Failed to connect to your instanceError establishing SSH

I am using AWS Ec2 hosting (1GB 1CPU) .my site is reached small trafic still.I don’t know why sometime my site loading fail.When try to connect instance “ Failed to connect to your instanceError establishing SSH connection to your instance. Try again later.”after re-start my instance problem is fix. I need to fix that.Need your help

Without essential details about your setup, e.g. OS, installation method etc., my guess is that you have insufficient resources to run Ghost on EC2.