GNUnet 0.21.0
load.c
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1/*
2 This file is part of GNUnet.
3 Copyright (C) 2010, 2013 GNUnet e.V.
4
5 GNUnet is free software: you can redistribute it and/or modify it
6 under the terms of the GNU Affero General Public License as published
7 by the Free Software Foundation, either version 3 of the License,
8 or (at your option) any later version.
9
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Affero General Public License for more details.
14
15 You should have received a copy of the GNU Affero General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
17
18 SPDX-License-Identifier: AGPL3.0-or-later
19 */
20
27#include "platform.h"
28#include "gnunet_util_lib.h"
29
30
31#define LOG(kind, ...) GNUNET_log_from (kind, "util-load", __VA_ARGS__)
32
37{
42
47
54
61
66
73
79 double load;
80};
81
82
83static void
85{
87 unsigned int n;
88
89 if (load->autodecline.rel_value_us ==
91 return;
93 if (delta.rel_value_us < load->autodecline.rel_value_us)
94 return;
95 if (0 == load->autodecline.rel_value_us)
96 {
97 load->runavg_delay = 0.0;
98 load->load = 0;
99 return;
100 }
101 n = delta.rel_value_us / load->autodecline.rel_value_us;
102 if (n > 16)
103 {
104 load->runavg_delay = 0.0;
105 load->load = 0;
106 return;
107 }
108 while (n > 0)
109 {
110 n--;
111 load->runavg_delay = (load->runavg_delay * 7.0) / 8.0;
112 }
113}
114
115
124struct GNUNET_LOAD_Value *
126{
127 struct GNUNET_LOAD_Value *ret;
128
130 ret->autodecline = autodecline;
131 ret->last_update = GNUNET_TIME_absolute_get ();
132 return ret;
133}
134
135
142void
145{
147 load->autodecline = autodecline;
148}
149
150
156static void
158{
159 double stddev;
160 double avgdel;
161 double sum_val_i;
162 double n;
163 double nm1;
164
165 if (load->cummulative_request_count <= 1)
166 return;
167 /* calculate std dev of latency; we have for n values of "i" that:
168 *
169 * avg = (sum val_i) / n
170 * stddev = (sum (val_i - avg)^2) / (n-1)
171 * = (sum (val_i^2 - 2 avg val_i + avg^2) / (n-1)
172 * = (sum (val_i^2) - 2 avg sum (val_i) + n * avg^2) / (n-1)
173 */sum_val_i = (double) load->cummulative_delay;
174 n = ((double) load->cummulative_request_count);
175 nm1 = n - 1.0;
176 avgdel = sum_val_i / n;
177 stddev =
178 (((double) load->cummulative_squared_delay) - 2.0 * avgdel * sum_val_i
179 + n * avgdel * avgdel) / nm1;
180 if (stddev <= 0)
181 stddev = 0.01; /* must have been rounding error or zero; prevent division by zero */
182 /* now calculate load based on how far out we are from
183 * std dev; or if we are below average, simply assume load zero */
184 if (load->runavg_delay < avgdel)
185 load->load = 0.0;
186 else
187 load->load = (load->runavg_delay - avgdel) / stddev;
188}
189
190
200double
202{
205 return load->load;
206}
207
208
215double
217{
218 double n;
219 double sum_val_i;
220
222 if (load->cummulative_request_count == 0)
223 return 0.0;
224 n = ((double) load->cummulative_request_count);
225 sum_val_i = (double) load->cummulative_delay;
226 return sum_val_i / n;
227}
228
229
236void
238{
239 uint32_t dv;
240
242 load->last_update = GNUNET_TIME_absolute_get ();
243 if (data > 64 * 1024)
244 {
245 /* very large */
246 load->load = 100.0;
247 return;
248 }
249 dv = (uint32_t) data;
250 load->cummulative_delay += dv;
251 load->cummulative_squared_delay += dv * dv;
252 load->cummulative_request_count++;
253 load->runavg_delay = ((load->runavg_delay * 7.0) + dv) / 8.0;
254}
255
256
257/* end of load.c */
static int ret
Final status code.
Definition: gnunet-arm.c:94
static char * data
The data to insert into the dht.
static void load()
Load persistent values from disk.
void GNUNET_LOAD_value_set_decline(struct GNUNET_LOAD_Value *load, struct GNUNET_TIME_Relative autodecline)
Change the value by which the load automatically declines.
Definition: load.c:143
double GNUNET_LOAD_get_average(struct GNUNET_LOAD_Value *load)
Get the average value given to update so far.
Definition: load.c:216
struct GNUNET_LOAD_Value * GNUNET_LOAD_value_init(struct GNUNET_TIME_Relative autodecline)
Create a new load value.
Definition: load.c:125
void GNUNET_LOAD_update(struct GNUNET_LOAD_Value *load, uint64_t data)
Update the current load.
Definition: load.c:237
double GNUNET_LOAD_get_load(struct GNUNET_LOAD_Value *load)
Get the current load.
Definition: load.c:201
#define GNUNET_new(type)
Allocate a struct or union of the given type.
#define GNUNET_TIME_UNIT_FOREVER_REL
Constant used to specify "forever".
struct GNUNET_TIME_Relative GNUNET_TIME_absolute_get_duration(struct GNUNET_TIME_Absolute whence)
Get the duration of an operation as the difference of the current time and the given start time "henc...
Definition: time.c:436
struct GNUNET_TIME_Absolute GNUNET_TIME_absolute_get(void)
Get the current time.
Definition: time.c:111
static void internal_update(struct GNUNET_LOAD_Value *load)
Definition: load.c:84
static void calculate_load(struct GNUNET_LOAD_Value *load)
Recalculate our load value.
Definition: load.c:157
static struct GNUNET_TIME_Relative delta
Definition: speedup.c:36
Values we track for load calculations.
Definition: load.c:37
struct GNUNET_TIME_Relative autodecline
How fast should the load decline if no values are added?
Definition: load.c:41
uint64_t cummulative_request_count
Total number of requests included in the cumulative datastore delay values.
Definition: load.c:65
double runavg_delay
Current running average datastore delay.
Definition: load.c:72
struct GNUNET_TIME_Absolute last_update
Last time this load value was updated by an event.
Definition: load.c:46
uint64_t cummulative_squared_delay
Sum of squares of all datastore delays ever observed (in ms).
Definition: load.c:60
uint64_t cummulative_delay
Sum of all datastore delays ever observed (in ms).
Definition: load.c:53
double load
How high is the load? 0 for below average, otherwise the number of std.
Definition: load.c:79
Time for absolute times used by GNUnet, in microseconds.
Time for relative time used by GNUnet, in microseconds.
uint64_t rel_value_us
The actual value.