This is the sort of thing we call a scalability killer. Loading
everything into memory on one machine and then adding locks presumably
for writing to this memory means you are limiting any sort of horizontal
scalability and you are slowing down the one machine you do have with
lock contention.
Thanks your insightful comments. Clearly scalability is a concern for large
scale applications. One has to be discreet with it if such a facility is
available. For the dictionary example, I feel it definitely can use such a
facility and DB approach is much slower; and scalability/load balancing
In the example I gave, I mean the whole thing is loaded once, then every
session can use it. Basically it is like a cache, only it is available cross
sessions.
Clearly one can use DB to store data to do that, however, (1)there are
things that are not suitable to store in a DB; (2)DB is
http://eaccelerator.net/HomeUk Will keep scripts cached in memory etc.
Maybe this is along the lines of what you are looking for.
Aiguo Fei wrote:
Thanks your insightful comments. Clearly scalability is a concern for large
scale applications. One has to be discreet with it if such a facility
Aiguo Fei wrote:
Thanks your insightful comments. Clearly scalability is a concern for large
scale applications. One has to be discreet with it if such a facility is
available. For the dictionary example, I feel it definitely can use such a
facility and DB approach is much slower; and
Rasmus Lerdorf wrote:
Not much documentation is needed:
if(!$dict = apc_fetch('dict')) {
$dict = function_that_returns_a_dictionary_array_or_object();
apc_store('dict',$dict);
}
That's all. [snip]
-Rasmus
Wow, I should have tried harder to make it work.. thnx !
Evert
--
PHP
In ASP.Net there is the concept of application which is a virtual
directory on a Web server. An application can have application-wide
shared data/objects, which can be accessed by any script of that
application (i.e., scripts under the virtual directory). I have gone
through several PHP books,
Aiguo,
To achieve good performance, I want to load the
whole dictionary into memory when the application starts (e.g.,
when
the web server starts...
I'm not sure how ASP works, but in PHP you can't load something into
memory when the web server starts and keep it there. PHP 'compiles'
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