- ttop - show thread CPU usage for JVM
- jps - list JVM processes
- hh - head histogram
- gc - GC tracker
- mx - generic JMX invocation
- stcap - thread dump sampler
- ssa - thread dump file analyzer
- stcpy - copy tool for "dense" thread dump files
Use java -jar sjk.jar --commands for full list of command available.
ttop commands displays list of JVM threads with CPU usage and memory allocation rate details
Usage
> java -jar sjk.jar ttop -help
Usage: ttop [options]
Options:
-f, --filter
Wild card expression to filter threads by name
--help
Default: false
-o, --order
Sort order. Value tags: CPU, USER, SYS, ALLOC, NAME
--password
Password for JMX authentication (only for socket connection)
-p, --pid
JVM process PID
-ri, --report-interval
Interval between CPU usage reports
Default: 10000
-si, --sampler-interval
Interval between polling MBeans
Default: 50
-s, --socket
Socket address for JMX port (host:port)
-n, --top-number
Number of threads to show
Default: 2147483647
--user
User for JMX authentication (only for socket connection)
Example
> java -jar sjk.jar ttop -p 6344 -n 20 -o CPU
2013-09-09T11:32:45.426+0300 Process summary
process cpu=31.08%
application cpu=28.90% (user=6.40% sys=22.49%)
other: cpu=2.19%
heap allocation rate 5260kb/s
[000001] user= 3.12% sys=11.40% alloc= 762kb/s - main
[092018] user= 0.94% sys= 0.47% alloc= 335kb/s - RMI TCP Connection(16)-10.139.211.172
[092016] user= 0.31% sys= 1.56% alloc= 1927kb/s - SVN-WJGGZ
[092007] user= 0.78% sys= 8.75% alloc= 860kb/s - Worker-4863
[092012] user= 0.31% sys= 0.31% alloc= 429kb/s - Worker-4864
[091966] user= 0.16% sys= 0.00% alloc= 90kb/s - Worker-4859
[092022] user= 0.16% sys= 0.00% alloc= 6871b/s - JMX server connection timeout 92022
[000002] user= 0.00% sys= 0.00% alloc= 0b/s - Reference Handler
[000003] user= 0.00% sys= 0.00% alloc= 0b/s - Finalizer
[000004] user= 0.00% sys= 0.00% alloc= 0b/s - Signal Dispatcher
[000005] user= 0.00% sys= 0.00% alloc= 0b/s - Attach Listener
[000009] user= 0.00% sys= 0.00% alloc= 0b/s - Framework Active Thread
[000012] user= 0.00% sys= 0.00% alloc= 0b/s - Framework Event Dispatcher
[000014] user= 0.00% sys= 0.00% alloc= 0b/s - Start Level Event Dispatcher
[000015] user= 0.00% sys= 0.00% alloc= 0b/s - Bundle File Closer
[000018] user= 0.00% sys= 0.00% alloc= 0b/s - [Timer] - Main Queue Handler
[000019] user= 0.00% sys= 0.00% alloc= 0b/s - Worker-JM
[000029] user= 0.00% sys= 0.00% alloc= 0b/s - [ThreadPool Manager] - Idle Thread
[000030] user= 0.00% sys= 0.00% alloc= 0b/s - Java indexing
[000033] user= 0.00% sys= 0.00% alloc= 0b/s - com.google.inject.internal.util.$Finalizer
List local JVM processes in greater details.
> java -jar sjk.jar --help jps
Usage: jps [options]
Options:
-fd, --filter-description
Wild card expression to match process description
-fp, --filter-property
Wild card expressions to match JVM system properties
--help
Default: false
-pd, --process-details
Print custom information related to a process. Following tags can be
used: PID, MAIN, FDQN_MAIN, ARGS, D<sys-prop>, d<sys-prop>, X<jvm-flag>
Extended version of jmap -histo command.
Warning: Heap histogram requires stop the world pause and some options require full GC for target process.
> java -jar sjk.jar --help hh
Usage: hh [options]
Options:
Default: false
--dead
Dead objects histogram
Default: false
--dead-young
Histogram for sample of dead young objects
Default: false
--help
Default: false
--live
Live objects histogram
Default: false
-p, --pid
Process ID
Default: 0
-d, --sample-depth
Used with --dead-young option. Specific time duration to collect young
population.
Default: 10000
-n, --top-number
Show only N top buckets
Default: 2147483647
-X, --verbose
Enable detailed diagnostics
Default: false
--dead option make two subsequent histograms (first for all objects then live only) and calculates difference.
--dead-young options forces full GC then wait for specified period of time (default 10 seconds) then produce --dead histogram.
Idea is following: after full GC there are no garbage in heap. So --dead histogram is showing only objects recenctly allocated (young garbage).
There are two problems with that aprouch though. First, finalizer may prevent some objects to be collected in first full GC.
Second, if young GC is performed between full GC and --dead histogram sampling, garbage population can be skewed.
Command tracks young GC counter and warns if young GC was detected.
Reports GC events from target JVM.
> java -jar sjk.jar --help gc
Usage: gc [options]
Options:
--help
Default: false
-p, --pid
JVM process PID
-s, --socket
Socket address for JMX port (host:port)
MX command allows CLI access to MBean attributes and operations.
> java -jar sjk.jar --help mx
Usage: mx [options]
Options:
-all, --allMatched
Process all matched MBeans
Default: false
-a, --arguments
Arguments for MBean operation invocation
Default: []
-f, --field, --attribute
MBean attribute
* -b, --bean
MBean name
-mc, --call
Invokes MBean method
Default: false
-mg, --get
Retrieves value of MBean attribute
Default: false
--help
Default: false
-mi, --info
Display metadata for MBean
Default: false
-op, --operation
MBean operation name to be called
--password
Password for JMX authentication (only for socket connection)
-p, --pid
JVM process PID
-ms, --set
Sets value for MBean attribute
Default: false
-s, --socket
Socket address for JMX port (host:port)
--user
User for JMX authentication (only for socket connection)
-v, --value
Value to set to attribute
This command have 4 sub commands: -mi, -mg, -ms, -mc - exactly one of them could be used at time.
Example:
> java -jar sjk.jar mx -p 6344 -mi -b java.lang:type=Threading
java.lang:type=Threading
sun.management.ThreadImpl
- Information on the management interface of the MBean
(A) ThreadAllocatedMemoryEnabled : boolean - WRITEABLE
(A) ThreadAllocatedMemorySupported : boolean
(A) ThreadCount : int
...
(O) getThreadAllocatedBytes(long p0) : long
(O) getThreadAllocatedBytes(long[] p0) : long[]
(O) getThreadCpuTime(long[] p0) : long[]
...
Example
> java -jar sjk.jar mx -p 6344 -mg -b java.lang:type=Memory -f HeapMemoryUsage
committed: 419037184
init: 134217728
max: 419037184
used: 356566800
Example
> java -jar sjk.jar mx -p 6344 -ms -b java.lang:type=Threading -f ThreadContentionMonitoringEnabled -v true
> java -jar sjk.jar mx -p 6344 -mc -b java.lang:type=Threading -op dumpAllThreads -a false false
blockedCount|blockedTime|inNative|lockInfo |lockName |lockOwnerId|lockOwnerName|lockedMonitors|lockedSynchronizers|stackTrace |suspended|threadId|threadName |threadState |waitedCount|waitedTime
------------+-----------+--------+----------------------------------------+----------------------------------------+-----------+-------------+--------------+-------------------+----------------------------------------+---------+--------+----------------------------------------+-------------+-----------+----------
2 |0 |false |{className=[I,identityHashCode=17460180}|[I@10a6bd4 |-1 |null | | |{className=java.lang.Object,fileName=...|false |87816 |JMX server connection timeout 87816 |TIMED_WAITING|3 |64
3 |0 |false |{className=[I,identityHashCode=19740445}|[I@12d371d |-1 |null | | |{className=java.lang.Object,fileName=...|false |87810 |JMX server connection timeout 87810 |TIMED_WAITING|4 |42312
2 |0 |false |{className=[I,identityHashCode=24995862}|[I@17d6816 |-1 |null | | |{className=java.lang.Object,fileName=...|false |87809 |JMX server connection timeout 87809 |TIMED_WAITING|3 |59808
3 |0 |false |{className=[I,identityHashCode=3979158} |[I@3cb796 |-1 |null | | |{className=java.lang.Object,fileName=...|false |87808 |JMX server connection timeout 87808 |TIMED_WAITING|4 |70314
0 |0 |false |null |null |-1 |null | | |{className=sun.management.ThreadImpl,...|false |87807 |RMI TCP Connection(13)-10.139.211.172 |RUNNABLE |4 |70040
0 |0 |false |{className=org.eclipse.jface.text.rec...|org.eclipse.jface.text.reconciler.Dir...|-1 |null | | |{className=java.lang.Object,fileName=...|false |87794 |org.eclipse.jdt.internal.ui.text.Java...|TIMED_WAITING|371 |187629
417 |59 |false |{className=org.eclipse.core.internal....|org.eclipse.core.internal.jobs.Worker...|-1 |null | | |{className=java.lang.Object,fileName=...|false |87536 |Worker-4474 |TIMED_WAITING|322 |274933
597 |50 |false |{className=org.eclipse.core.internal....|org.eclipse.core.internal.jobs.Worker...|-1 |null | | |{className=java.lang.Object,fileName=...|false |87477 |Worker-4473 |TIMED_WAITING|484 |317778
477 |53 |false |{className=org.eclipse.core.internal....|org.eclipse.core.internal.jobs.Worker...|-1 |null | | |{className=java.lang.Object,fileName=...|false |87442 |Worker-4469 |TIMED_WAITING|567 |328929
0 |0 |false |{className=java.util.concurrent.locks...|java.util.concurrent.locks.AbstractQu...|-1 |null | | |{className=sun.misc.Unsafe,fileName=U...|false |87417 |RMI Scheduler(0) |TIMED_WAITING|25 |587696
0 |0 |true |null |null |-1 |null | | |{className=java.net.PlainSocketImpl,f...|false |87415 |RMI TCP Accept-0 |RUNNABLE |0 |0
2566 |70 |false |{className=org.eclipse.core.internal....|org.eclipse.core.internal.jobs.Worker...|-1 |null | | |{className=java.lang.Object,fileName=...|false |87339 |Worker-4463 |TIMED_WAITING|3554 |624468
0 |0 |false |{className=java.util.Collections$Sync...|java.util.Collections$SynchronizedRan...|-1 |null | | |{className=java.lang.Object,fileName=...|false |86671 |org.eclipse.wst.sse.ui.internal.recon...|TIMED_WAITING|16434 |632622
0 |0 |false |{className=java.util.Collections$Sync...|java.util.Collections$SynchronizedRan...|-1 |null | | |{className=java.lang.Object,fileName=...|false |86670 |org.eclipse.wst.sse.ui.internal.recon...|TIMED_WAITING|16435 |632621
0 |0 |false |{className=java.util.Collections$Sync...|java.util.Collections$SynchronizedRan...|-1 |null | | |{className=java.lang.Object,fileName=...|false |85508 |org.eclipse.wst.sse.ui.internal.recon...|TIMED_WAITING|21430 |632623
0 |0 |false |{className=org.eclipse.jface.text.rec...|org.eclipse.jface.text.reconciler.Dir...|-1 |null | | |{className=java.lang.Object,fileName=...|false |84797 |org.eclipse.jdt.internal.ui.text.Java...|TIMED_WAITING|23241 |632649
86 |2 |false |{className=org.eclipse.jface.text.rec...|org.eclipse.jface.text.reconciler.Dir...|-1 |null | | |{className=java.lang.Object,fileName=...|false |84712 |org.eclipse.jdt.internal.ui.text.Java...|TIMED_WAITING|23460 |631606
...
stcap commands dumps threads from target process with configured period (or non-stop)
Command example (command below would sample target process for 30 seconds)
> java -jar sjk.jar stcap -p PID -o dump.std
[Stack Capture] Dumps stack traces to file for further processing
Usage: stcap [options]
Options:
-e, --empty
Retain threads without stack trace in dump (ignored by default)
Default: false
-f, --filter
Wild card expression to filter thread by name
Default: .*
--help
Default: false
-l, --limit
Target number of traces to collect, once reached command will terminate
(0 - unlimited)
Default: 0
-m, --match-frame
Frame filter, only traces containing this string will be included in dump
* -o, --output
Name of file to write thread dump to
--password
Password for JMX authentication (only for socket connection)
-p, --pid
JVM process PID
-r, --rotate
If specified output file would be rotated every N traces (0 - do not
rotate)
Default: 0
-i, --sampler-interval
Interval between polling MBeans
Default: 0
-s, --socket
Socket address for JMX port (host:port)
-t, --timeout
Time until command terminate even without enough traces collected
Default: 30000
--user
User for JMX authentication (only for socket connection)
-X, --verbose
Enable detailed diagnostics
Default: false
ssa command's used to analyze thread dump produced by stcap command.
> java -jar sjk.jar ssa --help
[Stack Sample Analyzer] Analyzing stack trace dumps
Usage: ssa [options]
Options:
--categorize
Print summary for provided categorization
Default: false
-cf, --categorizer-file
Path to file with stack trace categorization definition
--commands
Default: false
-co, --csv-output
Output data in CSV format
Default: false
-f, --file
Path to stack dump file
--flame
Export flame graph to SVG format
Default: false
--help
Default: false
--histo
Print frame histogram
Default: false
-nc, --named-class
May be used with some commands to define name stack trace classes
<name>=<filter expression> notation
Default: []
--print
Print traces from file
Default: false
--ssa-help
Additional information about SSA
Default: false
--title
Flame graph title
Default: Flame Graph
-tf, --trace-filter
Apply filter to traces before processing. Use --ssa-help for more details
about filter notation
-tt, --trace-trim
Positional filter trim frames to process. Use --ssa-help for more details
about filter notation
--width
Flame graph width in pixels
Default: 1200
Following subcommands are available:
--print print stack trace in text format.
--histo produces frame histogram from dump file. Below is example of histogram.
Trc N Frm N Term N Frame
21727 57% 21727 0 0% java.lang.Thread.run(Thread.java:662)
16002 42% 16002 16002 42% java.lang.Object.wait(Native Method)
8923 23% 8923 8923 23% java.net.SocketInputStream.socketRead0(Native Method)
8923 23% 8923 0 0% java.net.SocketInputStream.read(SocketInputStream.java:129)
6402 16% 9603 0 0% java.lang.reflect.Method.invoke(Method.java:597)
6402 16% 9603 0 0% sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
6399 16% 6399 0 0% java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:118)
5722 15% 5722 0 0% java.io.BufferedInputStream.fill(BufferedInputStream.java:218)
5722 15% 5722 0 0% java.io.BufferedInputStream.read(BufferedInputStream.java:237)
- Trc N - number of traces containing frame (percentage from total trace count)
- Frm N - number of occurrences for this frame in all traces (same frame may be on stack for multiple times)
- Term N - number of traces terminating with that frame
--flame produces flame graph in SVG format.
--categorize calculate hit count for each category in provided eigther by classification file or via -nc option.
See also SSA documentation page.
This command allow manipulation of thread dump file content. E.g. lumping multiple files to one or filtering content.