*-XX:+PrintGCDetails *will print more details at garbage collection. h3. Minor Garbage Collection: As per the description provided by Sun, the minor collection output created by parameters *-verbosegc -XX:+PrintGCDetails *looks like:
*+[GC [ secs]+*
+ +
Let’s see a more real example:
*83.304: *This is the start time of the collection since the VM started.
*GC* indicates that this is a minor garbage collector. If the executed collection is a global one, then we will see *FullGC* instead of GC.
*DefNew:* This is the *collector type *used for the minor collection. The most common values here are DefNew and ParNew. This depends again on the parameters we set for the JVM, for example *-XX:+UseParNewGC *(for the Parallel New garbage collector).
*890K: *This value refers to the size of the young generation which is allocated before GC takes place.
*64K: *This value is the young area allocated after GC (ideally, it should be smaller).
*960K:* This value is the maximum young area available (Eden + one of the survivor areas). *0.004494 secs: T*his is the pause time for the minor collection. *890K: *This is the occupancy of the entire heap before GC.
*217K: * This is the occupancy of the entire heap after GC. *5056K: *Maximum heap available (max heap – one of the survivor areas).
*0.004606 secs: *Pause time for the entire garbage collection. h3. Full Garbage Collection: As we have alredy mentioned, when a full garbage collection takes place, the tag *Full GC *appears in the GC output, as you can see in the following example:
*3074.315:* This is the start time of the collection since the VM started.
*1738752K: *This is the size of the tenured area allocated before the GC.
*1738751K: *This is the size of the tenured area allocated after GC (this should be a smaller value).
**1738752K: This is the maximum tenured area available (MaxHeap – Young).
*2007551K: *This is the heap allocated before GC.
*1773223K:* This is the heap allocated after GC. *2007552K: *This is the maximum available heap (MaxHeap – one of the survivor areas).
*246227K: * This is the perm area allocated before GC. *246227K:* This is the perm area allocated after GC.