12-03-2008 07:41 AM
due to increasing memory dempands of our Java application, we plan to increase its heap size from 4GB to 5GB (changing "-Xmx4096 -Xmx
4096 to -Xmx5120). What kernel parameters could restrict full utilisation of the increase? I am aware of:
I am not sure if:
could also have an impact or not. Please, what parameters should be checked for the increasing of java heap size? Thanks in advance for a feedback.
12-03-2008 07:48 AM
The data or heap space is going to be limited by 'maxdsiz' for 32-bit processes and by 'maxdsiz_64bit' for 64-bit processes. These should be the only parameters you need to factor into your increase.
12-03-2008 09:51 AM
#kctune -q maxdsiz_64bit
Tunable Value Expression Changes
maxdsiz_64bit 10737418240 10737418240 Immed
12-03-2008 10:52 AM
Technically you should look at the Total line, Free column of "swapinfo -atm"... The Java heap will need swap reservation to be created, so your total swap comes into play. Hence you may need to care about maxswapchunks (only on 11.0 or 11.11, obsolete on later releases), swchunk and swapmem_on (obsolete on 11.31) since those can affect configured swap space. Most likely there's still plenty of swap space, though... just check to be sure.