When you need to attach process to jmap you might get following error here i have described how we can avoid that.
Run fllowing to get process ID
:jps
3252 Bootstrap
3513 Jps
Then run following to execute jmap
:jmap -heap:format=b 3252
Attaching to process ID 3252, please wait...
Error attaching to process: sun.jvm.hotspot.debugger.DebuggerException: Can't attach to the process
Then to avoid error run following
:echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope
Then run again above command
:jmap -heap:format=b 3252
Attaching to process ID 3252, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 17.0-b16
using thread-local object allocation.
Parallel GC with 4 thread(s)
Heap Configuration:
MinHeapFreeRatio = 40
MaxHeapFreeRatio = 70
MaxHeapSize = 1073741824 (1024.0MB)
NewSize = 1310720 (1.25MB)
MaxNewSize = 17592186044415 MB
OldSize = 5439488 (5.1875MB)
NewRatio = 2
SurvivorRatio = 8
PermSize = 21757952 (20.75MB)
MaxPermSize = 268435456 (256.0MB)
Heap Usage:
PS Young Generation
Eden Space:
capacity = 263847936 (251.625MB)
used = 226730648 (216.2271957397461MB)
free = 37117288 (35.397804260253906MB)
85.93231822742021% used
From Space:
capacity = 36372480 (34.6875MB)
used = 16924568 (16.140525817871094MB)
free = 19447912 (18.546974182128906MB)
46.53124560106982% used
To Space:
capacity = 40763392 (38.875MB)
used = 0 (0.0MB)
free = 40763392 (38.875MB)
0.0% used
PS Old Generation
capacity = 333053952 (317.625MB)
used = 179019752 (170.7265396118164MB)
free = 154034200 (146.8984603881836MB)
53.75097665858053% used
PS Perm Generation
capacity = 151519232 (144.5MB)
used = 93595192 (89.25933074951172MB)
free = 57924040 (55.24066925048828MB)
61.771163148451016% used
You will see correct output
Run fllowing to get process ID
:jps
3252 Bootstrap
3513 Jps
Then run following to execute jmap
:jmap -heap:format=b 3252
Attaching to process ID 3252, please wait...
Error attaching to process: sun.jvm.hotspot.debugger.DebuggerException: Can't attach to the process
Then to avoid error run following
:echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope
Then run again above command
:jmap -heap:format=b 3252
Attaching to process ID 3252, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 17.0-b16
using thread-local object allocation.
Parallel GC with 4 thread(s)
Heap Configuration:
MinHeapFreeRatio = 40
MaxHeapFreeRatio = 70
MaxHeapSize = 1073741824 (1024.0MB)
NewSize = 1310720 (1.25MB)
MaxNewSize = 17592186044415 MB
OldSize = 5439488 (5.1875MB)
NewRatio = 2
SurvivorRatio = 8
PermSize = 21757952 (20.75MB)
MaxPermSize = 268435456 (256.0MB)
Heap Usage:
PS Young Generation
Eden Space:
capacity = 263847936 (251.625MB)
used = 226730648 (216.2271957397461MB)
free = 37117288 (35.397804260253906MB)
85.93231822742021% used
From Space:
capacity = 36372480 (34.6875MB)
used = 16924568 (16.140525817871094MB)
free = 19447912 (18.546974182128906MB)
46.53124560106982% used
To Space:
capacity = 40763392 (38.875MB)
used = 0 (0.0MB)
free = 40763392 (38.875MB)
0.0% used
PS Old Generation
capacity = 333053952 (317.625MB)
used = 179019752 (170.7265396118164MB)
free = 154034200 (146.8984603881836MB)
53.75097665858053% used
PS Perm Generation
capacity = 151519232 (144.5MB)
used = 93595192 (89.25933074951172MB)
free = 57924040 (55.24066925048828MB)
61.771163148451016% used
You will see correct output
Hi Sanjeewa,
ReplyDeleteI was facing same issue, but command jmap -heap:format=b 3252 created a file heap.bin which is not human readable.
Can you help ?