Sudden issues with 512MB Ubuntu 14.04 WordPress droplet

The droplet was created with WordPress on Ubuntu 14.04 image.

I’ve had a WordPress site (with probably zero traffic) running for a while now. Suddenly I noticed it reported a database connection error, fair enough. So I checked:

“service mysql status”

That returned stop/waiting, fair enough. Easy to get back running. It then crashed again eventually, and so forth.

I read up and noticed comments on creating a swap, which I then did exactly according to this guide.

“free -m” shows:

             total       used       free     shared    buffers     cached
Mem:           490        485          4         12          0         20
-/+ buffers/cache:        464         25
Swap:         4095        897       3198

The result of adding swap? My droplet is sometimes super slow while accessing it via SSH, i.e. typing into it lags. Never had this before, so I assume it is related. Also, the website doesn’t respond any longer. Ever. Sometimes the browser gets past connecting, but never past waiting.

What went wrong? Which logs should I check?

Surely a WordPress without almost no traffic shouldn’t have issues on even the smallest droplet. I’ve previously had a few sites running on the 512MB perfectly fine.