From 650e8a12eff9781258f7d48ecffbdf327098888a Mon Sep 17 00:00:00 2001
From: Sheogorath <sheogorath@shivering-isles.com>
Date: Sun, 1 May 2022 03:12:35 +0200
Subject: [PATCH] feat(matrix): Add dashboard to further analyse the synapse
mystery
After digging a bit deeper into the data, it's clear that there is a
correlation between large volume of DNS requests and the `GET` requests
to the `_matrix` route.
When these slow down, the DNS requests suddenly also disappear. It's
noteworthy, that `PUT` requests (means incoming Events), remain
unchanged.
The potential releation became apparent, when on 2022-04-30 during the
evening hours, there is a 21:30 to 01:55 CEST time window where this
correlation becoming apparant.
The `GET` request can be more drilled down using the Synapse Dashboard
to be `SyncRestServlet` requests. These requests are client requests, to
keep the client state up-to-date and active and explains the lack of
requests for a few hours, when Element Desktop was shut down.
This needs some further drill down into Synapse's internals to figure
out exactly what causes these mass request, but `presence` is a good
contender.
References:
https://github.com/matrix-org/synapse/blob/0922462fc7df951e88c8ec0fb35e53e3cd801b76/synapse/rest/client/sync.py#L52
https://github.com/matrix-org/synapse/tree/8d156ec0ba17d848581f18aa40ebfd76dda763d4/contrib/grafana
---
.../matrix/dashboards/mystery-board.json | 249 ++++++++++++++++++
apps/k8s01/matrix/kustomization.yaml | 7 +
2 files changed, 256 insertions(+)
create mode 100644 apps/k8s01/matrix/dashboards/mystery-board.json
diff --git a/apps/k8s01/matrix/dashboards/mystery-board.json b/apps/k8s01/matrix/dashboards/mystery-board.json
new file mode 100644
index 000000000..fafccf412
--- /dev/null
+++ b/apps/k8s01/matrix/dashboards/mystery-board.json
@@ -0,0 +1,249 @@
+{
+ "__inputs": [
+ {
+ "name": "DS_PROMETHEUS",
+ "label": "Prometheus",
+ "description": "",
+ "type": "datasource",
+ "pluginId": "prometheus",
+ "pluginName": "Prometheus"
+ }
+ ],
+ "__elements": [],
+ "__requires": [
+ {
+ "type": "grafana",
+ "id": "grafana",
+ "name": "Grafana",
+ "version": "8.4.6"
+ },
+ {
+ "type": "datasource",
+ "id": "prometheus",
+ "name": "Prometheus",
+ "version": "1.0.0"
+ },
+ {
+ "type": "panel",
+ "id": "timeseries",
+ "name": "Time series",
+ "version": ""
+ }
+ ],
+ "annotations": {
+ "list": [
+ {
+ "builtIn": 1,
+ "datasource": "-- Grafana --",
+ "enable": true,
+ "hide": true,
+ "iconColor": "rgba(0, 211, 255, 1)",
+ "name": "Annotations & Alerts",
+ "target": {
+ "limit": 100,
+ "matchAny": false,
+ "tags": [],
+ "type": "dashboard"
+ },
+ "type": "dashboard"
+ }
+ ]
+ },
+ "editable": true,
+ "fiscalYearStartMonth": 0,
+ "graphTooltip": 0,
+ "id": null,
+ "links": [],
+ "liveNow": false,
+ "panels": [
+ {
+ "fieldConfig": {
+ "defaults": {
+ "color": {
+ "mode": "palette-classic"
+ },
+ "custom": {
+ "axisLabel": "",
+ "axisPlacement": "auto",
+ "barAlignment": 0,
+ "drawStyle": "line",
+ "fillOpacity": 0,
+ "gradientMode": "none",
+ "hideFrom": {
+ "legend": false,
+ "tooltip": false,
+ "viz": false
+ },
+ "lineInterpolation": "linear",
+ "lineWidth": 1,
+ "pointSize": 5,
+ "scaleDistribution": {
+ "type": "linear"
+ },
+ "showPoints": "auto",
+ "spanNulls": false,
+ "stacking": {
+ "group": "A",
+ "mode": "none"
+ },
+ "thresholdsStyle": {
+ "mode": "off"
+ }
+ },
+ "mappings": [],
+ "thresholds": {
+ "mode": "absolute",
+ "steps": [
+ {
+ "color": "green",
+ "value": null
+ },
+ {
+ "color": "red",
+ "value": 80
+ }
+ ]
+ }
+ },
+ "overrides": []
+ },
+ "gridPos": {
+ "h": 17,
+ "w": 24,
+ "x": 0,
+ "y": 0
+ },
+ "id": 4,
+ "options": {
+ "legend": {
+ "calcs": [],
+ "displayMode": "list",
+ "placement": "bottom"
+ },
+ "tooltip": {
+ "mode": "single",
+ "sort": "none"
+ }
+ },
+ "targets": [
+ {
+ "datasource": {
+ "type": "prometheus",
+ "uid": "${DS_PROMETHEUS}"
+ },
+ "exemplar": true,
+ "expr": "rate(nginx_ingress_controller_requests{exported_namespace=\"matrix\"}[5m])",
+ "interval": "",
+ "legendFormat": "",
+ "refId": "A"
+ }
+ ],
+ "title": "Panel Title",
+ "type": "timeseries"
+ },
+ {
+ "fieldConfig": {
+ "defaults": {
+ "color": {
+ "mode": "palette-classic"
+ },
+ "custom": {
+ "axisLabel": "",
+ "axisPlacement": "auto",
+ "barAlignment": 0,
+ "drawStyle": "line",
+ "fillOpacity": 0,
+ "gradientMode": "none",
+ "hideFrom": {
+ "legend": false,
+ "tooltip": false,
+ "viz": false
+ },
+ "lineInterpolation": "linear",
+ "lineWidth": 1,
+ "pointSize": 5,
+ "scaleDistribution": {
+ "type": "linear"
+ },
+ "showPoints": "auto",
+ "spanNulls": false,
+ "stacking": {
+ "group": "A",
+ "mode": "none"
+ },
+ "thresholdsStyle": {
+ "mode": "off"
+ }
+ },
+ "mappings": [],
+ "thresholds": {
+ "mode": "absolute",
+ "steps": [
+ {
+ "color": "green",
+ "value": null
+ },
+ {
+ "color": "red",
+ "value": 80
+ }
+ ]
+ }
+ },
+ "overrides": []
+ },
+ "gridPos": {
+ "h": 16,
+ "w": 24,
+ "x": 0,
+ "y": 17
+ },
+ "id": 2,
+ "options": {
+ "legend": {
+ "calcs": [],
+ "displayMode": "list",
+ "placement": "bottom"
+ },
+ "tooltip": {
+ "mode": "single",
+ "sort": "none"
+ }
+ },
+ "targets": [
+ {
+ "datasource": {
+ "type": "prometheus",
+ "uid": "${DS_PROMETHEUS}"
+ },
+ "exemplar": true,
+ "expr": "sum(rate(coredns_dns_request_count_total{job=\"coredns\",instance=~\".*\"}[5m])) by (proto) or\nsum(rate(coredns_dns_requests_total{job=\"coredns\",instance=~\".*\"}[5m])) by (proto)",
+ "interval": "",
+ "legendFormat": "",
+ "refId": "A"
+ }
+ ],
+ "title": "Panel Title",
+ "type": "timeseries"
+ }
+ ],
+ "schemaVersion": 35,
+ "style": "dark",
+ "tags": [
+ "synapse",
+ "coredns"
+ ],
+ "templating": {
+ "list": []
+ },
+ "time": {
+ "from": "now-2d",
+ "to": "now"
+ },
+ "timepicker": {},
+ "timezone": "",
+ "title": "Synapse / DNS Mystery Board",
+ "uid": "uouldz_7z",
+ "version": 2,
+ "weekStart": ""
+}
diff --git a/apps/k8s01/matrix/kustomization.yaml b/apps/k8s01/matrix/kustomization.yaml
index 79d891d96..eae9ac364 100644
--- a/apps/k8s01/matrix/kustomization.yaml
+++ b/apps/k8s01/matrix/kustomization.yaml
@@ -9,3 +9,10 @@ resources:
patchesStrategicMerge:
- database-override.yaml
- matrix-synapse-values.yaml
+configMapGenerator:
+ - name: synapse-mystery
+ files:
+ - ./dashboards/mystery-dashboard.json
+ options:
+ labels:
+ grafana_dashboard: matrix
--
GitLab