Re: Memory Management

On Wed, Sep 8, 2010 at 12:32 PM, Obnoxio The Clown <obnoxio@serendipita.com>wrote: > Ian Michael Gumby wrote: > > > > need parallel processing? Maybe not. Do you need to go beyond 16GB most > > likely unless you have a really small system and support a small number > > of users. > > What is "a small number of users", though? If your application is > well-written (a big "if", I know!) then I reckon you could easily > support hundreds, even thousands of concurrent sessions. > > IBM is evidently touting a recent test with a partner who managed a > sustained insert rate of around 50,000 inserts per second using Time > Series (which is allegedly slightly less efficient than B-Tree) on a > Growth Edition configuration. > > I remember seeing an old green-screen app running 200+ heavy users on an > old, sub GHz, single CPU, single core Pentium box. I'm really not sure > that 16GB is a massive constraint on a *well-written* OLTP app. > > But if your app isn't well-written, well, nothing is going to compensate > for that, is it? > > -- > Cheers, > Obnoxio The Clown > > http://obotheclown.blogspot.com > I will now proceed to pleasure myself with this fish. > Again.... 2000+ concurrent sessions, 3 databases, several applications and (I really hope they won't read this....) most of them are badly written: $ onstat - IBM Informix Dynamic Server Version 11.50.FC5 -- On-Line (Prim) -- Up 51 days 11:01:46 -- 11106012 Kbytes $ onstat -u | tail -2 1915 active, 2944 total, 1953 maximum concurrent That's around 11GB... And it reached nearly 3000 since it was "born". It has probably allocaded more segment(s), but it's currently using around 70% of the Growth Edition limit... So, please... Don't use the "GB / core" metric where it doesn't make sense (if it ever does...) More cores allow more CPUVPs. You never need GBs per each CPUVP. Of course many cores, means greater workloads and that probably means more memory, but it's not a simple math question. Regards. -- Fernando Nunes Portugal http://informix-technology.blogspot.com My email works... but I don't check it frequently...