By default, Google Compute Engine VPS does not come with any swap space, If your program eat more memory, you can just add swap space instead of increasing RAM.

1. sudo fallocate -l 2G /swapfile Create file for swap.
2. sudo chmod 600 /swapfile Set the necessary permissions.
3. sudo mkswap /swapfile Make it a swap file.
4. sudo swapon /swapfile Turn on swapping on the file you created.
5. sudo swapon -s Check status of swap file.

To make this permanent add this to /etc/fstab

/swapfile none swap sw 0 0

Run sudo vi /etc/fstab to edit that file. Or use your preferred text editor.

If you need to resize the swap file

1. sudo swapoff /swapfile Turn off swapping.
2. sudo fallocate -l 4G /swapfile Change file size, replace 4G with the size you prefer.
3. sudo mkswap /swapfile Make it a swap file again.
4. sudo swapon /swapfile Turn on swapping again.

Source: Badly Wired