Sunday, March 22, 2015

இவருக்கு பதில் இவர் JVM 8 has Only Metaspace instead of permgen

இவருக்கு பதில் இவர் JVM 8 has Only Metaspace instead of permgen


Permanent Generation has Space Restriction
Metaspace is Virtually UnLimited in Memory Space



The code will keep generating new classes and loading their definitions to Metaspace until the space is fully utilized and the “java.lang.OutOfMemoryError: Metaspace” is thrown.
When launched with -XX:MaxMetaspaceSize=64m then on Mac OS X the Java 1.8.0_05 will die at around 70,000 classes loaded.

Solution for java.lang.OutOfMemoryError in JVM 8
-XX:MaxMetaspaceSize=512m

Memory pool generation and space capacities.
NGCMN: Minimum new generation capacity (kB).
NGCMX: Maximum new generation capacity (kB).
NGC: Current new generation capacity (kB).
S0C: Current survivor space 0 capacity (kB).
S1C: Current survivor space 1 capacity (kB).
EC: Current eden space capacity (kB).
OGCMN: Minimum old generation capacity (kB).
OGCMX: Maximum old generation capacity (kB).
OGC: Current old generation capacity (kB).
OC: Current old space capacity (kB).
MCMN: Minimum metaspace capacity (kB).
MCMX: Maximum metaspace capacity (kB).
MC: Metaspace capacity (kB).
CCSMN: Compressed class space minimum capacity (kB).
CCSMX: Compressed class space maximum capacity (kB).
CCSC: Compressed class space capacity (kB).
YGC: Number of young generation GC events.
FGC: Number of full GC events.


MC: Metaspace capacity (kB).
MU: Metaspace utilization (kB).
CCSC: Compressed class space capacity (kB).
CCSU: Compressed class space used (kB).
OC: Current old space capacity (kB).
OU: Old space utilization (kB).
YGC: Number of young generation GC events.
FGC: Number of full GC events.
FGCT: Full garbage collection time.
GCT: Total garbage collection time.