Another reader asks through email: There are times I have new connections but they do not show on my home page along with the history. I find that strange…. maybe there is a reason?
I’m not privy to details on how the LinkedIn environment works, but I can guess…
One database works well for a small group
Your checkbook is an example of a small database – you record the activity in and out, and things work well. But what happens when you’ve got to share your checkbook with a significant other?
Well, since there is one checkbook, it might be the the person holding the checkbook has control, but some times you might take some checks out – that can get messy…
It’s a made up example, but I’m sure you can see the implications that splitting up data and resources can cause issues. With 20 million user accounts, LinkedIn clearly is not a “small” database.
Multiple web servers, multiple instances of the database
So it seems likely that in order to respond to all of the web viewers, LinkedIn needs multiple systems running in parallel – each with a view to one one or more copies of the database.
Keeping them all “up to date” becomes an issue.
Perhaps you accepted a connection through Server A, and it updated instance 99 of the database.
Over time, that change will be reflected in all of the other servers and databases, but let’s say that just afterwards, you view your profile through Server Z and instance 42 of the database – the change might not have propagated to that system yet.
Some times things do go astray…
And of course, there is the potential that just like in my checkbook example above, an error gets made – and things don’t quite add up. After a while somebody generally notices that things are off and corrects it, but you’ll see a “weird thing” until that happens. Computers are, after all, programmed by mere humans;-)
So the next time you think something is “off”, just let it go, either ignore it, or come back a bit later. It’s not worth your time to fret about it – if the problem doesn’t go away on its own after 24 hours, then you might have to bring it to the attention. of support.
Hope that sheds some light on it for you!-)
steve