not gonna lie this is driving me nuts my site has been running fine for months on Nginx in front of a Node app... now it falls over only during traffic spikes and all visitors get this:

502 Bad Gateway
nginx
restarting everything brings it back, until it doesn't. i'm not a full-time sysadmin, i set this up from a tutorial and it just worked. now i'm staring at log files i barely understand. which log should i look at first, and what am i looking for?? any ideas??
