Recently in our new environment, we got out of memory and perm gen errors while doing deployment on weblogic server. I have taken heap dump using below mentioned jmap command. command: jmap -dump:format=b,file=heap.bin 5004 Note: 5004 is weblogic server process id After that incresed the heap size from 1GB to 2GB and perm gen size from 512m to 640m. And then taken restart of weblogic instance and after that deployed application succesfully. After analying the heap dump using IBM memory analyzer tool, found the following classloader errors in analyzer console. ================================================================= 20 instances of "weblogic.utils.classloaders.ChangeAwareClassLoader", loaded by "sun.misc.Launcher$AppClassLoader @ 0xc0000f40" occupy 2,42,85,568 (27.16%) bytes. Biggest instances: •weblogic.utils.classloaders.ChangeAwareClassLoader @ 0xc14e0770 - 30,27,624 (3.39%) bytes. •weblogic.utils.classloaders.ChangeAwareClassLoader @ 0xc149e270 - 21,77,352 (2.44%) bytes. •weblogic.utils.classloaders.ChangeAwareClassLoader @ 0xc0dc9300 - 21,23,592 (2.38%) bytes. •weblogic.utils.classloaders.ChangeAwareClassLoader @ 0xc4b299d8 - 21,19,592 (2.37%) bytes. •weblogic.utils.classloaders.ChangeAwareClassLoader @ 0xc3d556c0 - 19,94,592 (2.23%) bytes. •weblogic.utils.classloaders.ChangeAwareClassLoader @ 0xc3d51248 - 19,17,592 (2.14%) bytes. •weblogic.utils.classloaders.ChangeAwareClassLoader @ 0xc1358b08 - 18,90,544 (2.11%) bytes. •weblogic.utils.classloaders.ChangeAwareClassLoader @ 0xc3d51738 - 18,42,968 (2.06%) bytes. •weblogic.utils.classloaders.ChangeAwareClassLoader @ 0xc1359358 - 18,30,656 (2.05%) bytes. •weblogic.utils.classloaders.ChangeAwareClassLoader @ 0xc13662c8 - 18,24,680 (2.04%) bytes. •weblogic.utils.classloaders.ChangeAwareClassLoader @ 0xc13f45b0 - 17,62,784 (1.97%) bytes. •weblogic.utils.classloaders.ChangeAwareClassLoader @ 0xc4ed4ef8 - 17,07,752 (1.91%) bytes. Keywords sun.misc.Launcher$AppClassLoader @ 0xc0000f40 weblogic.utils.classloaders.ChangeAwareClassLoader ============================================================== I think this issue is related to weblogic classloader issue. If the memory leaks are happening due to a Weblogic Class, it can be a known issue or an undiscovered BUG. In this case, we need to check with Oracle Support. If it’s an Application Class, you need to contact the developers. Out of Memory can also happen due to third party codes such as database drivers. Thanks Krishna