Adding upstream version 1.36.0.upstream/1.36.0

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

4 files changed, 258 insertions, 0 deletions

diff --git a/web/api/queries/percentile/Makefile.am b/web/api/queries/percentile/Makefile.am
new file mode 100644
index 000000000..161784b8f
--- /dev/null
+++ b/web/api/queries/percentile/Makefile.am
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+AUTOMAKE_OPTIONS = subdir-objects
+MAINTAINERCLEANFILES = $(srcdir)/Makefile.in
+
+dist_noinst_DATA = \
+    README.md \
+    $(NULL)
diff --git a/web/api/queries/percentile/README.md b/web/api/queries/percentile/README.md
new file mode 100644
index 000000000..70afc7420
--- /dev/null
+++ b/web/api/queries/percentile/README.md
@@ -0,0 +1,58 @@
+<!--
+title: "Percentile"
+description: "Use percentile in API queries and health entities to find the 'percentile' value from a sample, eliminating any unwanted spikes in the returned metrics."
+custom_edit_url: https://github.com/netdata/netdata/edit/master/web/api/queries/percentile/README.md
+-->
+
+# Percentile
+
+The percentile is the average value of a series using only the smaller N percentile of the values.
+(a population or a probability distribution).
+
+Netdata applies linear interpolation on the last point, if the percentile requested does not give a round number of
+points.
+
+The following percentile aliases are defined:
+
+- `percentile25`
+- `percentile50`
+- `percentile75`
+- `percentile80`
+- `percentile90`
+- `percentile95`
+- `percentile97`
+- `percentile98`
+- `percentile99`
+
+The default `percentile` is an alias for `percentile95`.
+Any percentile may be requested using the `group_options` query parameter.
+
+## how to use
+
+Use it in alarms like this:
+
+```
+ alarm: my_alarm
+    on: my_chart
+lookup: percentile95 -1m unaligned of my_dimension
+  warn: $this > 1000
+```
+
+`percentile` does not change the units. For example, if the chart units is `requests/sec`, the result
+will be again expressed in the same units. 
+
+It can also be used in APIs and badges as `&group=percentile` in the URL and the additional parameter `group_options`
+may be used to request any percentile (e.g. `&group=percentile&group_options=96`).
+
+## Examples
+
+Examining last 1 minute `successful` web server responses:
+
+-   ![](https://registry.my-netdata.io/api/v1/badge.svg?chart=web_log_nginx.response_statuses&options=unaligned&dimensions=success&group=min&after=-60&label=min)
+-   ![](https://registry.my-netdata.io/api/v1/badge.svg?chart=web_log_nginx.response_statuses&options=unaligned&dimensions=success&group=average&after=-60&label=average)
+-   ![](https://registry.my-netdata.io/api/v1/badge.svg?chart=web_log_nginx.response_statuses&options=unaligned&dimensions=success&group=percentile95&after=-60&label=percentile95&value_color=orange)
+-   ![](https://registry.my-netdata.io/api/v1/badge.svg?chart=web_log_nginx.response_statuses&options=unaligned&dimensions=success&group=max&after=-60&label=max)
+
+## References
+
+-   <https://en.wikipedia.org/wiki/Percentile>.
diff --git a/web/api/queries/percentile/percentile.c b/web/api/queries/percentile/percentile.c
new file mode 100644
index 000000000..88f8600dd
--- /dev/null
+++ b/web/api/queries/percentile/percentile.c
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "percentile.h"
+
+// ----------------------------------------------------------------------------
+// median
+
+struct grouping_percentile {
+    size_t series_size;
+    size_t next_pos;
+    NETDATA_DOUBLE percent;
+
+    NETDATA_DOUBLE *series;
+};
+
+static void grouping_create_percentile_internal(RRDR *r, const char *options, NETDATA_DOUBLE def) {
+    long entries = r->group;
+    if(entries < 10) entries = 10;
+
+    struct grouping_percentile *g = (struct grouping_percentile *)onewayalloc_callocz(r->internal.owa, 1, sizeof(struct grouping_percentile));
+    g->series = onewayalloc_mallocz(r->internal.owa, entries * sizeof(NETDATA_DOUBLE));
+    g->series_size = (size_t)entries;
+
+    g->percent = def;
+    if(options && *options) {
+        g->percent = str2ndd(options, NULL);
+        if(!netdata_double_isnumber(g->percent)) g->percent = 0.0;
+        if(g->percent < 0.0) g->percent = 0.0;
+        if(g->percent > 100.0) g->percent = 100.0;
+    }
+
+    g->percent = g->percent / 100.0;
+    r->internal.grouping_data = g;
+}
+
+void grouping_create_percentile25(RRDR *r, const char *options) {
+    grouping_create_percentile_internal(r, options, 25.0);
+}
+void grouping_create_percentile50(RRDR *r, const char *options) {
+    grouping_create_percentile_internal(r, options, 50.0);
+}
+void grouping_create_percentile75(RRDR *r, const char *options) {
+    grouping_create_percentile_internal(r, options, 75.0);
+}
+void grouping_create_percentile80(RRDR *r, const char *options) {
+    grouping_create_percentile_internal(r, options, 80.0);
+}
+void grouping_create_percentile90(RRDR *r, const char *options) {
+    grouping_create_percentile_internal(r, options, 90.0);
+}
+void grouping_create_percentile95(RRDR *r, const char *options) {
+    grouping_create_percentile_internal(r, options, 95.0);
+}
+void grouping_create_percentile97(RRDR *r, const char *options) {
+    grouping_create_percentile_internal(r, options, 97.0);
+}
+void grouping_create_percentile98(RRDR *r, const char *options) {
+    grouping_create_percentile_internal(r, options, 98.0);
+}
+void grouping_create_percentile99(RRDR *r, const char *options) {
+    grouping_create_percentile_internal(r, options, 99.0);
+}
+
+// resets when switches dimensions
+// so, clear everything to restart
+void grouping_reset_percentile(RRDR *r) {
+    struct grouping_percentile *g = (struct grouping_percentile *)r->internal.grouping_data;
+    g->next_pos = 0;
+}
+
+void grouping_free_percentile(RRDR *r) {
+    struct grouping_percentile *g = (struct grouping_percentile *)r->internal.grouping_data;
+    if(g) onewayalloc_freez(r->internal.owa, g->series);
+
+    onewayalloc_freez(r->internal.owa, r->internal.grouping_data);
+    r->internal.grouping_data = NULL;
+}
+
+void grouping_add_percentile(RRDR *r, NETDATA_DOUBLE value) {
+    struct grouping_percentile *g = (struct grouping_percentile *)r->internal.grouping_data;
+
+    if(unlikely(g->next_pos >= g->series_size)) {
+        g->series = onewayalloc_doublesize( r->internal.owa, g->series, g->series_size * sizeof(NETDATA_DOUBLE));
+        g->series_size *= 2;
+    }
+
+    g->series[g->next_pos++] = value;
+}
+
+NETDATA_DOUBLE grouping_flush_percentile(RRDR *r, RRDR_VALUE_FLAGS *rrdr_value_options_ptr) {
+    struct grouping_percentile *g = (struct grouping_percentile *)r->internal.grouping_data;
+
+    NETDATA_DOUBLE value;
+    size_t available_slots = g->next_pos;
+
+    if(unlikely(!available_slots)) {
+        value = 0.0;
+        *rrdr_value_options_ptr |= RRDR_VALUE_EMPTY;
+    }
+    else if(available_slots == 1) {
+        value = g->series[0];
+    }
+    else {
+        sort_series(g->series, available_slots);
+
+        NETDATA_DOUBLE min = g->series[0];
+        NETDATA_DOUBLE max = g->series[available_slots - 1];
+
+        if (min != max) {
+            size_t slots_to_use = (size_t)((NETDATA_DOUBLE)available_slots * g->percent);
+            if(!slots_to_use) slots_to_use = 1;
+
+            NETDATA_DOUBLE percent_to_use = (NETDATA_DOUBLE)slots_to_use / (NETDATA_DOUBLE)available_slots;
+            NETDATA_DOUBLE percent_delta = g->percent - percent_to_use;
+
+            NETDATA_DOUBLE percent_interpolation_slot = 0.0;
+            NETDATA_DOUBLE percent_last_slot = 0.0;
+            if(percent_delta > 0.0) {
+                NETDATA_DOUBLE percent_to_use_plus_1_slot = (NETDATA_DOUBLE)(slots_to_use + 1) / (NETDATA_DOUBLE)available_slots;
+                NETDATA_DOUBLE percent_1slot = percent_to_use_plus_1_slot - percent_to_use;
+
+                percent_interpolation_slot = percent_delta / percent_1slot;
+                percent_last_slot = 1 - percent_interpolation_slot;
+            }
+
+            int start_slot, stop_slot, step, last_slot, interpolation_slot;
+            if(min >= 0.0 && max >= 0.0) {
+                start_slot = 0;
+                stop_slot = start_slot + (int)slots_to_use;
+                last_slot = stop_slot - 1;
+                interpolation_slot = stop_slot;
+                step = 1;
+            }
+            else {
+                start_slot = (int)available_slots - 1;
+                stop_slot = start_slot - (int)slots_to_use;
+                last_slot = stop_slot + 1;
+                interpolation_slot = stop_slot;
+                step = -1;
+            }
+
+            value = 0.0;
+            for(int slot = start_slot; slot != stop_slot ; slot += step)
+                value += g->series[slot];
+
+            size_t counted = slots_to_use;
+            if(percent_interpolation_slot > 0.0 && interpolation_slot >= 0 && interpolation_slot < (int)available_slots) {
+                value += g->series[interpolation_slot] * percent_interpolation_slot;
+                value += g->series[last_slot] * percent_last_slot;
+                counted++;
+            }
+
+            value = value / (NETDATA_DOUBLE)counted;
+        }
+        else
+            value = min;
+    }
+
+    if(unlikely(!netdata_double_isnumber(value))) {
+        value = 0.0;
+        *rrdr_value_options_ptr |= RRDR_VALUE_EMPTY;
+    }
+
+    //log_series_to_stderr(g->series, g->next_pos, value, "percentile");
+
+    g->next_pos = 0;
+
+    return value;
+}
diff --git a/web/api/queries/percentile/percentile.h b/web/api/queries/percentile/percentile.h
new file mode 100644
index 000000000..709717ebd
--- /dev/null
+++ b/web/api/queries/percentile/percentile.h
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef NETDATA_API_QUERIES_PERCENTILE_H
+#define NETDATA_API_QUERIES_PERCENTILE_H
+
+#include "../query.h"
+#include "../rrdr.h"
+
+extern void grouping_create_percentile25(RRDR *r, const char *options);
+extern void grouping_create_percentile50(RRDR *r, const char *options);
+extern void grouping_create_percentile75(RRDR *r, const char *options);
+extern void grouping_create_percentile80(RRDR *r, const char *options);
+extern void grouping_create_percentile90(RRDR *r, const char *options);
+extern void grouping_create_percentile95(RRDR *r, const char *options);
+extern void grouping_create_percentile97(RRDR *r, const char *options);
+extern void grouping_create_percentile98(RRDR *r, const char *options);
+extern void grouping_create_percentile99(RRDR *r, const char *options );
+extern void grouping_reset_percentile(RRDR *r);
+extern void grouping_free_percentile(RRDR *r);
+extern void grouping_add_percentile(RRDR *r, NETDATA_DOUBLE value);
+extern NETDATA_DOUBLE grouping_flush_percentile(RRDR *r, RRDR_VALUE_FLAGS *rrdr_value_options_ptr);
+
+#endif //NETDATA_API_QUERIES_PERCENTILE_H