topic Re: How can I increase java heap space in SAS Programming

How can I increase java heap space

ninemileshigh — Mon, 10 Jul 2023 10:06:48 GMT

I am using SAS 9.4 M3 in Windows 10. It's a new installation after a Windows rebuild.

I am trying to draw a graph from a large dataset (4.5 gb) using Sgplot. The code runs really slowly and eventually I get the following error code:

ERROR: Java virtual machine exception. java.lang.OutOfMemoryError: Java heap space.

I have tried to change the java heap space allocated to SAS using a couple of different methods:

1. by altering jre options in the the config file. I have changed the config file so that

-Xms1024m
-Xmx1024m

2. I have also tried to alter the default java heap space in Windows

https://stackoverflow.com/questions/17369522/set-default-heap-size-in-windows

3. I also tried opening SAS from a command prompt with the following jre options specified

"c:\program files\SASHome\SASFoundation\9.4\sas.exe" -ls 80 -ps 60
-config "C:\Program Files\SASHome\SASFoundation\9.4\nls\en\sasv9.cfg"
-jreoptions '(-Xmx1024m -Xms2048m)'

None of these has altered the heap space, which I check by running the following:

proc options option=jreoptions; run;

The log returns

JREOPTIONS=(/* other Java suboptions */ -Xmx128m -Xms128m)

What am I doing wrong?

In addition to failing to draw a graph of the whole dataset, SAS runs extremely slowly when asked to draw many graphs on subests of the data. I haven't had these problems on previous installations of SAS. The time taken to create 2128 graphs is:

NOTE: Writing HTML Body file: sashtml.htm
NOTE: PROCEDURE SGPLOT used (Total process time):
real time 4:35:13.73
cpu time 1:55.37

Which equates to approximately 3.25 secnods of CPU time per graph- which seems really long.

Re: How can I increase java heap space

JosvanderVelden — Mon, 10 Jul 2023 13:20:03 GMT

Do you want to set the jreoptions just for a single session or permanently?
If for a single session you can start sas via the command prompt with something like "sas -jreoptions '(-Xmx256m -Xms256m)'" Note: you can use higher values ex 512m or even 1024m but should only do that if needed and if you have lots of RAM. The suggested value is 1/4 of the memsize option set for the sas session. If you want to create a customized configuration file please read: https://documentation.sas.com/doc/en/pgmsascdc/9.4_3.5/hostwin/p0bmj7wjme32ayn1h4wim7trkhp6.htm#n19ns7rwcgjykbn1ffzdy6wuy795

Re: How can I increase java heap space

ninemileshigh — Wed, 12 Jul 2023 16:05:47 GMT

thank you for your reply. I owuld probably want to alter this permanently since I often use very large datasets.

I have 8 gb of RAM, so would it make sense to increase the allocation as much as I can to speed up sgplot?

The problem is, none of the methods of increasing heap space are working: I have tried a command prompt with increased jre options, AND I have also altered the config file, and yet SAS still only has 128 mb allocated.

Re: How can I increase java heap space

ballardw — Wed, 12 Jul 2023 17:35:13 GMT

One might also consider the actual SGPLOT code involved. How much of that 4.5 Gb dataset is actually used by Sgplot? What type of plot/plots are involved? Perhaps a different plot approach would reduce memory need.

Re: How can I increase java heap space

Reeza — Wed, 12 Jul 2023 17:44:49 GMT

Trying to graph 4.5GB of data seems like it would tax a system for sure.

Can you pre-summarize or simplify the data before using SGPLOT?

Re: How can I increase java heap space

JosvanderVelden — Fri, 14 Jul 2023 11:13:22 GMT

I was able to change the sas9.cfg to change jreoptions memsize and sortsize.
I verified the changes and the changes were correctly applied. In your case I would advice against changing the defaults since you have only 8gb RAM. You will always have make sure the OS has enough RAM to run. So if you would like to change then memsize could be set to 4gb and in that case jreoptions could be set to -Xmx256m -Xms1024m. I doubt that would change the outcome regarding the "Java virtual machine exception". If you want to try please let me know.