-XX:[+|-]HitachiVerboseGC (Option for extended verbosegc information output)
- Organization of this page
Format
- -XX:+HitachiVerboseGC
-
When GC occurs, this option outputs the extended verbosegc information to the JavaVM log file.
This option outputs the information of Eden, Survivor, Tenured, and Metaspace kinds that form the internal areas of GC, as the extended verbosegc information.
- -XX:-HitachiVerboseGC
-
When GC occurs, this option does not output the extended verbosegc information to the JavaVM log file.
Description
Specify whether to output the extended verbosegc information when GC occurs.
- Default value
-
-
-XX:-HitachiVerboseGC
-
Output format (if serial GC is used)
[id] date (Skip Full:full_count, Copy:copy_count) [gc_kind gc_info, gc_time secs][Eden: eden_info][Survivor: survivor_info][Tenured: tenured_info][Metaspace: metaspace_info][class space: class_space_info][cause:cause_info] [User: user_cpu secs] [Sys: system_cpu secs] [IM: jvm_alloc_size, mmap_total_size, malloc_total_size] [TC: thread_count] [DOE: doe_alloc_size, called_count] [CCI: cc_used_sizeK, cc_max_sizeK, cc_infoK]
The following is a description of the output contents:
- id
-
VGC (Identifier of the JavaVM log file)
- date
-
Indicates the date and time for starting GC.
When the -XX:-HitachiVerboseGCPrintDate option is specified, the date is not output.
- full_count
-
Indicates the number of times the output of full GC information is skipped.
This is output when the -XX:HitachiVerboseGCIntervalTime option is specified.
- copy_count
-
Indicates the number of times the output of copy GC information is skipped.
This is output when the -XX:HitachiVerboseGCIntervalTime option is specified.
- gc_kind
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Indicates the GC type. "FullGC" or "GC" is output.
- gc_info
-
Indicates the GC information. The information is output in the following format:
area-length-before-the-GC -> area-length-after-the-GC (area-size)
- gc_time
-
Indicates the elapsed time for GC.
- Eden
-
Indicates the type of eden. "DefNew::Eden" or "ParNew::Eden" is output.
- eden_info
-
Indicates the Eden information. The information is output in the following format:
area-length-before-the-GC -> area-length-after-the-GC (area-size)
- Servivor
-
Indicates the survivor type. "DefNew:: Survivor" or "ParNew::Survivor" is output.
- survivor_info
-
Indicates the Survivor information. The information is output in the following format:
area-length-before-the-GC -> area-length-after-the-GC (area-size)
- Tenured
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Indicates the type of Tenured. "Tenured" is output.
- tenured_info
-
Indicates the Tenured information. The information is output in the following format:
area-length-before-the-GC -> area-length-after-the-GC (area-size)
- metaspace_info
-
Indicates the information about the metaspace area. The information is output in the following format:
size-of-used-area-before-GC (size-of-capacity-before-GC, size-of-committed-area-before-GC) -> size-of-used-area-after-GC (size-of-capacity-after-GC, size-of-committed-area-after-GC)
- class_space_info
-
Indicates the information about the compressed class space. The information is output in the following format:
size-of-used-space-before-GC (size-of-capacity-before-GC, size-of-committed-space-before-GC) -> size-of-used-space-after-GC (size-of-capacity-after-GC, size-of-committed-space-after-GC)
When the -XX:- UseCompressedOops option is specified, this information is not output.
- cause_info
-
Indicates the cause of GC.
When the -XX:-HitachiVerboseGCPrintCause option is specified, this information is not output.
- user_cpu
-
Indicates the CPU time that the GC thread has consumed in the user mode. The unit is in seconds.
If an attempt to obtain the CPU time fails, unknown is displayed as in the case of [User: unknown].
When the -XX:-HitachiVerboseGCCpuTime option is specified, the information is not output.
- system_cpu
-
Indicates the CPU time that the GC thread has consumed in the kernel mode. The unit is in seconds.
If an attempt to obtain the CPU time, unknown is displayed as in the case of [Sys: unknown].
When the -XX:-HitachiVerboseGCCpuTime option is specified, the information is not output.
- jvm_alloc_size
-
Specifies the size of the area currently in use, from the areas being managed in JavaVM (size of the area currently in use, from the total size of mmap_total_size and malloc_total_size).
When the -XX:HitachiVerboseGCPrintJVMInternalMemory option is specified, this information is not output.
- mmap_total_size
-
Specifies the total C heap size allocated for mmap (VirtualAlloc in Windows), from the areas being managed in JavaVM.
When the -XX:-HitachiVerboseGCPrintJVMInternalMemory option is specified, this information is not output.
- malloc_total_size
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Specifies the total C heap size allocated for malloc, from the areas being managed in JavaVM.
When the -XX:-HitachiVerboseGCPrintJVMInternalMemory option is specified, this information is not output.
- thread_count
-
Specifies the number of Java threads.
When the -XX:-HitachiVerboseGCPrintThreadCount option is specified, this information is not output.
- doe_alloc_size
-
Specifies the cumulative heap size allocated by invoking the java.io.File.deleteOnExit()method.
When the -XX:-HitachiVerboseGCPrintDeleteOnExit option is specified, this information is not output.
- called_count
-
Specifies the invocation count of the java.io.File.deleteOnExit() method.
When the -XX:-HitachiVerboseGCPrintDeleteOnExit option is specified, this information is not output.
- cc_used_size
-
Specifies the size of the code cache area used when the GC occurs. The unit is kilobyte.
When the -XX:-PrintCodeCacheInfo option is specified, this information is not output.
- cc_max_size
-
Specifies the maximum size of the code cache area. The unit is kilobyte.
When the -XX:-PrintCodeCacheInfo option is specified, this information is not output.
- cc_info
-
Specifies the maintenance information.
When the -XX:-PrintCodeCacheInfo option is specified, this information is not output.
Output format (if G1 GC is used)
-
VG1 log
[id]date[gc_kind gc_info, gc_time secs][Status: gc_status][G1GC:Eden: eden_info][G1GC:Survivor: survivor_info][G1GC:Tenured: tenured_info][G1GC:Humongous: humongous_info][G1GC:Free: free_info][Metaspace: metaspace_info][class space: class_space_info][cause:cause_info][RegionSize: region_size][Target: target_time secs][Predicted: predicted_time secs][TargetTenured: target_size][Reclaimable: reclaimable_info][User: user_cpu secs] [Sys: system_cpu secs][IM: jvm_alloc_size, mmap_total_size, malloc_total_size][TC: thread_count][DOE: doe_alloc_size, called_count][CCI: cc_used_sizeK, cc_max_sizeK, cc_infoK]
The following is a description of the output contents:
- id
-
VG1 (Identifier of the JavaVM log file)
- date
-
Indicates the date and time for starting GC.
When the -XX:-HitachiVerboseGCPrintDate option is specified, the date is not output.
- gc_kind
-
Indicates the GC type. One of the following strings is output: Full GC, Mixed GC, Young GC, Young GC(initial-mark), CM Remark, or CM Cleanup.
- gc_info
-
Indicates the GC information. The information is output in the following format:
size-of-used-area-before-GC / region-conversion-as-area-size-before-GC (area-size-before-GC) -> area-size-after-GC / region-conversion-as-area-size-after-GC (area-size-after-GC)
In the preceding format, region conversion is a value that rounds up the area size to the size of one region and is expressed as a multiple of the size of one region.
- gc_time
-
Indicates the elapsed time for GC.
- gc_status
-
Indicates the status of GC. Either - or to exhausted is output.
- eden_info
-
Indicates the Eden information. The information is output in the following format:
region-conversion-as-area-size-before-GC(region-conversion-as-maximum-area-size-before-GC) -> region-conversion-as-area-size-after-GC(region-conversion-as-maximum-area-size-after-GC)
In the preceding format, region conversion is a value that rounds up the area size to the size of one region and is expressed as a multiple of the size of one region.
- survivor_info
-
Indicates the Survivor information. The information is output in the following format:
region-conversion-as-area-size-before-GC -> region-conversion-as-area-size-after-GC
In the preceding format, region conversion is a value that rounds up the area size to the size of one region and is expressed as a multiple of the size of one region.
- tenured_info
-
Indicates the Tenured information. The information is output in the following format:
region-conversion-as-area-size-before-GC -> region-conversion-as-area-size-after-GC
In the preceding format, region conversion is a value that rounds up the area size to the size of one region and is expressed as a multiple of the size of one region.
- humongous_info
-
Indicates the Humongous information. The information is output in the following format:
region-conversion-as-area-size-before-GC -> region-conversion-as-area-size-after-GC
In the preceding format, region conversion is a value that rounds up the area size to the size of one region and is expressed as a multiple of the size of one region.
- free_info
-
Indicates the Free information. The information is output in the following format:
region-conversion-as-area-size-before-GC -> region-conversion-as-area-size-after-GC
In the preceding format, region conversion is a value that rounds up the area size to the size of one region and is expressed as a multiple of the size of one region.
- metaspace_info
-
Indicates the information about the metaspace area. The information is output in the following format:
size-of-used-area-before-GC (size-of-capacity-before-GC, size-of-committed-area-before-GC) -> size-of-used-area-after-GC (size-of-capacity-after-GC, size-of-committed-area-after-GC)
- class_space_info
-
Indicates the information about the compressed class space. The information is output in the following format:
size-of-used-area-before-GC (size-of-capacity-before-GC, size-of-committed-area-before-GC) -> size-of-used-area-after-GC (size-of-capacity-after-GC, size-of-committed-area-after-GC)
When the -XX:- UseCompressedOops option is specified, this information is not output.
- cause_info
-
Indicates the cause of GC.
When the -XX:-HitachiVerboseGCPrintCause option is specified, this information is not output.
- region_size
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Indicates the size of one region.
A value in KB is output.
- target_time
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Indicates the target value of the time for which the application will stop during GC.
A value in seconds is output.
- predicted_time
-
Indicates the time for which the application will stop during GC predicted by Java VM.
A value in seconds is output.
Note that if the GC type is Full GC, CM Remark, or CM Cleanup, 0 is output because no prediction is performed.
- target_size
-
Indicates the size of the tenured area subject to mixed GC.
A value in KB is output.
Note that if the GC type is not Mixed GC, 0 is output.
- reclaimable_info
-
Indicates the predicted information about the size of the tenured area that will be reclaimed by mixed GC. The information is output in the following format:
predicted-size-of-reclaimable-area (predicted-ratio-of-reclaimable-area)
Note that predicted information is output only for young GC or mixed GC that immediately follows completion of concurrent marking (CM). In other cases, 0 is output because no prediction is performed.
- user_cpu
-
Indicates the CPU time that the GC thread has consumed in the user mode. The unit is in seconds.
If an attempt to obtain the CPU time fails, unknown is displayed as in the case of [User: unknown].
When the -XX:-HitachiVerboseGCCpuTime option is specified, the information is not output.
- system_cpu
-
Indicates the CPU time that the GC thread has consumed in the kernel mode. The unit is in seconds.
If an attempt to obtain the CPU time fails, unknown is displayed as in the case of [Sys: unknown].
When the -XX:-HitachiVerboseGCCpuTime option is specified, the information is not output.
- jvm_alloc_size
-
Indicates the size of the area currently in use, from the areas being managed in JavaVM (size of the area currently in use, from the total size of mmap_total_size and malloc_total_size).
When the -XX:HitachiVerboseGCPrintJVMInternalMemory option is specified, this information is not output.
- mmap_total_size
-
Indicates the total C heap size allocated for mmap (VirtualAlloc in Windows), from the areas being managed in JavaVM.
When the -XX:-HitachiVerboseGCPrintJVMInternalMemory option is specified, this information is not output.
- malloc_total_size
-
Indicates the total C heap size allocated for malloc, from the areas being managed in JavaVM.
When the -XX:-HitachiVerboseGCPrintJVMInternalMemory option is specified, this information is not output.
- thread_count
-
Indicates the number of Java threads.
When the -XX:-HitachiVerboseGCPrintThreadCount option is specified, this information is not output.
- doe_alloc_size
-
Indicates the cumulative heap size allocated by invoking the java.io.File.deleteOnExit()method.
When the -XX:-HitachiVerboseGCPrintDeleteOnExit option is specified, this information is not output.
- called_count
-
Indicates the invocation count of the java.io.File.deleteOnExit() method.
When the -XX:-HitachiVerboseGCPrintDeleteOnExit option is specified, this information is not output.
- cc_used_size
-
Indicates the size of the code cache area used when the GC occurs. The unit is kilobyte.
When the -XX:-PrintCodeCacheInfo option is specified, this information is not output.
- cc_max_size
-
Indicates the maximum size of the code cache area. The unit is kilobyte.
When the -XX:-PrintCodeCacheInfo option is specified, this information is not output.
- cc_info
-
Indicates the maintenance information.
When the -XX:-PrintCodeCacheInfo option is specified, this information is not output.
-
VCM
[id]date[cm_event][User: user_cpu secs][Sys: sys_cpu secs]
- id
-
VGM (Identifier of the JavaVM log file)
- date
-
Indicates the date and time for starting CM.
When the -XX:-HitachiVerboseGCPrintDate option is specified, the date is not output.
- cm_event
-
Indicates the CM type. One of the following strings is output: Concurrent Root Region Scan Start, Concurrent Root Region Scan End, Concurrent Mark Start, Concurrent Mark End, Concurrent Mark Stop, Concurrent Cleanup Start, or Concurrent Cleanup End.
- user_cpu
-
Indicates the CPU time that all CM threads consumed in the user mode. A value in seconds is output.
When the -XX:-HitachiVerboseGCCpuTime option is specified, the date is not output.
If an attempt to obtain the CPU time fails, unknown is displayed as in the case of [User: unknown].
If the status of CM is Start, 0 is output.
- sys_cpu
-
Indicates the CPU time that all CM threads consumed in the kernel mode. A value in seconds is output.
When the -XX:-HitachiVerboseGCCpuTime option is specified, the date is not output.
If an attempt to obtain the CPU time fails, unknown is displayed as in the case of [Sys: unknown].
If the status of CM is Start, 0 is output.
Examples of output
If serial GC is used:
-
When -XX:HitachiVerboseGCIntervalTime option is specified
[VGC]Wed Mar 17 00:42:30 2004(Skip Full:0,Copy:0)[Full GC 149K->149K(1984K), 0.0786038 secs][DefNew::Eden: 264K->0K(512K)][DefNew::Survivor: 0K->63K(64K)][Tenured: 85K->149K(1408K)][Metaspace: 3634K(4492K, 4492K)->3634K(4492K, 4492K)][class space: 356K(388K, 388K)->356K(388K, 388K)][cause:System.gc][User: 0.0156250 secs][Sys: 0.0312500 secs][IM: 729K, 928K, 0K][TC: 509][DOE: 16K, 170] [CCI: 2301K, 49152K, 2304K]
If G1 GC is used:
-
VG1 log
[VG1]Thu Oct 02 10:38:56.193 2014[Full GC 753K/2048K(8192K)->678K/1024K(8192K), 0.0097901 secs][Status:-][G1GC::Eden: 1024K(2048K)->0K(2048K)][G1GC::Survivor: 0K->0K][G1GC::Tenured: 1024K->1024K][G1GC::Humongous: 0K->0K][G1GC::Free: 6144K->7168K] [Metaspace: 3634K(4492K, 4492K)->3634K(4492K, 4492K)][class space: 356K(388K, 388K)->356K(388K, 388K)] [cause:System.gc][RegionSize: 1024K][Target: 0.2000000 secs][Predicted: 0.0000000 secs][TargetTenured: 0K][Reclaimable: 0K(0.00%)][User: 0.0000000 secs][Sys: 0.0000000 secs][IM: 20459K, 21920K, 0K][TC: 35][DOE: 0K, 0][CCI: 1172K, 245760K, 2496K]
-
VCM log
[VCM]Wed Jul 24 11:45:20 2013[Concurrent Root Region Scan Start][User: 0.0000000 secs][Sys: 0.0000000 secs] [VCM]<Wed Jul 24 11:45:20 2013>[Concurrent Root Region Scan End][User: 0.0126134 secs][Sys: 0.0146961 secs] [VCM]Wed Jul 24 11:45:20 2013[Concurrent Mark Start][User: 0.0000000 secs][Sys: 0.0000000 secs] [VCM]Wed Jul 24 11:45:34 2013[Concurrent Mark End][User: 0.0156250 secs][Sys: 0.2495800 secs]