Monday, August 20, 2018

Scalability - Getting hang of Seconds

This post list some of the most important numbers which are important for engineers to do back of envelope calculations. This post, I have focussed on seconds. If you hear someone telling that his service gets 1 million hits a day; don't get bogged down with the numbers, it just means he gets 10 requests per second.


Seconds

# Seconds in a day = 86400  (=24*60*60)
                                = 0.85*10^5
                                = 10^5
                                = 0.1 million

# Seconds in a month = 2592000 (=30*86400)
                                     =  2.5*10^6
                                     = 2.5 millions

If an online site gets 10 million hits per day then it means on an average it gets 100 requests/sec.
If an online site gets 10 million hits per month then it means on an average it gets 4 requests/sec.

# Seconds in a year = 31104000 (=12*259200)
                                  = 31 millions
                                  = Pie * 10^7

   If we treat a year as 365.25 days then also, # seconds in a year would be 3,155,7600 which would approximate to 31 million. 

# Seconds in a century = 3,155,760,000 seconds (considering 1 year = 365.25 days)
                                       = 3.15 billions 
                                     
Nanocentury is 1 billionth of a century. So, a nanocentry = 3.15 seconds.
i.e. Pie seconds are there in a nano century. This is also known as Duff's Rule.