Halifax Load Averages - Distribution Analysis

Load Distribution Analysis - [halifax]

Here is an analysis of the load averages for the CCN 'halifax' machine prepared Fri Apr 5 00:02:44 AST 2013 for the previous day. The table and the graphs which are based on the table data represent the distribution of load averages for the specified period.

The 'load average' is the average number of processes (programs) that were waiting to run during the last period. Our long term averages use a five minute average. The daily analysis uses the one minute average.

Example

In the following example ...only 0.1 percent (one tenth of one percent) of the Wednesday, peak usage period, load average readings (taken once per minute) were less than 1.0 .

 Load    Running      Wed    Peak     Wed
Average    24 hr    24 hr     (1)    Peak
=========================================
   1        20.1     16.4     0.0     0.1
   2        14.7      8.2     0.8     4.9
   3        15.5      9.2     9.9    14.2
   4        13.4     11.6    15.4    12.8
   5         9.3     12.0    16.5    12.1
-----------------------------------------
 % < 5 =    73.0     57.4    42.6    44.1
-----------------------------------------
 % > 5 =    27.0     42.6    57.4    55.9
-----------------------------------------
<snip...>

Note: (1) - This is the running average for Wed. peak usage periods
since logging started.

Again in the above example, during the Wed. peak utilization period, 55.9% of the one minute load average readings were over 5.0. (...a very bad day)

The table data represents the distribution of load averages for:

running averages (7x24 hr) since logging started (col 2)
running 24 hr averages for all Wednesday(s) since logging started (col 3)
running (peak usage (noon-midnight)) averages for all Wednesday(s) since logging started (col 4)
(peak usage (noon-midnight)) averages for yesterday (Wednesday) (col 5)


 Load     Running     Wed    Peak     Wed
Average    24 hr    24 hr    (1)     Peak
=========================================
 < 1        49.6     48.4    49.9    92.1
   2        17.9     17.5    17.4     7.8
   3        12.0     12.1    11.8     0.1
   4         6.7      6.9     7.0     0.0
   5         3.9      4.0     3.7     0.0
-----------------------------------------
% < 5 =     90.1     88.9    89.8   100.0
-----------------------------------------
% > 5 =      9.9     11.1    10.2     0.0
-----------------------------------------
   6         2.4      2.7     2.5     0.0
   7         1.6      1.8     1.5     0.0
   8         1.1      1.3     1.2     0.0
   9         0.8      1.0     0.9     0.0
  10         0.6      0.7     0.7     0.0
12.5         1.2      1.4     1.3     0.0
  15         0.9      0.8     0.9     0.0
17.5         0.6      0.8     0.7     0.0
  20         0.3      0.3     0.3     0.0
  25         0.3      0.1     0.2     0.0
  30         0.1      0.0     0.0     0.0
< 40         0.1      0.0     0.0     0.0
 40+         0.0      0.1     0.0     0.0
=========================================
Total      100.1     99.9   100.0   100.0
-----------------------------------------

The best situation would be if the lines on the following graphs were flat above 5.0 and very near '0'.

This graph shows the long term distribution analysis of load averages on the CCN 'halifax' machine. The display includes:

(red) the (7x) 24 hour load average distribution since this logging began, January 1999.
(green) the load average distribution for this 'day of the week' since logging began. We compare Tuesday with Tuesday, Sunday with Sunday...
(blue) the load average distribution for the 12 (noon) - 12 (midnight) peak usage period since logging began.

This graph shows:

(red) the long term distribution of load averages for this peak usage period for this same 'day of the week' (same as 'blue' on graph above...)
(green) Wednesday's distribution analysis of load averages for the peak usage period 12 (noon) - 12 (midnight), and

Previous report - comments to: userhelp

This document generated by: halifax:CS_ROOT/cronbin/load_dist_analysis2