mixin: explain "not in Go" goroutines, allow a compact dashboard (#2671)

Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Signed-off-by: Jan-Otto Kröpke <mail@jkroepke.de>

contrib/mixin/README.md

@@ -257,7 +257,8 @@ The checked-in JSON remains the reference for the rendered dashboard, including
 queries, IDs, variables, annotations, transformations, and tab/row layout.
 `mise run check-dashboards` regenerates it and runs `git diff --exit-code`, displaying
 any drift. CI runs that check before the mixin tests. The dashboard uses its own
-variables for selectors; from `_config` it reads only `collectors`.
+variables for selectors; from `_config` it reads only `collectors`,
+`enableFleetTab` and `enableOverviewTab`.
 
 ### Collectors
 
@@ -279,6 +280,18 @@ object with `collectors:` enables only the listed collectors:
 }.grafanaDashboards['windows-exporter.json']
 ```
 
+The Fleet and Overview tabs combine several collectors. For a compact
+dashboard with only the collector tabs and the Exporter tab, turn them off:
+
+```jsonnet
+(import 'mixin.libsonnet') {
+  _config+:: {
+    enableFleetTab: false,
+    enableOverviewTab: false,
+  },
+}.grafanaDashboards['windows-exporter.json']
+```
+
 The committed sample dashboard enables every collector. The Fleet hosts table
 always queries the default collectors; its columns stay empty for collectors
 that are turned off. Tab sources are

contrib/mixin/config.libsonnet

@@ -11,6 +11,11 @@
     // Requires the time collector with its ntp subcollector enabled.
     enableTime: false,
 
+    // Dashboard tabs that don't belong to a single collector. Turn them off
+    // for a compact dashboard with only the collector tabs.
+    enableFleetTab: true,
+    enableOverviewTab: true,
+
     // Collectors enabled on the windows_exporter targets, by collector name.
     // The dashboard only renders the tabs, rows and panels of enabled
     // collectors. The defaults match the exporter's default collectors.

contrib/mixin/dashboards/exporter.libsonnet

@@ -495,7 +495,7 @@ function(on)
       }),
 
       b.panel.new(107, 'Goroutines by state', 'timeseries')
-      + b.panel.withDescription('Steady growth of goroutines points to a goroutine leak. Goroutines that stay "not in Go" sit in a system call, for example a collector waiting on WMI or PDH. The states need an exporter build with the Go scheduler metrics; the total line works with every build.')
+      + b.panel.withDescription('Steady growth of goroutines points to a goroutine leak. Goroutines that stay "not in Go" sit in a system call, for example a collector waiting on WMI or PDH. The states need an exporter build with the Go scheduler metrics; the total line works with every build. Since 0.32, "not in Go" keeps growing even without a leak: a Go runtime bug (golang/go#82136) counts each WMI callback from a Windows thread once and never subtracts it. Use the total line to spot a leak instead.')
       + b.panel.withQueries([
         b.query.new('go_sched_goroutines_running_goroutines{job=~"$job", instance="$instance"}', 'A')
         + b.query.withLegendFormat('running'),

contrib/mixin/dashboards/windows-exporter.libsonnet

@@ -1,7 +1,9 @@
 local b = import 'builders.libsonnet';
 local dashboard = b.dashboard;
 
-// config.collectors selects the collectors the dashboard renders, see config.libsonnet.
+// config.collectors selects the collectors the dashboard renders, and
+// config.enableFleetTab and config.enableOverviewTab the tabs across
+// collectors, see config.libsonnet.
 function(config)
   local known = std.objectFields((import '../config.libsonnet')._config.collectors);
   local unknown = std.setDiff(std.objectFields(config.collectors), known);
@@ -15,8 +17,8 @@ function(config)
   local tabs = [
     tab
     for tab in [
-      (import 'fleet.libsonnet')(on, config),
-      (import 'overview.libsonnet')(on),
+      if config.enableFleetTab then (import 'fleet.libsonnet')(on, config),
+      if config.enableOverviewTab then (import 'overview.libsonnet')(on),
       (import 'cpu.libsonnet')(on),
       (import 'memory.libsonnet')(on),
       (import 'disk.libsonnet')(on),
@@ -31,7 +33,7 @@ function(config)
       (import 'time.libsonnet')(on),
       (import 'exporter.libsonnet')(on),
     ]
-    if !tab.empty
+    if tab != null && !tab.empty
   ];
 
   local panelNames = std.flattenArrays([std.objectFields(tab.elements) for tab in tabs]);

contrib/mixin/tests/dashboard.test.jsonnet

@@ -3,8 +3,8 @@
 // empty. Run with jsonnet -J vendor tests/dashboard.test.jsonnet.
 local mixin = import '../mixin.libsonnet';
 
-local render(collectors) =
-  (mixin { _config+:: { collectors: collectors(super.collectors) } }).grafanaDashboards['windows-exporter.json'];
+local render(collectors, config={}) =
+  (mixin { _config+:: { collectors: collectors(super.collectors) } + config }).grafanaDashboards['windows-exporter.json'];
 local all(value) = function(collectors) { [name]: value for name in std.objectFields(collectors) };
 
 local placed(layout) =
@@ -36,6 +36,8 @@ local results = {
   storageSpacesOnly: summary(render(only({ storage_spaces: true }))).Disk,
   // A collectors object given without +: enables only the listed collectors.
   replaced: summary(render(function(_) { os: true, cpu: true })),
+  // Only collector tabs, for a compact dashboard.
+  collectorTabsOnly: summary(render(function(_) { os: true, cpu: true }, { enableFleetTab: false, enableOverviewTab: false })),
 };
 
 local expect(name, want) =
@@ -64,5 +66,9 @@ assert expect('replaced', {
   Fleet: ['Summary', 'Hosts', 'Utilization'],
   Overview: ['Summary', 'CPU and memory'],
 });
+assert expect('collectorTabsOnly', {
+  CPU: ['Summary', 'Utilization', 'System calls and frequency'],
+  Exporter: exporter,
+});
 
 results

dashboard/windows-exporter-dashboard.json

@@ -1031,7 +1031,7 @@
                             "transformations": []
                         }
                     },
-                    "description": "Steady growth of goroutines points to a goroutine leak. Goroutines that stay \"not in Go\" sit in a system call, for example a collector waiting on WMI or PDH. The states need an exporter build with the Go scheduler metrics; the total line works with every build.",
+                    "description": "Steady growth of goroutines points to a goroutine leak. Goroutines that stay \"not in Go\" sit in a system call, for example a collector waiting on WMI or PDH. The states need an exporter build with the Go scheduler metrics; the total line works with every build. Since 0.32, \"not in Go\" keeps growing even without a leak: a Go runtime bug (golang/go#82136) counts each WMI callback from a Windows thread once and never subtracts it. Use the total line to spot a leak instead.",
                     "id": 107,
                     "links": [],
                     "title": "Goroutines by state",