You can use lower maxLo value, or another identity strategy.


Tuna Toksöz
Eternal sunshine of the open source mind.

http://devlicio.us/blogs/tuna_toksoz
http://tunatoksoz.com
http://twitter.com/tehlike




On Thu, Apr 2, 2009 at 4:52 PM, John Morales <[email protected]> wrote:

> I'm noticing a scalability issue with hilo and my web application. Every
> time the asp.net application restarts the app domain, the hilo generator
> uses a new set of hi values, not exhausting the previous set. This is
> causing fragmentation in the ids since the algorithm is more or less:
>
> hi * (maxLo + 1)  + hi  + lo
>
> Using the default maxlo of Int16.MaxValue and assuming a simplified
> application with just one table, I get the following: (Application restarts
> are simulated, but in ASP.NET the default is 20 minutes of inactivity,
> IIRC)
>
> Table 1
> ======
> 32768
> 32769
> 32770
> <Application Restart>
> 65536
> 65537
> 65538
> <Application Restart>
> 98304
> 98305
>
>
> I understand why this is happening and I don't need support for multiple
> concurrent session factories. I read in a previous thread, talk about
> keeping the current max hi for each table, that might help but ideally the
> generator would restart the hilo assignment where it left off. i.e.
>
> per each table...
> get old hi value
> get last lo value in db.
> check
> if lo < maxLo
>   current hi
> else get new hi.
>
>
> Have you guys faced this before, is it not an issue to burn through and
> fragment these ids?
>
> I rather not set the application pool not to restart, but I guess I could,
> MS says it's good practice to have application restart triggers on memory
> and time limits for asp.net applications.
>
>
>
> --
> This signature is intentionally left blank
>
> >
>

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups 
"nhusers" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to 
[email protected]
For more options, visit this group at 
http://groups.google.com/group/nhusers?hl=en
-~----------~----~----~----~------~----~------~--~---

Reply via email to