Ok, WhatsApp does scale exceptionally well with very little resources, but those number aren't really accurate.
It is not billion messages / second, that would imply majority of the WhatsApp user were awake and send a message in the same second. But right now it may be more than a million per second. During its FreeBSD era ( They switched to Linux when Facebook bought them ) it was doing ~400K messages / sec during peak. And it is not 1000, during it FreeBSD era is was handling it with less than 150 server for Chat. And that was with a very non powerful 10-Core Ivy Bridge Servers. I often wonder if they could handle the same in 20 Servers when we have 128 Core Per Server today.
Ok, WhatsApp does scale exceptionally well with very little resources, but those number aren't really accurate.
It is not billion messages / second, that would imply majority of the WhatsApp user were awake and send a message in the same second. But right now it may be more than a million per second. During its FreeBSD era ( They switched to Linux when Facebook bought them ) it was doing ~400K messages / sec during peak. And it is not 1000, during it FreeBSD era is was handling it with less than 150 server for Chat. And that was with a very non powerful 10-Core Ivy Bridge Servers. I often wonder if they could handle the same in 20 Servers when we have 128 Core Per Server today.