot allocate memory for the buffer pool
I googled that issue immediately and according to StackExchange my database couldn’t allocate more system memory and process died. Hm, 1G of RAM is not enough for a tiny blog???
Anyway, I have moved WordPress database to Amazon RDS. I went with t2.micro so it shouldn’t cost much. For the safety reason my instance does not have public IP and allows only connections from WordPress host.