What values do use for MaxTenuringThreshold?

Tony Printezis tony.printezis at sun.com
Fri May 30 20:04:43 UTC 2008


Y Srinivas Ramakrishna wrote:
> Please ignore this:-
>> There is probably a small class of very specific applications (such as
>> seen sometimes in telecoms -- and occasionally in certain ecommerce
>> settings as Peter will attest -- where there is no state associated with
>> very short-lived transactions for example) which are essentially
>> non-generational in the time-scale of the scavenges. At a finer time-scale
>> I am sure some generational behaviour would emerge even in these
>> applications.
> What I described above certainly conforms to the accepted definition of
> "generational behaviour" -- most objects die young -- in this case
> it turns out that the small fraction of objects that do not die very young die in middle
> age; they are not "long-lived" for some notion of "long".
> In fact this would be a highly generational application that never needs
> to use the older generation.
(playing Devil's advocate here a bit!) It is indeed a highly 
generational application. Most Java JVMs use a two-generation approach 
and, for better or worse, we seem to always try to fit the an 
application's patter into that. For many, it works. However, for some 
(like the above), it might not work out as well (due to the medium-lived 
objects generally surviving the young generation). But it doesn't mean 
the app is not generational; in fact, maybe a 3-generation system might 
fit such applications better.

> I guess i entangled generational configurations and generational behaviour
> and hence my confused ramblings for which my apologies ... :-)
> -- ramki

| Tony Printezis, Staff Engineer    | Sun Microsystems Inc.          |
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