From e80bc4b0621074a395741d1ccb2955c811f1dd7a Mon Sep 17 00:00:00 2001
From: Eric Eastwood <erice@element.io>
Date: Thu, 5 Jun 2025 15:30:28 -0500
Subject: [PATCH] Distinguish all vs local events being persisted in the "Event
 Send Time Quantiles" graph (#18510)

(Applies to the Grafana graphs)

As discovered by @devonh, we use `synapse_storage_events_persisted_events_total` (which tracks *all* persisted events) for the "Events" rate in the "Event Send Time Quantiles" graph. This is pretty misleading as I would expect it to be the rate of events being sent given the graph title, "Event Send Time Quantiles".

Since the event persistence queues are shared for local and remote events from federation and will block local events being sent, I think it does still make sense to have the event persist rate. I've updated the graph to include the rate of "Local events being persisted" and the rate of "All events being persisted". I think this properly disambiguates and clarifies what the graph is trying to show.
---
 changelog.d/18510.misc       |  1 +
 contrib/grafana/synapse.json | 96 ++++++++++++++++++++++++------------
 2 files changed, 66 insertions(+), 31 deletions(-)
 create mode 100644 changelog.d/18510.misc

diff --git a/changelog.d/18510.misc b/changelog.d/18510.misc
new file mode 100644
index 0000000000..71a3549d31
--- /dev/null
+++ b/changelog.d/18510.misc
@@ -0,0 +1 @@
+Distinguish all vs local events being persisted in the "Event Send Time Quantiles" graph (Grafana).
diff --git a/contrib/grafana/synapse.json b/contrib/grafana/synapse.json
index 30d6d87500..62b58a199d 100644
--- a/contrib/grafana/synapse.json
+++ b/contrib/grafana/synapse.json
@@ -220,29 +220,24 @@
       "yBucketBound": "auto"
     },
     {
-      "aliasColors": {},
-      "bars": false,
-      "dashLength": 10,
-      "dashes": false,
       "datasource": {
-        "uid": "${DS_PROMETHEUS}"
+        "uid": "${DS_PROMETHEUS}",
+        "type": "prometheus"
       },
-      "description": "",
+      "aliasColors": {},
+      "dashLength": 10,
       "fieldConfig": {
         "defaults": {
           "links": []
         },
         "overrides": []
       },
-      "fill": 0,
-      "fillGradient": 0,
       "gridPos": {
         "h": 9,
         "w": 12,
         "x": 12,
         "y": 1
       },
-      "hiddenSeries": false,
       "id": 152,
       "legend": {
         "avg": false,
@@ -255,71 +250,81 @@
         "values": false
       },
       "lines": true,
-      "linewidth": 0,
-      "links": [],
       "nullPointMode": "connected",
       "options": {
         "alertThreshold": true
       },
       "paceLength": 10,
-      "percentage": false,
-      "pluginVersion": "9.2.2",
+      "pluginVersion": "10.4.3",
       "pointradius": 5,
-      "points": false,
       "renderer": "flot",
       "seriesOverrides": [
         {
           "alias": "Avg",
           "fill": 0,
-          "linewidth": 3
+          "linewidth": 3,
+          "$$hashKey": "object:48"
         },
         {
           "alias": "99%",
           "color": "#C4162A",
-          "fillBelowTo": "90%"
+          "fillBelowTo": "90%",
+          "$$hashKey": "object:49"
         },
         {
           "alias": "90%",
           "color": "#FF7383",
-          "fillBelowTo": "75%"
+          "fillBelowTo": "75%",
+          "$$hashKey": "object:50"
         },
         {
           "alias": "75%",
           "color": "#FFEE52",
-          "fillBelowTo": "50%"
+          "fillBelowTo": "50%",
+          "$$hashKey": "object:51"
         },
         {
           "alias": "50%",
           "color": "#73BF69",
-          "fillBelowTo": "25%"
+          "fillBelowTo": "25%",
+          "$$hashKey": "object:52"
         },
         {
           "alias": "25%",
           "color": "#1F60C4",
-          "fillBelowTo": "5%"
+          "fillBelowTo": "5%",
+          "$$hashKey": "object:53"
         },
         {
           "alias": "5%",
-          "lines": false
+          "lines": false,
+          "$$hashKey": "object:54"
         },
         {
           "alias": "Average",
           "color": "rgb(255, 255, 255)",
           "lines": true,
-          "linewidth": 3
+          "linewidth": 3,
+          "$$hashKey": "object:55"
         },
         {
-          "alias": "Events",
+          "alias": "Local events being persisted",
+          "color": "#96d98D",
+          "points": true,
+          "yaxis": 2,
+          "zindex": -3,
+          "$$hashKey": "object:56"
+        },
+        {
+          "$$hashKey": "object:329",
           "color": "#B877D9",
-          "hideTooltip": true,
+          "alias": "All events being persisted",
           "points": true,
           "yaxis": 2,
           "zindex": -3
         }
       ],
       "spaceLength": 10,
-      "stack": false,
-      "steppedLine": false,
       "targets": [
         {
           "datasource": {
@@ -384,7 +389,20 @@
           },
           "expr": "sum(rate(synapse_http_server_response_time_seconds_sum{servlet='RoomSendEventRestServlet',index=~\"$index\",instance=\"$instance\",code=~\"2..\"}[$bucket_size])) / sum(rate(synapse_http_server_response_time_seconds_count{servlet='RoomSendEventRestServlet',index=~\"$index\",instance=\"$instance\",code=~\"2..\"}[$bucket_size]))",
           "legendFormat": "Average",
-          "refId": "H"
+          "refId": "H",
+          "editorMode": "code",
+          "range": true
+        },
+        {
+          "datasource": {
+            "uid": "${DS_PROMETHEUS}"
+          },
+          "expr": "sum(rate(synapse_http_server_response_time_seconds_count{servlet='RoomSendEventRestServlet',index=~\"$index\",instance=\"$instance\",code=~\"2..\"}[$bucket_size]))",
+          "hide": false,
+          "instant": false,
+          "legendFormat": "Local events being persisted",
+          "refId": "E",
+          "editorMode": "code"
         },
         {
           "datasource": {
@@ -393,8 +411,9 @@
           "expr": "sum(rate(synapse_storage_events_persisted_events_total{instance=\"$instance\"}[$bucket_size]))",
           "hide": false,
           "instant": false,
-          "legendFormat": "Events",
-          "refId": "E"
+          "legendFormat": "All events being persisted",
+          "refId": "I",
+          "editorMode": "code"
         }
       ],
       "thresholds": [
@@ -428,7 +447,9 @@
       "xaxis": {
         "mode": "time",
         "show": true,
-        "values": []
+        "values": [],
+        "name": null,
+        "buckets": null
       },
       "yaxes": [
         {
@@ -450,7 +471,20 @@
       ],
       "yaxis": {
         "align": false
-      }
+      },
+      "bars": false,
+      "dashes": false,
+      "description": "",
+      "fill": 0,
+      "fillGradient": 0,
+      "hiddenSeries": false,
+      "linewidth": 0,
+      "percentage": false,
+      "points": false,
+      "stack": false,
+      "steppedLine": false,
+      "timeFrom": null,
+      "timeShift": null
     },
     {
       "aliasColors": {},