hi tomaskir,
your guess was correct. The memory was unset.
After a search on the web, i made the change on CATALINA_OPTS="-Xms2048M -Xmx2048M".
this change should be in setenv.sh file (create it if doesn't exist) as [export CATALINA_OPTS="-Xms2048M -Xmx2048M"] in the same directory as catalina.sh wich will load it at the start. After a tomcat restart i was able to open MIB Explorer on Web interface.
thanks again and have a nice day 
sorry but i got http 404 not found, it seems that ubuntu repositroy does not install manager app auto so i have to resolve this issues and i will return to the forum tomorow
thanks for you help.
i have tried with "-Djava.awt.headless=true -Xms2048M -Xmx2048M" and with your suggestion but i cannot open the MIB Explorer on Web UI [chrome and FireFox browser].
it shows processing for some times and we got nothing however in the windows console app it work without any problem.
it's a fresh install did i forget something to intall ?
please help
thanks for your reply,
okay i understood the idea ! My tomcat version is 8 and his default JAVA_OPTS is "-Djava.awt.headless=true -Xms128M" but i have some questions.
what's the difference between Xms and Xmx options ?
how to optimize such parameters, known that my os is ubuntu server 14 with 8 Gb RAM ?
finally should i use "-Djava.awt.headless=true -Xms1024M -Xmx1024M"
thanks again.
Hi Victor,
Can you give us more details about -Xms and -Xmx options and how/where can we change it ?
