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Feature #4472

closed

DTrace full width distribution histograms

Added by Rich Lowe over 7 years ago. Updated over 7 years ago.

Status:
Resolved
Priority:
Normal
Assignee:
-
Category:
DTrace
Start date:
2014-01-14
Due date:
% Done:

90%

Estimated time:
Difficulty:
Medium
Tags:
Gerrit CR:

Description

From the report at Joyent:

Problem:

# dtrace -n 'syscall::write:entry { self->ts = timestamp; }
    syscall::write:return /self->ts/ { @["ns"] = quantize(timestamp - self->ts); self->ts = 0; }'
dtrace: description 'syscall::write:entry ' matched 2 probes
^C

  ns                                                
           value  ------------- Distribution ------------- count    
             256 |                                         0        
             512 |@                                        34       
            1024 |@@                                       47       
            2048 |@@@@@                                    112      
            4096 |@@@@@@@                                  156      
            8192 |@@@@@                                    123      
           16384 |@@@@@@@                                  164      
           32768 |@@@@@@@@                                 190      
           65536 |@@@                                      61       
          131072 |                                         11       
          262144 |                                         1        
          524288 |                                         5        
         1048576 |                                         4        
         2097152 |                                         0   

The greatest row in this case uses 8 '@'s out of 40.

Proposed:

# dtrace -x fullwidth -n 'syscall::write:entry { self->ts = timestamp; }
    syscall::write:return /self->ts/ { @["ns"] = quantize(timestamp - self->ts); self->ts = 0; }'
dtrace: description 'syscall::write:entry ' matched 2 probes
^C

  ns                                                
           value  ------------- Distribution ------------- count    
             256 |                                         0        
             512 |@@@@@                                    34       
            1024 |@@@@@@@@                                 47       
            2048 |@@@@@@@@@@@@@@@@@@@                      112      
            4096 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@           156      
            8192 |@@@@@@@@@@@@@@@@@@@@@@@                  123      
           16384 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@        164      
           32768 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 190      
           65536 |@@@@@@@@@@@                              61       
          131072 |@@@                                      11
          262144 |                                         1        
          524288 |@                                        5        
         1048576 |@                                        4        
         2097152 |                                         0   

This would be an option to make use of the full width of the distribution plot, providing more resolution for finer details. In this example, 5x more resolution.

--

This is being added as the "aggzoom" option.

Actions #1

Updated by Electric Monk over 7 years ago

git commit 33093f5bcdc51014933497dd39374080c1ac5705

Author: Bryan Cantrill <bryan@joyent.com>

4471 DTrace count() with histogram
4472 DTrace full width distribution histograms
4473 DTrace frequency trails
Reviewed by: Dan McDonald <danmcd@omniti.com>
Approved by: Gordon Ross <gwr@nexenta.com>

Actions #2

Updated by Rich Lowe over 7 years ago

  • Status changed from In Progress to Resolved
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