Interpreting jstat results

Question

I am new to jstat tool. Therefore I did a sample as below.

./jstat -gcutil -t 4001 5000
Timestamp         S0     S1     E      O      P     YGC     YGCT    FGC           


        

Answer 1

gcutil gives stats in terms of percentage utilization

-gcutil Option
Summary of Garbage Collection Statistics 
Column  Description
S0      Survivor space 0 utilization as a percentage of the space's current capacity.
S1      Survivor space 1 utilization as a percentage of the space's current capacity.
E       Eden space utilization as a percentage of the space's current capacity.
O       Old space utilization as a percentage of the space's current capacity.
P       Permanent space utilization as a percentage of the space's current capacity.
YGC     Number of young generation GC events.
YGCT    Young generation garbage collection time.
FGC     Number of full GC events.
FGCT    Full garbage collection time.
GCT     Total garbage collection time.

gc gives statistics in terms of alloted space and utilized space.

-gc Option
Garbage-collected heap statistics 
Column  Description
S0C     Current survivor space 0 capacity (KB).
S1C     Current survivor space 1 capacity (KB).
S0U     Survivor space 0 utilization (KB).
S1U     Survivor space 1 utilization (KB).
EC      Current eden space capacity (KB).
EU      Eden space utilization (KB).
OC      Current old space capacity (KB).
OU      Old space utilization (KB).
PC      Current permanent space capacity (KB).
PU      Permanent space utilization (KB).
YGC     Number of young generation GC Events.
YGCT    Young generation garbage collection time.
FGC     Number of full GC events.
FGCT    Full garbage collection time.
GCT     Total garbage collection time.

Source : Docs