I have a shared hosting with Godaddy. My site was going slow when I was connecting to the database with some processing. Hence, I recently upgraded to the ultimate plan with 2 shared CPUs and 1GB RAM as suggested by their hosting support. It was working perfectly fine for a month but has gone again very slow after a month with same level of processing. Can you suggest what to do in this case? I am not sure if going for a business plan will help or not as there is no option to test it before taking up. Moreover it was working perfectly fine for a month, hence not sure what has gone wrong now.
DNS - That's your browser looking for your website. It's usually cached though and becomes 0 after the first connect. Can't do much about it.
Connect - Better server network will help... Dedicated/VPS is better because those have less traffic going through their network. Imagine your home network/wifi, more users = slower.
First byte - That's how long it took your server to process the request (server side, database query and all). Use better performing queries, WP sites are terrible at this. Use JOIN when possible, prepared statements are not only safer but also have less overhead. USE CACHING, WP total cache is legit... Some queries are queried over and over again, if you can cache the results of that query and server it instead, it will make your server faster. Localhost DB is also a lot faster.
Last byte - That's how long it took your browser to download all your documents (html, css, js, fonts, images). Use CDNs to make files available to your visitors faster, compress your files (gzip is now widely supported), compile CSS and JS to make them lighter. Combine files like CSS and JS when possible because each request adds an overhead. Some browsers, especially mobile browsers, are only able to download 4 files simultaneously (most WP sites does 30 to 90 + http requests, should be less than 10)
Bonus: Render, paint - That's how long it took your browser to process everything it downloaded like CSS and JS. Well, don't do a lot of client side processing. This is especially terrible for mobile devices because they have less processing power.
The most beneficial and easiest to implement is caching. It's hard to tell what's going wrong with your hosting without a baseline data. Run the test above at least a couple of times a week to see what's changing.
~Jan Mykhail Hasselbring Web Administrator @ fullstackwebsolution.com