any rules of thumb to follow for restricting heap to eden (and not jumping the fence to permgen)?
thx Martin ______________________________________________ Disclaimer and confidentiality note Everything in this e-mail and any attachments relates to the official business of Sender. This transmission is of a confidential nature and Sender does not endorse distribution to any party other than intended recipient. Sender does not necessarily endorse content contained within this transmission. > Date: Tue, 10 Mar 2009 15:54:11 +0100 > Subject: Re: Effect of Heap Size on Performance? > From: rosenberg.l...@googlemail.com > To: users@tomcat.apache.org > > On Tue, Mar 10, 2009 at 3:41 PM, Christopher Schultz > <ch...@christopherschultz.net> wrote: > > -----BEGIN PGP SIGNED MESSAGE----- > > Hash: SHA1 > > > > Taylan, > > > > On 3/5/2009 5:11 AM, Taylan Develioglu wrote: > >> I always hold this as a ground rule: > >> > >> Increase heapsize as much as possible as long as: > > > > My rule has always been to run with the smallest heap you can get away > > with. We ran our main production app in 64MB of heap (the default for > > our platform) for 4 years before we got our first OOME. Now we run it > > with a 192MB heap. > > > > A smaller heap means that you'll catch even small memory leaks faster. > > At least, that's my position. > > > > Surprisingly, Chuck hasn't responded (he usually has something to say > > about GC/heap myths), but I suspect he'd say something like "heap size > > itself has little effect on the GC's performance... it's really the > > number of objects that affect the performance. > > > allow me to jump in in place :-) > > actually, with the default garbage collector, the amount of the > objects in the young generation has no effect on GCs performance, the > size of the young generation does. > Generally, more free memory, less GC, better performance. > > The number of short living objects (and usually 99.9% of your objects > are short-lived, or should be short lived), is irrelevant, since only > explicitelly accessible objects survive the young space. > > regards > Leon > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > For additional commands, e-mail: users-h...@tomcat.apache.org > _________________________________________________________________ Windows Live™ Groups: Create an online spot for your favorite groups to meet. http://windowslive.com/online/groups?ocid=TXT_TAGLM_WL_groups_032009
