add a dashboard for log deletion requests in loki (#3794)

production/loki-mixin/dashboards.libsonnet

@@ -6,4 +6,5 @@
 (import 'dashboards/loki-reads.libsonnet') +
 (import 'dashboards/loki-writes.libsonnet') +
 (import 'dashboards/loki-writes-resources.libsonnet') +
-(import 'dashboards/loki-reads-resources.libsonnet')
+(import 'dashboards/loki-reads-resources.libsonnet') +
+(import 'dashboards/loki-deletion.libsonnet')

production/loki-mixin/dashboards/loki-deletion.libsonnet

@@ -0,0 +1,43 @@
+local g = import 'grafana-builder/grafana.libsonnet';
+local utils = import 'mixin-utils/utils.libsonnet';
+
+(import 'dashboard-utils.libsonnet') {
+  grafanaDashboards+::
+    {
+      'loki-deletion.json':
+        ($.dashboard('Loki / Deletion', uid='retention'))
+        .addClusterSelectorTemplates(false)
+        .addRow(
+          ($.row('Headlines') +
+           {
+             height: '100px',
+             showTitle: false,
+           })
+          .addPanel(
+            $.panel('Number of Pending Requests') +
+            $.statPanel('sum(loki_compactor_pending_delete_requests_count{%s})' % $.namespaceMatcher(), format='none')
+          )
+          .addPanel(
+            $.panel('Oldest Pending Request Age') +
+            $.statPanel('max(loki_compactor_oldest_pending_delete_request_age_seconds{%s})' % $.namespaceMatcher(), format='dtdurations')
+          )
+        )
+        .addRow(
+          g.row('Churn')
+          .addPanel(
+            g.panel('Delete Requests Received / Day') +
+            g.queryPanel('sum(increase(loki_compactor_delete_requests_received_total{%s}[1d]))' % $.namespaceMatcher(), 'received'),
+          )
+          .addPanel(
+            g.panel('Delete Requests Processed / Day') +
+            g.queryPanel('sum(increase(loki_compactor_delete_requests_processed_total{%s}[1d]))' % $.namespaceMatcher(), 'processed'),
+          )
+        ).addRow(
+          g.row('Failures')
+          .addPanel(
+            g.panel('Failures in Loading Delete Requests / Hour') +
+            g.queryPanel('sum(increase(loki_compactor_load_pending_requests_attempts_total{status="fail", %s}[1h]))' % $.namespaceMatcher(), 'failures'),
+          )
+        ),
+    },
+}