recently I have added 2 managed servers to one of our servers. so totally the server has 4 managed servers. One of the managed server, which was previously using 0.6 GB is seen to use 1.8 GB now and it seems to increase as well.
WHat might be the cause of this situation? will increasing RAM solve this issue?
What you have shared is not sufficient to give a possible solution.. but please consider enabling GC logging (for which you can refer JVM documentations) and then review the GC logging (you can use any GC reviewing tools like HPJmeter, etc) and try to locate if there is an increasing memory pattern. If in case there is one, you should consider collecting a few heap dump at different situation and review them to understand whats in the heap..
0.6 GB of what Disk Space or RAM? Your Weblogic JVM managed server is fixed in heap size so there is no chance of increase. This will be evident when you declare memory arguments during managed server creation. For eg: 1 GB of Memory to managed server is always 1 GB of JVM process. Secondly if you see memory increase from your application within JVM it could be memory leak. Finally, check what else is consuming your RAM memory other than JVM by using "top" command if you are in unix.
Try using Jrockit Mission Control and do a "Flight Recording" to see your runtime parameters and analyze it.
We have RAM utilization issue but that will not affect weblogic because our free heap is enough to accomodate extra transactions.