[rrd-developers] [PATCH] set smoothing window
Evan Miller
emiller at imvu.com
Sat Sep 8 04:07:57 CEST 2007
Here's a patch to allow the smoothing window size in the archive
definition. Old format:
RRA:SEASONAL:seasonal period:gamma:rra-num
RRA:DEVSEASONAL:seasonal period:gamma:rra-num
New (backward-compatible) format:
RRA:SEASONAL:seasonal period:gamma:rra-num[:smoothing window]
RRA:DEVSEASONAL:seasonal period:gamma:rra-num[:smoothing window]
By default it's set to 0.05 (same as now), which means 5% of a season is
used for the running average. Setting "smoothing window" to 0 will
disable the running-average smoother altogether.
Let me know if I've forgotten anything...
Evan
-------------- next part --------------
Index: src/rrd_hw.c
===================================================================
--- src/rrd_hw.c (revision 1199)
+++ src/rrd_hw.c (working copy)
@@ -139,7 +139,9 @@
rrd_value_t *working_average;
rrd_value_t *baseline;
- offset = floor(0.025 * row_count);
+ offset = floor(rrd->rra_def[rra_idx].
+ par[RRA_seasonal_smoothing_window].
+ u_val / 2 * row_count);
if (offset == 0)
return 0; /* no smoothing */
Index: src/rrd_format.h
===================================================================
--- src/rrd_format.h (revision 1199)
+++ src/rrd_format.h (working copy)
@@ -194,13 +194,15 @@
enum rra_par_en { RRA_cdp_xff_val = 0, /* what part of the consolidated
* datapoint must be known, to produce a
* valid entry in the rra */
- RRA_hw_alpha,
+ /* CF_HWPREDICT: */
+ RRA_hw_alpha = 1,
/* exponential smoothing parameter for the intercept in
* the Holt-Winters prediction algorithm. */
- RRA_hw_beta,
+ RRA_hw_beta = 2,
/* exponential smoothing parameter for the slope in
* the Holt-Winters prediction algorithm. */
- RRA_dependent_rra_idx,
+
+ RRA_dependent_rra_idx = 3,
/* For CF_HWPREDICT: index of the RRA with the seasonal
* effects of the Holt-Winters algorithm (of type
* CF_SEASONAL).
@@ -212,22 +214,30 @@
* Holt-Winters prediction (of type CF_HWPREDICT).
* For CF_FAILURES: index of the CF_DEVSEASONAL array.
* */
- RRA_seasonal_smooth_idx,
- /* For CF_SEASONAL and CF_DEVSEASONAL:
- * an integer between 0 and row_count - 1 which
+
+ /* CF_SEASONAL and CF_DEVSEASONAL: */
+ RRA_seasonal_gamma = 1,
+ /* exponential smoothing parameter for seasonal effects. */
+
+ RRA_seasonal_smoothing_window = 2,
+ /* fraction of the season to include in the running average
+ * smoother */
+
+ /* RRA_dependent_rra_idx = 3, */
+
+ RRA_seasonal_smooth_idx = 4,
+ /* an integer between 0 and row_count - 1 which
* is index in the seasonal cycle for applying
* the period smoother. */
- RRA_failure_threshold,
+
+ /* CF_FAILURES: */
+ RRA_delta_pos = 1, /* confidence bound scaling parameters */
+ RRA_delta_neg = 2,
+ /* RRA_dependent_rra_idx = 3, */
+ RRA_window_len = 4,
+ RRA_failure_threshold = 5,
/* For CF_FAILURES, number of violations within the last
* window required to mark a failure. */
- RRA_seasonal_gamma = RRA_hw_alpha,
- /* exponential smoothing parameter for seasonal effects.
- * */
- RRA_delta_pos = RRA_hw_alpha,
- RRA_delta_neg = RRA_hw_beta,
- /* confidence bound scaling parameters for the
- * the FAILURES RRA. */
- RRA_window_len = RRA_seasonal_smooth_idx
};
/* For CF_FAILURES, the length of the window for measuring
Index: src/rrd_create.c
===================================================================
--- src/rrd_create.c (revision 1199)
+++ src/rrd_create.c (working copy)
@@ -264,6 +264,8 @@
/* initialize some parameters */
rrd.rra_def[rrd.stat_head->rra_cnt].
par[RRA_seasonal_gamma].u_val = 0.1;
+ rrd.rra_def[rrd.stat_head->rra_cnt].
+ par[RRA_seasonal_smoothing_window].u_val = 0.05;
/* fall through */
case CF_DEVPREDICT:
rrd.rra_def[rrd.stat_head->rra_cnt].
@@ -420,6 +422,13 @@
par[RRA_dependent_rra_idx].u_cnt =
atoi(token) - 1;
break;
+ case CF_DEVSEASONAL:
+ case CF_SEASONAL:
+ rrd.rra_def[rrd.stat_head->rra_cnt].
+ par[RRA_seasonal_smoothing_window].u_val = atof(token);
+ if (atof(token) < 0.0 || atof(token) > 1.0)
+ rrd_set_error("Invalid smoothing window: must be between 0 and 1");
+ break;
case CF_HWPREDICT:
case CF_MHWPREDICT:
/* length of the associated CF_SEASONAL and CF_DEVSEASONAL arrays. */
Index: src/rrd_tune.c
===================================================================
--- src/rrd_tune.c (revision 1199)
+++ src/rrd_tune.c (working copy)
@@ -88,6 +88,8 @@
{"beta", required_argument, 0, 'y'},
{"gamma", required_argument, 0, 'z'},
{"gamma-deviation", required_argument, 0, 'v'},
+ {"smoothing-window", required_argument, 0, 's'},
+ {"smoothing-window-deviation", required_argument, 0, 'S'},
{"aberrant-reset", required_argument, 0, 'b'},
{0, 0, 0, 0}
};
@@ -296,6 +298,18 @@
return -1;
}
break;
+ case 's':
+ if (set_hwarg(&rrd, CF_SEASONAL, RRA_seasonal_smoothing_window, optarg)) {
+ rrd_free(&rrd);
+ return -1;
+ }
+ break;
+ case 'S':
+ if (set_hwarg(&rrd, CF_DEVSEASONAL, RRA_seasonal_smoothing_window, optarg)) {
+ rrd_free(&rrd);
+ return -1;
+ }
+ break;
case '?':
if (optopt != 0)
rrd_set_error("unknown option '%c'", optopt);
Index: doc/rrdcreate.pod
===================================================================
--- doc/rrdcreate.pod (revision 1199)
+++ doc/rrdcreate.pod (working copy)
@@ -238,11 +238,11 @@
=item *
-B<RRA:>I<SEASONAL>B<:>I<seasonal period>B<:>I<gamma>B<:>I<rra-num>
+B<RRA:>I<SEASONAL>B<:>I<seasonal period>B<:>I<gamma>B<:>I<rra-num>[B<:>I<smoothing fraction>]
=item *
-B<RRA:>I<DEVSEASONAL>B<:>I<seasonal period>B<:>I<gamma>B<:>I<rra-num>
+B<RRA:>I<DEVSEASONAL>B<:>I<seasonal period>B<:>I<gamma>B<:>I<rra-num>[B<:>I<smoothing fraction>]
=item *
@@ -342,6 +342,13 @@
be the same for both. Note that I<gamma> can also be changed via the
B<RRDtool> I<tune> command.
+I<smoothing fraction> specifies the fraction of a season that should be
+averaged around each point. By default, the value of I<smoothing fraction> is
+0.05, which means each value in SEASONAL and DEVSEASONAL will be occasionally
+replaced by averaging it with its (I<seasonal period>*0.05) nearest neighbors.
+Setting I<smoothing fraction> to zero will disable the running-average smoother
+altogether.
+
I<rra-num> provides the links between related B<RRAs>. If HWPREDICT is
specified alone and the other B<RRAs> are created implicitly, then
there is no need to worry about this argument. If B<RRAs> are created
Index: doc/rrdtune.pod
===================================================================
--- doc/rrdtune.pod (revision 1199)
+++ doc/rrdtune.pod (working copy)
@@ -18,6 +18,8 @@
S<[B<--beta> I<adaption-parameter>]>
S<[B<--gamma> I<adaption-parameter>]>
S<[B<--gamma-deviation> I<adaption-parameter>]>
+S<[B<--smoothing-window> I<fraction-of-season>]>
+S<[B<--smoothing-window-deviation> I<fraction-of-season>]>
S<[B<--aberrant-reset> I<ds-name>]>
=head1 DESCRIPTION
@@ -117,6 +119,16 @@
Alter the seasonal deviation adaptation parameter for the DEVSEASONAL
B<RRA>. This parameter must be between 0 and 1.
+=item S<B<--smoothing-window> I<fraction-of-season>>
+
+Alter the size of the smoothing window for the SEASONAL B<RRA>. This must
+be between 0 and 1.
+
+=item S<B<--smoothing-window-deviation> I<fraction-of-season>>
+
+Alter the size of the smoothing window for the DEVSEASONAL B<RRA>. This must
+be between 0 and 1.
+
=item S<B<--aberrant-reset> I<ds-name>>
This option causes the aberrant behavior detection algorithm to reset
More information about the rrd-developers
mailing list