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ssa command

ssa command's used to analyze data files conating Java thread sampling information.

Currently supported formats are

  • native SJK super comressed binary format produced by stcap command
  • VisualVM thread sampler snapshot files
  • Java Flight Recorder recordings
  • jstack thread dumps

Usage

> java -jar sjk.jar ssa --help
[Stack Sample Analyzer] Analyzing stack trace dumps
Usage: ssa [options]
  Options:
		--by-term
	   Sort frame histogram by terminal count
	   Default: false
		--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
       Use <name>=<filter expression> notation
	   Default: []
		--parsers-info
	   Print parsers available in classpath
	   Default: false
		--print
	   Print traces from file
	   Default: false
	-rc, --rainbow
	   List of filters for rainbow coloring
		--ssa-help
	   Additional information about SSA
	   Default: false
	-si, --summary-info
	   List of summaries
		--thread-info
	   Per thread info summary
	   Default: false
	-tn, --thread-name
	   Thread name filter (Java RegEx syntax)
	-tr, --time-range
	   Time range filter
	-tz, --time-zone
	   Time zone used for timestamps and time ranges
	   Default: UTC
		--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
	-X, --verbose
	   Enable detailed diagnostics
	   Default: false
		--width
	   Flame graph width in pixels
	   Default: 1200

Subcommands

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 (see also flame command).

--categorize calculate hit count for each category in provided eigther by classification file or via -nc option.

See also SSA documentation page.