-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Patrick,
On 1/30/13 4:44 PM, Patrick Flaherty wrote: > We are testing our complete app with 64 bit JVM and 64 bit Tomcat > and so far we have seen no issues. My question is how prevalent is > the deployment of 64 bit enterprise apps. (just to show my > naiveté). We use some open source tools and look to use more in the > future. Is there things I should be worried about in moving to 64 > bit in terms of open source tools? We have been using 64-bit in development and will be deploying to 64-bit in production this quarter: we have not seen any problems at all when switching architectures. One thing you have to realize is that all your pointers will be twice as big. Java uses a lot of pointers, so your nominal memory footprint will /increase/ merely by switching to a 64-bit JVM. What we've decided to do (at least temporarily) is to use "compressed OOPs"[1] which basically means that Java references will not take 64-bits but they will take 32-bits instead. This reduces the memory required by a 64-bit JVM but still gives you access to more than 4GiB (more like 2GiB) or heap space. It should also give you slightly better performance because shipping-around 32-bit values is quicker than shipping-around 64-bit values (at least in bulk it is). We don't need huge heaps. We don't even need to max-out a 32-bit JVM's heap. But, we suspect that 64-bit JVMs will be where most of the effort goes into optimization in the future so we're moving to 64-bit sooner rather than later. I hope it goes well for you. - -chris [1] https://wikis.oracle.com/display/HotSpotInternals/CompressedOops -----BEGIN PGP SIGNATURE----- Version: GnuPG/MacGPG2 v2.0.17 (Darwin) Comment: GPGTools - http://gpgtools.org Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEAREIAAYFAlEK8nkACgkQ9CaO5/Lv0PDAdgCbByhrghkBjjiN/pAfSxiWp1IC m6UAnApqOxQnvgDDucyeauBzNR41EeIe =7xKt -----END PGP SIGNATURE----- --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
