HPjmeter 4.3 User's Guide

Table 9 Supported -Xverbosegc options for Java 1.5.0.04 (continued)

filename writes output to the specified file.

[n][h][d][u][t] n prevents appending the pid to the log filename.

h appends the hostname to the log file name.

u appends the username to the log file name.

d appends the date to the log file name.

t appends the time to the log file name.

At every selected garbage collection, the following 20 fields are printed. These values hold true

for Java 1.5.0.04. Other versions may differ. To see the complete list of available fields for the

Java version you are running, use

java ... -Xverbosegc:help

Table 10 Fields Captured in GC Log Data When Using -Xverbosegc print options

Type of garbage collection.

1 = scavenge (of new generation only)

2 = old generation GC or full GC

3 = complete background, concurrent mark and sweep (CMS) GC

4 = incomplete background, concurrent mark and sweep GC

5 = Evacuation Pause in G1

6 = Complete G1 Concurrent Mark Cycle

7 = Incomplete G1 Concurrent Mark Cycle

11 = Ongoing CMS GC

12 = Ongoing G1 Concurrent Mark Cycle

This value varies depending on the value of %1.%2

• When %1 is equal to 1, %2 indicates whether or not a parallel scavenge occurred. Possible values are:

0: non-parallel scavenge◦

◦ n(>0): parallel scavenge with n number of parallel GC threads

• When %1 is equal to 2, %2 indicates that an old generation GC or full GC has occurred. Reasons for the GC

are given as:

◦ 1: Allocation failure, followed by a failed scavenge, leading to a full GC

◦ 2: Call to System.gc made

◦ 3: Tenured generation is full

◦ 4: Permanent generation is full

◦ 5: Scavenge followed by a train collection

◦ 6: Concurrent-Mark-Sweep (CMS) generation is full

◦ 7: Old generation expanded on last scavenge

◦ 8: Old generation too full to scavenge

◦ 9: FullGCAlot

◦ 10: Allocation profiler triggered

◦ 11: JVMTI-forced garbage collection

◦ 12: Adaptive size policy

Obtaining Garbage Collection Data 95