Low on RAM: Should i get two $20 dollars droplets (to combine 4 cores and 4Gb RAM ) or one $40 dollar droplet (2 cores and 4GB RAM)?

December 27, 2017 1.2k views
Server Optimization Ubuntu 16.04

Hello Digital Fellas.

I am getting pretty low on ram (338Mb Available) so i know i will have to upgrade very soon to a bigger droplet. But someone pointed to me that i could also get two $20 dollars droplets instead of one, to separate MYSQL from, Nginx Node, and Apache i guess and have 4 cores instead of 2. Cause Digital Ocean $40 dollars droplet comes with 2 cores and not the 4 than i can get if i pay for two $20 dollars droplets.

This is my setup and how i my current droplet:

I currently have a $20 dollar ubuntu 16.04 droplet with 68 running websites. I know they are a lot but since the websites do not get too many concurrent connections the ubuntu server has been working fine for more than a year now.

I am using Nginx and Mysql for the websites. All the websites have https enabled. (thanks to lets encrypt). and Im using php-fpm for a few websites in need of php. I also have apache configured as the backend for ONE website (you can configure Nginx as a reverse-proxy for Apache), but i am planning to maybe move that particular website to its own droplet, cause its the only one in need of Apache. Basically i have Apache in my server for just one website. And Nginx for the rest.

Also i have discovered in the last few months about the Ghost Blog application which i think its pretty cool. But i had to install node on my server. Since then i have created about six Ghost blogs on my droplet. I have noticed that this ghost blog are pretty RAM consuming. Also every blog has to have its own Mysql database.

Since i have HTOP installed i can run this command: ps -A --sort -rss -o comm,pmem | head -n 11 and get this result:

mysqld          21.8
node             4.7
node             4.4
node             4.3
node             4.3
node             4.2
node             4.2
php-fpm7.0       4.2
php-fpm7.0       4.0
node             4.0

Also the Digital Ocean Top Processes Graphic gime more or less similar numbers for RAM consumption:

<^>node 34.44 %
mysqld 21.84 %
ghost run 14.39 %
php-fpm7.0 13.66 %
nginx 3.57 %

apache2 2.42 %

systemd-journal 1.43 % <^>

The CPU usage is very Low so it does not worry me. What worries me is that i only have around 338 Mb of RAM left. I am worried in future concurrent connections that might collapse the droplet.

So what do you recommend. Should i go for one $40 dollar droplet or two $20 dollar droplets and separate things? Also how should i separate them? Should i have MYSQL on one droplet and all the other stuff (Nginx, Node and PHP - FPM ) on the other? What are the pros and cons? I am new in this. Thanks in advanced.

1 Answer

I think you are on the right track looking into your existing CPU/RAM usage and coming up with a logical way to split up usage across 2 droplets.... but I'm not sure at all if its just better to let the OS do thread ballancing. I have a simmilar situation, minus getting extra CPU cores with 2 droplets:

I'm curious about a simmilar dillema. Should I get 2 $10 droplets or 1 $20 droplet?

I plan on doing web application hosting with nginx, postgresql, python/Django, and some data crunching with Python in the background on a daily scheduled interval. While maybe also hosting a small Mumble voicechat server, OpenVPN, and a torrent client.

Would it be better to go with 2 droplets and split these services up, or just go with a single droplet and hope the OS kernel ballances the CPU threads good enough on it's own.

I'm going to start off with what you have done and start with a single $20 droplet, set everything up, and look into the Monitoring data, as to what proccesses are the biggest culprits. If there are any proccesses that are regularly high CPU or RAM, i would imaging it might be somewhat benefitical to have 2 droplets, and split up certain things.... but i'm just guessing here.

obviously your situation is different becuase you are getting more cores with 2 droplets, which would seem to make that option superior to me. I'm still curious about a more 1:1 comparison of benefits:resources to my scenario though.

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