Re: Best Notification Framework
Re: Best Notification Framework
- Subject: Re: Best Notification Framework
- From: Sam Hart <email@hidden>
- Date: Wed, 4 Feb 2004 15:37:08 +0000
Denis wrote:
You know probably more than I do!...
long and bitter experience
I suggested this in the case that the data is read-only in the
application.
interesting
That would increase the traffic between the application and the
database
well, yes, you would be fetching data that potentially hasn't changed
plus if you invalidate a lot of objects you will create a bottle-neck
and if you invalidate all objects you will get "Thrashing" where no
useful
work is done but resources are consumed ( memory for example ).
but the database needs to be hit anyway to get fresh data.
true but you only want to fetch the data that has changed, when it
changes
less overhead, more accurate data.
Can you detail why it is such a bad idea?
Concurrency and cache-coherency on a multi-user, multi-instance system.
Imagine you alter something in one instance but then due to load
balancing
you end up in a different instance before the update interval.
When you only have a couple of users it's no big deal,
when you have 100s running around on the system you soon know about it.
That is why we are all into Change Notification,
I lived without it for a while, never again !
S a m
ps. You're not based down in Uxbridge are you ?
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