Why do software installation or updates always go very fast up to 90% complete, then the last 5-10% takes so much longer?
In: Technology
When you write to a file typically the operating system will keep the data in memory, so not actually written yet to disk – until it really needs to, which usually happens with an explicit fsync() call at the end of the install that guarantees that the data has actually been written to disk.
Operating systems do this because it’s more efficient to batch the writes and write them as chunks instead of actually going all the way to writing to disk on every write
Let’s say I’m a programmer and I have to make a progress bar for shopping for groceries.
Here are the steps:
1. Go to garage
2. Drive to store
3. Get out of car
4. Walk into store
5. Get shopping cart
6. Procure items
7. Pay for items at checkout
8. Return to car
9. Unload groceries
10. Drive home
Since there are 10 steps, I code my progress bar to increase by 10% after each step. I could have been smarter about it, but there’s a lot more on my sprint backlog so this is good enough for now.
Result: progress bar jumps to 10%, waits there the entire time I drive to the store, quickly reaches 50% for a while while I shop, then 60% for a few minutes while I’m in line, then quickly reaches 90% and stays there until I finally get home.
Your progress bar probably works a lot like this. Now, I could program it so the longest steps get more % but a lot of the time that’s hard to predict.
The real key here is that a programmer actually had to decide how to code it up. Some engineer somewhere wrote the code that includes a formula (so to speak) on how to compute the current % and that formula may not be accurate.
Latest Answers