Java Jvm-jstat Viewing the GC status of the JVM [go]

The JPS (Java Virtual machine process Status Tool) is a command that JDK 1.5 provides to show all current Java process PID, and is simple and practical, ideal for linux/ Simple view of the current Java process on the UNIX platform.

JPS stored in the JAVA_HOME/BIN/JPS, when used for convenience please add java_home/bin/to path.

Jstat
1. JSTAT-GC PID
You can display GC information, the number of times the GC is viewed, and the time.
The last five items were the number of young GC, the time of young GC, the number of full GC, the time of full GC, and the total time of GC.
2.jstat-gccapacity PID
can display the use and occupancy of three generation (Young,old,perm) objects in VM memory,
For example: PGCMN shows the minimum perm memory usage, PGCMX shows the maximum memory usage of perm,
The PGC is the current newly generated perm memory footprint, and the PC is but the pre-perm memory footprint.
The other can be based on this analogy, OC is the old inside the pure consumption.
3.jstat-gcutil PID
Statistical GC information Statistics.
4.jstat-gcnew PID
Information about the young generation object.
5.jstat-gcnewcapacity PID
The information of the young generation object and its consumption.
6.jstat-gcold PID
The information for the old generation object.
7.stat-gcoldcapacity PID
The information and consumption of the old generation object.
8.jstat-gcpermcapacity PID
The information of the Perm object and its consumption.
9.jstat-class PID
Displays information such as the number of loaded classes, and the amount of space occupied.
10.jstat-compiler PID
Displays information such as the number of real-time VMS compiled.
11.stat-printcompilation PID
Information about the current VM execution.
Some terms are explained in Chinese:
S0C: Capacity of the first Survivor (Survivor area) in the Young Generation (bytes)
S1C: Capacity of the second survivor (Survivor area) in the younger generation (bytes)
S0U: The first survivor (Survivor area) of the young generation has currently used space (bytes)
S1U: The second survivor (Survivor area) of the young generation has currently used space (bytes)
EC: The Capacity of Eden (Eden) in the Young Generation (bytes)
EU: Eden (Eden) in the young generation has currently used space (bytes)
Capacity of the Oc:old generation (bytes)
Ou:old currently used space (bytes)
Pc:perm (persistent generation) capacity (bytes)
Pu:perm (persistent generation) currently used space (bytes)
YGC: Number of GC times in young generations from application startup to sampling
YGCT: The time taken by the GC in the young generation from application startup to sampling (s)
FGC: Old (full GC) GC count from application boot to sampling
FGCT: Time taken from an old (full GC) GC when the application boots to sampling (s)
GCT: GC Total time from Application boot to sample (s)
NGCMN: initial (minimum) size in Young generation (bytes)
NGCMX: Max capacity of young generation (bytes)
NGC: Current capacity in young generation (bytes)
The size (in bytes) of the initialization (minimum) in ogcmn:old generation
Maximum capacity of the Ogcmx:old generation (bytes)
The current newly generated capacity of the Ogc:old generation (bytes)
The size (in bytes) of the initialization (minimum) in pgcmn:perm generation
Maximum capacity of the Pgcmx:perm generation (bytes)
The current newly generated capacity of the Pgc:perm generation (bytes)
S0: The first survivor (Survivor area) of the young generation has been used as a percentage of current capacity
S1: The second survivor (Survivor area) in the younger generation has been used as a percentage of current capacity
E: Eden (Eden) in the young generation has been used as a percentage of current capacity
Percentage of current capacity used by O:old generation
Percentage of current capacity used by P:perm generation
S0CMX: Maximum Capacity (bytes) of the first Survivor (Survivor area) in the young generation
S1CMX: Maximum capacity of the second survivor (Survivor area) in the younger generation (bytes)
ECMX: Maximum capacity of Eden (Eden) in the Young Generation (bytes)
DSS: Capacity (bytes) currently required for Survivor (surviving area) (Eden area Full)
TT: Limited number of holds
MTT: Maximum number of hold limit

Reference: Jstat Viewing the GC status of the JVM [go]

Java Jvm-jstat Viewing the GC status of the JVM [go]