diff --git a/.circleci/config.yml b/.circleci/config.yml
index e4aac72a0..a0a9840ad 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -124,6 +124,10 @@ jobs:
     - checkout
     - attach_workspace:
         at: *working_directory
+    - restore_cache:
+        keys:
+          - temboard-{{ .Branch }}
+          - temboard-master
     - run:
         name: Build Agent & UI
         command: |
@@ -139,6 +143,10 @@ jobs:
         - agent/dist/*.whl
         - ui/dist/*.tar.gz
         - ui/dist/*.whl
+        - ui/build/bin/prometheus
+    - save_cache:
+        key: temboard-{{ .Branch }}
+        paths: ["dev/downloads/"]
 
   lint-python:
     docker: [image: python:3.9]
@@ -265,8 +273,8 @@ jobs:
     - persist_to_workspace:
         root: .
         paths:
-        - agent/dist/*.noarch.rpm
-        - ui/dist/*.noarch.rpm
+        - agent/dist/temboard-agent-*.noarch.rpm
+        - ui/dist/temboard-*.rpm
 
   deb:
     parameters:
diff --git a/.config/temboard.conf b/.config/temboard.conf
index 74de0c6c8..56dee556a 100644
--- a/.config/temboard.conf
+++ b/.config/temboard.conf
@@ -49,7 +49,7 @@ method = stderr
 level = DEBUG
 
 [monitoring]
-prometheus = dev/bin/prometheus
+prometheus = ui/build/bin/prometheus
 
 [notifications]
 # SMTP host
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 17ace3efa..81756998c 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -471,30 +471,6 @@ and if not found, tries to download wheel from PyPI.
 Use top level `make dist` to generate wheels.
 
 
-## Testing with Grafana
-
-temBoard exposes /metrics in OpenMetric format. Development environment
-includes Prometheus and Grafana preconfigured with authenticated access and
-file-based service discovery. You only need a couple of steps to view temBoard
-metrics in Grafana.
-
-- Start development temBoard UI and at lease one of agent0 or agent1.
-- Generate Prometheus targets using `make prom-targets`.
-- Go to [development Grafana import page](http://localhost:3000/dashboard/import).
-- Import Dashboard ID [1860](https://grafana.com/grafana/dashboards/1860)
-  (*Node Exporter Full*) or [9628](https://grafana.com/grafana/dashboards/1860)
-  (*PostgreSQL Database*).
-- Now wait a few minutes that Prometheus scrapes data. Scrape interval is 1
-  minute.
-
-temBoard exposes only a subset of metrics from node\_exporter and
-postgres\_exporter, plus a set of custom metrics prefixed with `x`, e.g.
-`xpg_wal_files_bytes_total`. Thus a lot of panel will show *N/A*.
-
-Prometheus also watch `dev/prometheus/targets/custom.yaml` files for hand
-written targets.
-
-
 ## Investigate logs with lnav
 
 [lnav] is an awesome tool to browse and analyze log files.
diff --git a/Makefile b/Makefile
index e4e6212c2..1b0f99bda 100644
--- a/Makefile
+++ b/Makefile
@@ -15,7 +15,7 @@ develop-%:: .env
 	@dev/bin/checkdocker $(DOCKER_MAX_VERSION)
 	git config blame.ignoreRevsFile .git-blame-ignore-revs
 	if [ -d ~/.config/lnav/formats ] ; then ln -fsTv $$PWD/dev/lnav/formats ~/.config/lnav/formats/temboard ; fi
-	$(MAKE) -j 2 install-$* dev/bin/prometheus
+	$(MAKE) -j 2 install-$* ui/build/bin/prometheus ui/build/bin/promtool
 	mkdir -p dev/temboard
 	cd ui/; npm install-clean
 	cd ui/; npm run build
@@ -56,20 +56,21 @@ install-%: venv-%
 	dev/venv-py$*/bin/temboard-agent --version  # smoke test
 
 # LTS
-PROMETHEUS_VERSION=2.45.1
+PROMETHEUS_VERSION=2.53.0
 dev/downloads/prometheus-%.linux-amd64.tar.gz:
 	mkdir -p $(dir $@)
 	curl --fail --silent -L "https://github.com/prometheus/prometheus/releases/download/v$*/$(notdir $@)" --output $@
 
-dev/bin/prometheus dev/bin/promtool: dev/downloads/prometheus-$(PROMETHEUS_VERSION).linux-amd64.tar.gz
+ui/build/bin/prometheus ui/build/bin/promtool: dev/downloads/prometheus-$(PROMETHEUS_VERSION).linux-amd64.tar.gz
+	mkdir -p $(dir $@)
 	tar --extract --file "$<" --directory "$(dir $@)" --strip-component=1 --touch "prometheus-$(PROMETHEUS_VERSION).linux-amd64/$(notdir $@)"
 	"$@" --version  # Smoketest
 
 clean:  #: Trash venv and containers.
 	docker compose down --volumes --remove-orphans
 	docker rmi --force dalibo/temboard-agent:dev
-	rm -rf dev/venv-py* .venv-py* dev/build/ dev/prometheus/targets/temboard-dev.yaml
-	rm -vf dev/bin/prometheus dev/bin/promtool
+	rm -rf dev/venv-py* .venv-py* dev/build/
+	rm -vf ui/build/bin/prometheus ui/build/bin/promtool
 	rm -rf agent/build/ .env agent/.coverage
 	rm -rvf ui/build/ ui/.coverage
 	$(MAKE) clean-static
@@ -127,10 +128,6 @@ tests:  #: Execute all tests.
 clean-tests:  #: Clean tests runtime files
 	rm -rf tests/downloads/ tests/logs/ tests/screenshots/
 
-prom-targets: dev/prometheus/targets/temboard-dev.yaml  #: Generate Prometheus dev targets.
-dev/prometheus/targets/temboard-dev.yaml: dev/bin/mktargets .env
-	$^ > $@
-
 VERSION=$(shell cd ui; python3 setup.py --version)
 BRANCH?=master
 # When stable branch v8 is created, use this:
@@ -162,7 +159,7 @@ release:  #: Tag and push a new git release.
 release-notes:  #: Extract changes for current release
 	FINAL_VERSION="$(shell echo $(VERSION) | grep -Po '([^a-z]{3,})')" ; sed -En "/Unreleased/d;/^#+ $$FINAL_VERSION/,/^#/p" CHANGELOG.md  | sed '1d;$$d'
 
-dist:  #: Build sources and wheels.
+dist:  ui/build/bin/prometheus  #: Build sources and wheels.
 	cd agent/; python3 setup.py sdist bdist_wheel
 	test -f ui/temboardui/static/dist/.vite/manifest.json
 	cd ui/; python3 setup.py sdist bdist_wheel --universal
diff --git a/agent/temboardagent/web/service.py b/agent/temboardagent/web/service.py
index b0ccbf9ef..ab69c458a 100644
--- a/agent/temboardagent/web/service.py
+++ b/agent/temboardagent/web/service.py
@@ -22,7 +22,7 @@ def __str__(self):
         return self.name
 
     # for services.run
-    def setup(self):
+    def setup(self, *_, **__):
         ServerHandler.server_software = "temBoard-agent/%s" % __version__
 
         try:
diff --git a/dev/bin/mktargets b/dev/bin/mktargets
deleted file mode 100755
index fa7b0908e..000000000
--- a/dev/bin/mktargets
+++ /dev/null
@@ -1,24 +0,0 @@
-#!/bin/bash -eu
-
-# shellcheck source=/dev/null
-. .env
-
-target="${TEMBOARD_UI_URL#https://}"
-
-cat <<-EOF
-- targets:
-  - $target
-  labels:
-    __metrics_path__: /proxy/0.0.0.0/2345/monitoring/metrics
-    instance: "postgres0.dev:5432"
-    # For PostgreSQL Database dashboard #9628
-    kubernetes_namespace: nok8s
-    release: norelease
-- targets:
-  - $target
-  labels:
-    __metrics_path__: /proxy/0.0.0.0/2346/monitoring/metrics
-    instance: "postgres1.dev:5432"
-    kubernetes_namespace: nok8s
-    release: norelease
-EOF
diff --git a/dev/grafana/rootfs/etc/grafana/provisioning/dashboards/perf.yaml b/dev/grafana/rootfs/etc/grafana/provisioning/dashboards/perf.yaml
index 7bf753ee0..3abb04797 100644
--- a/dev/grafana/rootfs/etc/grafana/provisioning/dashboards/perf.yaml
+++ b/dev/grafana/rootfs/etc/grafana/provisioning/dashboards/perf.yaml
@@ -7,15 +7,3 @@ providers:
   allowUiUpdates: true
   options:
     path: /usr/share/temboard/perf.json
-- name: "Postgres from temBoard agent"
-  type: file
-  folder: ''
-  allowUiUpdates: true
-  options:
-    path: /usr/share/temboard/postgres.json
-- name: "temBoard Prometheus"
-  type: file
-  folder: ''
-  allowUiUpdates: true
-  options:
-    path: /usr/share/temboard/temboard-prometheus.json
diff --git a/dev/grafana/rootfs/usr/share/temboard/postgres.json b/dev/grafana/rootfs/usr/share/temboard/postgres.json
deleted file mode 100644
index 3bbabc85e..000000000
--- a/dev/grafana/rootfs/usr/share/temboard/postgres.json
+++ /dev/null
@@ -1,201 +0,0 @@
-{
-  "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": 2,
-  "iteration": 1643970369705,
-  "links": [],
-  "liveNow": false,
-  "panels": [
-    {
-      "fieldConfig": {
-        "defaults": {
-          "color": {
-            "mode": "palette-classic"
-          },
-          "custom": {
-            "axisLabel": "",
-            "axisPlacement": "auto",
-            "barAlignment": 0,
-            "drawStyle": "line",
-            "fillOpacity": 50,
-            "gradientMode": "none",
-            "hideFrom": {
-              "legend": false,
-              "tooltip": false,
-              "viz": false
-            },
-            "lineInterpolation": "linear",
-            "lineWidth": 1,
-            "pointSize": 5,
-            "scaleDistribution": {
-              "type": "linear"
-            },
-            "showPoints": "never",
-            "spanNulls": false,
-            "stacking": {
-              "group": "A",
-              "mode": "normal"
-            },
-            "thresholdsStyle": {
-              "mode": "off"
-            }
-          },
-          "mappings": [],
-          "thresholds": {
-            "mode": "absolute",
-            "steps": [
-              {
-                "color": "green",
-                "value": null
-              },
-              {
-                "color": "red",
-                "value": 80
-              }
-            ]
-          }
-        },
-        "overrides": []
-      },
-      "gridPos": {
-        "h": 7,
-        "w": 24,
-        "x": 0,
-        "y": 0
-      },
-      "id": 4,
-      "options": {
-        "legend": {
-          "calcs": [],
-          "displayMode": "list",
-          "placement": "bottom"
-        },
-        "tooltip": {
-          "mode": "multi"
-        }
-      },
-      "targets": [
-        {
-          "datasource": {
-            "type": "prometheus",
-            "uid": "01lWBBhnk"
-          },
-          "exemplar": true,
-          "expr": "sum(rate(xacts_n_commit{logfile=\"$logfile\"}[5m]))",
-          "interval": "",
-          "legendFormat": "commit",
-          "refId": "A"
-        },
-        {
-          "datasource": {
-            "type": "prometheus",
-            "uid": "01lWBBhnk"
-          },
-          "exemplar": true,
-          "expr": "sum(rate(xacts_n_rollback{logfile=\"$logfile\"}[5m]))",
-          "hide": false,
-          "interval": "",
-          "legendFormat": "rollback",
-          "refId": "B"
-        }
-      ],
-      "title": "TPS",
-      "type": "timeseries"
-    },
-    {
-      "datasource": {
-        "type": "loki",
-        "uid": "j1tzJKb7k"
-      },
-      "gridPos": {
-        "h": 13,
-        "w": 24,
-        "x": 0,
-        "y": 7
-      },
-      "id": 2,
-      "options": {
-        "dedupStrategy": "none",
-        "enableLogDetails": true,
-        "prettifyLogMessage": false,
-        "showCommonLabels": false,
-        "showLabels": false,
-        "showTime": false,
-        "sortOrder": "Ascending",
-        "wrapLogMessage": false
-      },
-      "targets": [
-        {
-          "datasource": {
-            "type": "loki",
-            "uid": "j1tzJKb7k"
-          },
-          "expr": "{logfile=~\"$logfile\"}",
-          "refId": "A"
-        }
-      ],
-      "title": "Messages",
-      "type": "logs"
-    }
-  ],
-  "refresh": false,
-  "schemaVersion": 33,
-  "style": "dark",
-  "tags": [],
-  "templating": {
-    "list": [
-      {
-        "current": {
-          "selected": false,
-          "text": ".+",
-          "value": ".+"
-        },
-        "definition": "label_values(logfile)",
-        "hide": 0,
-        "includeAll": false,
-        "multi": false,
-        "name": "logfile",
-        "options": [],
-        "query": {
-          "query": "label_values(logfile)",
-          "refId": "StandardVariableQuery"
-        },
-        "refresh": 1,
-        "regex": "",
-        "skipUrlSync": false,
-        "sort": 1,
-        "type": "query"
-      }
-    ]
-  },
-  "time": {
-    "from": "now-3h",
-    "to": "now"
-  },
-  "timepicker": {},
-  "timezone": "",
-  "title": "Postgres",
-  "uid": "gQ7FEi-7z",
-  "version": 3,
-  "weekStart": ""
-}
diff --git a/dev/grafana/rootfs/usr/share/temboard/temboard-prometheus.json b/dev/grafana/rootfs/usr/share/temboard/temboard-prometheus.json
deleted file mode 100644
index 7ad8c801d..000000000
--- a/dev/grafana/rootfs/usr/share/temboard/temboard-prometheus.json
+++ /dev/null
@@ -1,137 +0,0 @@
-{
-  "annotations": {
-    "list": [
-      {
-        "builtIn": 1,
-        "datasource": {
-          "type": "grafana",
-          "uid": "-- 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": 3,
-  "links": [],
-  "liveNow": false,
-  "panels": [
-    {
-      "datasource": {
-        "type": "prometheus",
-        "uid": "Kme6NfMSz"
-      },
-      "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": 9,
-        "w": 12,
-        "x": 0,
-        "y": 0
-      },
-      "id": 2,
-      "options": {
-        "legend": {
-          "calcs": [],
-          "displayMode": "list",
-          "placement": "bottom"
-        },
-        "tooltip": {
-          "mode": "single",
-          "sort": "none"
-        }
-      },
-      "targets": [
-        {
-          "datasource": {
-            "type": "prometheus",
-            "uid": "Kme6NfMSz"
-          },
-          "editorMode": "builder",
-          "expr": "node_load1",
-          "legendFormat": "__auto",
-          "range": true,
-          "refId": "A"
-        }
-      ],
-      "title": "Panel Title",
-      "type": "timeseries"
-    }
-  ],
-  "schemaVersion": 36,
-  "style": "dark",
-  "tags": [],
-  "templating": {
-    "list": []
-  },
-  "time": {
-    "from": "now-1h",
-    "to": "now"
-  },
-  "timepicker": {},
-  "timezone": "",
-  "title": "temBoard Prometheus",
-  "uid": "aC9VOfMSk",
-  "version": 1,
-  "weekStart": ""
-}
diff --git a/docker-compose.yml b/docker-compose.yml
index febc6d80b..0f629ec7f 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -214,7 +214,6 @@ services:
     volumes:
     - ./dev/prometheus/prometheus.yml:/etc/prometheus/prometheus.yml
     - ./dev/prometheus/import:/import
-    - ./dev/prometheus/targets:/targets
     ports:
     - 9090:9090
     command:
diff --git a/tests/test_00_setup_ui.py b/tests/test_00_setup_ui.py
index 0d05027e1..d436eed11 100644
--- a/tests/test_00_setup_ui.py
+++ b/tests/test_00_setup_ui.py
@@ -119,7 +119,7 @@ def test_proctitle(ui):
             continue
 
         assert cmdline.startswith("temboard: "), cmdline
-        assert ": worker" in cmdline or ": scheduler" in cmdline
+        assert ": web" not in cmdline
 
 
 def test_autossl(ui):
diff --git a/tests/test_10_setup_agent.py b/tests/test_10_setup_agent.py
index 7f0b70055..c580d980a 100644
--- a/tests/test_10_setup_agent.py
+++ b/tests/test_10_setup_agent.py
@@ -68,8 +68,7 @@ def test_proctitle(agent):
                     cmdline = fo.read()
 
                 assert cmdline.startswith("temboard-agent: temboard-tests: ")
-
-                assert ": worker" in cmdline or ": scheduler" in cmdline
+                assert ": web" not in cmdline
 
 
 def test_discover_http(agent, agent_env, pg_version):
diff --git a/ui/packaging/deb/mkdeb.sh b/ui/packaging/deb/mkdeb.sh
index dcd1061ac..296b1968c 100755
--- a/ui/packaging/deb/mkdeb.sh
+++ b/ui/packaging/deb/mkdeb.sh
@@ -61,6 +61,7 @@ mv "$DESTDIR/usr/local/lib"/*/dist-packages  "$DESTDIR/usr/lib/temboard"
 mv "$DESTDIR/usr/local/lib/systemd"  "$DESTDIR/usr/lib"
 # Move binaries out of FHS.
 mv "$DESTDIR/usr/local/bin" "$DESTDIR/usr/lib/temboard/"
+cp build/bin/prometheus "$DESTDIR/usr/lib/temboard/"
 rm -rf "${DESTDIR:?}/usr/local"
 
 # Create FHS wrapper.
@@ -101,6 +102,7 @@ apt-get install --yes --no-install-recommends "./$deb"
 	cd /
 	temboard --version
 	test -f /usr/lib/temboard/temboardui/static/dist/.vite/manifest.json
+	test -x /usr/lib/temboard/prometheus
 	test -x /usr/share/temboard/auto_configure.sh
 	test -f /usr/lib/systemd/system/temboard.service
 )
diff --git a/ui/packaging/rpm/build.sh b/ui/packaging/rpm/build.sh
index 846909e38..fe342c507 100755
--- a/ui/packaging/rpm/build.sh
+++ b/ui/packaging/rpm/build.sh
@@ -10,4 +10,8 @@ test -f "dist/temboard-$VERSION.tar.gz"
 cp --preserve --force packaging/rpm/temboard.spec /tmp/temboard.spec
 sed -i "/^Version:/s/GENERATED/$VERSION/" /tmp/temboard.spec
 export BUILDDIR="$PWD/dist/" SMOKETEST=1
-exec rpmbuild.sh /tmp/temboard.spec "dist/temboard-$VERSION.tar.gz"
+# Globally disable debug package generation.
+cat >>/etc/rpm/macros.temboard <<EOF
+%debug_package %{nil}
+EOF
+exec rpmbuild.sh /tmp/temboard.spec "dist/temboard-$VERSION.tar.gz" build/bin/prometheus
diff --git a/ui/packaging/rpm/temboard.spec b/ui/packaging/rpm/temboard.spec
index 6dcb5790f..8730a5070 100644
--- a/ui/packaging/rpm/temboard.spec
+++ b/ui/packaging/rpm/temboard.spec
@@ -2,6 +2,8 @@
 %global confdir %{_sysconfdir}/%{pkgname}
 
 %global __python /usr/bin/python3
+# Workaround for embedding official Prometheus binary.
+%global _missing_build_ids_terminate_build 0
 
 %{!?python_sitelib: %global python_sitelib %(%{__python} -c "from distutils.sysconfig import get_python_lib; print (get_python_lib())")}
 
@@ -14,7 +16,7 @@ Group:         Applications/Databases
 License:       PostgreSQL
 URL:           https://labs.dalibo.com/temboard/
 Source0:       %{pkgname}-%{version}.tar.gz
-BuildArch:     noarch
+Source1:       prometheus
 BuildRoot:     %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
 BuildRequires: python3-rpm-macros
 BuildRequires: python3-setuptools
@@ -47,6 +49,10 @@ This packages holds the web user interface.
 
 %install
 %{__python} setup.py install --root=%{buildroot}
+# Install prometheus binaries in /usr/lib/temboard
+%{__install} -m 755 -d %{buildroot}/usr/lib/temboard
+%{__install} -m 755 %{SOURCE1} %{buildroot}/usr/lib/temboard/prometheus
+
 # config file
 %{__install} -d -m 755 %{buildroot}/%{_sysconfdir}
 %{__install} -d -m 750 %{buildroot}/%{confdir}
@@ -56,6 +62,7 @@ This packages holds the web user interface.
 /usr/share/temboard/*
 /usr/bin/temboard
 %{_unitdir}/temboard.service
+/usr/lib/temboard/*
 
 %post
 /usr/share/temboard/postinst.sh "$@"
@@ -72,6 +79,7 @@ if ! [ -v SMOKETEST ] ; then
 fi
 temboard --version
 test -f /usr/lib/python*/site-packages/temboardui/static/dist/.vite/manifest.json
+test -x /usr/lib/temboard/prometheus
 
 %changelog
 * Fri Oct 14 2022 Dalibo Labs <contact@dalibo.com> - 8.0-1
diff --git a/ui/share/auto_configure.sh b/ui/share/auto_configure.sh
index e0c89fa07..a4540d4ae 100755
--- a/ui/share/auto_configure.sh
+++ b/ui/share/auto_configure.sh
@@ -126,12 +126,33 @@ generate_configuration() {
 
 	[monitoring]
 	# purge_after = 730
+	prometheus = $(find_prometheus)
 
 	[statements]
 	# purge_after = 7
 	EOF
 }
 
+find_prometheus() {
+	local bin
+	bin=/usr/lib/temboard/prometheus
+	if [ -x "$bin" ] ; then
+		echo "$bin"
+		return
+	fi
+	if bin="$(type -p prometheus)" ; then
+		echo "$bin"
+		return
+	fi
+	# .../temboard/workdir/etc/ui/...
+	bin="$ETCDIR/../../../ui/build/prometheus"
+	if [ -x "$bin" ] ; then
+		echo "$bin"
+		return
+	fi
+	return 1
+}
+
 pwgen() {
 	# Generates a random password of 32 hexadecimal characters.
 	od -vN $((${1-32} / 2)) -An -tx1 /dev/urandom | tr -d ' \n'
diff --git a/ui/temboardui/__main__.py b/ui/temboardui/__main__.py
index 3d3987f92..644f46a1f 100644
--- a/ui/temboardui/__main__.py
+++ b/ui/temboardui/__main__.py
@@ -34,9 +34,8 @@ def main(*a, **kw):
     # Load sub commands.
     __import__(__package__ + ".cli.apikey")
     __import__(__package__ + ".cli.generate_key")
-    # Don't import prometheus command yet.
-    # Use python -m temboardui.cli.prometheus until 9.0.
     __import__(__package__ + ".cli.migratedb")
+    __import__(__package__ + ".cli.prometheus")
     __import__(__package__ + ".cli.query_agent")
     __import__(__package__ + ".cli.register_instance")
     __import__(__package__ + ".cli.routes")
diff --git a/ui/temboardui/cli/apikey.py b/ui/temboardui/cli/apikey.py
index e6e2f56c8..8c8120f51 100644
--- a/ui/temboardui/cli/apikey.py
+++ b/ui/temboardui/cli/apikey.py
@@ -1,7 +1,5 @@
 import logging
-import string
 import sys
-from secrets import choice
 from textwrap import dedent
 
 from ..model import Session
@@ -31,7 +29,7 @@ def define_arguments(self, parser):
     def main(self, args):
         session = Session()
         key = (
-            ApiKeys.insert(secret=generate_secret(), comment=args.comment)
+            ApiKeys.insert(secret=ApiKeys.generate_secret(), comment=args.comment)
             .with_session(session)
             .scalar()
         )
@@ -101,10 +99,3 @@ def main(self, args):
             logger.info("Purged %d keys.", count)
         else:
             logger.info("No expired keys to purge.")
-
-
-_SECRET_LETTERS = string.ascii_letters + string.digits + "+/-_"
-
-
-def generate_secret(length=40):
-    return "".join(choice(_SECRET_LETTERS) for _ in range(length))
diff --git a/ui/temboardui/cli/app.py b/ui/temboardui/cli/app.py
index 0b7e4ac84..bbc0ee51b 100644
--- a/ui/temboardui/cli/app.py
+++ b/ui/temboardui/cli/app.py
@@ -1,5 +1,6 @@
 import logging.config
 import os
+import shutil
 import sys
 from argparse import _VersionAction
 from concurrent.futures import ThreadPoolExecutor
@@ -12,6 +13,7 @@
 from tornado.httpserver import HTTPServer
 from tornado.wsgi import WSGIContainer
 
+from .. import prometheus
 from ..autossl import AutoHTTPSServer
 from ..core import workers
 from ..model import QUERIES
@@ -106,6 +108,10 @@ def main(self, argv, environ):
 
         self.webservice = TornadoService(self)
 
+        self.prometheus = prometheus.Manager(app=self)
+        # Not appending prometheus to services, because prometheus does not
+        # need apply_config.
+
         # TaskList engine setup must be done before we load the plugins
         self.scheduler.task_list_engine = TaskListSQLite3Engine(
             os.path.join(self.config.temboard["home"], "server_tasks.db")
@@ -132,7 +138,7 @@ def apply_config(self):
         self.tornado_app.engine = configure_db_session(self.config.repository)
 
     def log_versions(self):
-        versions = inspect_versions()
+        versions = inspect_versions(prometheusbin=self.config.monitoring.prometheus)
         logger.debug("Running on %s %s.", versions["distname"], versions["distversion"])
         logger.debug(
             "Using Python %s (%s) and Tornado %s .",
@@ -146,6 +152,7 @@ def log_versions(self):
             versions["psycopg2"],
             versions["sqlalchemy"],
         )
+        logger.debug("Using Prometheus %s.", versions["prometheus"])
 
 
 class TemboardUIConfiguration(MergedConfiguration):
@@ -270,7 +277,6 @@ def __init__(self, app):
         self.app = app
         # Ref to services.BackgroundManager
         self.background = None
-        # For services.run()
         self.perf = perf.PerfCounters.setup(service=self.name)
 
     def __str__(self):
@@ -280,8 +286,10 @@ def __str__(self):
     def create_loop(self):
         return tornado.ioloop.IOLoop.instance()
 
-    def setup(self):
+    def setup(self, sgm, bg):
+        self.background = bg
         if self.perf:
+            sgm.register(self.perf)
             self.perf.run()
 
         flask_app.vitejs.read_manifest()
@@ -347,9 +355,10 @@ def _setup_autoreload(self):
             autoreload.watch(path)
 
     def _autoreload_hook(self):
-        if self.background:
-            logger.debug("Stopping background service before reloading.")
-            self.background.stop()
+        if not self.background:
+            return
+        logger.debug("Stopping background service before reloading.")
+        self.background.stop()
 
     def _iter_template_files(self):
         rootpkg = __import__(__name__)
@@ -436,6 +445,8 @@ def list_options_specs():
 
     s = "monitoring"
     yield OptionSpec(s, "purge_after", default=730, validator=v.nday)
+    prometheus = shutil.which("prometheus") or OptionSpec.REQUIRED
+    yield OptionSpec(s, "prometheus", default=prometheus, validator=v.file_)
 
     s = "statements"
     yield OptionSpec(s, "purge_after", default=7, validator=v.nday)
diff --git a/ui/temboardui/cli/prometheus.py b/ui/temboardui/cli/prometheus.py
index d58225eb8..c5172bfa4 100644
--- a/ui/temboardui/cli/prometheus.py
+++ b/ui/temboardui/cli/prometheus.py
@@ -12,20 +12,12 @@
 # `temBoard prometheus` with a dedicated dashboard.
 #
 import logging
-import os
-import signal
-import subprocess
 import sys
-from datetime import datetime
 
-import jinja2
-
-import temboardui
-
-from ..model import Session, orm
+from .. import prometheus
+from ..toolkit import services
 from ..toolkit.app import SubCommand
 from ..toolkit.errors import UserError
-from ..toolkit.services import Service
 from .app import app
 
 logger = logging.getLogger(__package__ + ".prometheus")
@@ -39,167 +31,13 @@ class Prometheus(SubCommand):
 
     """
 
+    is_service = True
+
     def main(self, args):
         if not self.app.config.monitoring.prometheus:
             raise UserError("missing prometheus binary")
 
-        prometheus = PrometheusService(app=self.app)
-        with prometheus:
-            prometheus.run()
-
-
-class PrometheusService(Service):
-    def __init__(self, **kwargs):
-        super().__init__(name="prometheus manager", **kwargs)
-        self.proc = None
-
-    @property
-    def pidfile(self):
-        return self.app.config.temboard.home + "/prometheus.pid"
-
-    @property
-    def home(self):
-        return self.app.config.temboard.home + "/prometheus"
-
-    def serve(self):
-        self.terminate_running_prometheus(self.pidfile)
-
-        logger.info("Provisionning Prometheus in %s.", self.home)
-        provision_prometheus(self.app, self.home)
-        logger.info("Starting %s.", self.app.config.monitoring.prometheus)
-        cmd = [
-            self.app.config.monitoring.prometheus,
-            f"--config.file={self.home}/prometheus.yml",
-            # 0.0.0.0 is reachable from dev grafana for testing purpose.
-            # Once we have alertmanager, use localhost.
-            "--web.listen-address=0.0.0.0:8890",
-            "--log.level=debug",
-            "--storage.tsdb.retention.time=1h",
-        ]
-        self.proc = subprocess.Popen(cmd, cwd=self.home)
-        logger.info("Started Prometheus as PID %s.", self.proc.pid)
-        with open(self.pidfile, "w") as fo:
-            fo.write(str(self.proc.pid))
-        self.setup_instances()
-        logger.debug("Waiting prometheus service forever.")
-        self.proc.wait()
-
-    def terminate_running_prometheus(self, pidfile):
-        if not os.path.exists(pidfile):
-            return
-
-        with open(pidfile) as fo:
-            pid = fo.read()
-
-        try:
-            logger.debug("Eventually terminating Prometheus PID %s.", pid)
-            os.kill(int(pid), signal.SIGTERM)
-            logger.info("Prometheus running as PID %s. Terminating.", pid)
-        except OSError:
-            logger.debug("Spurious PID file %s.", pidfile)
-
-    def setup_instances(self):
-        session = Session()
-        for (instance,) in session.execute(orm.Instances.all()):
-            if not instance.discover:
-                logger.debug("Skipping unreachable instance %s.", instance)
-                continue
-            if instance.discover["temboard"]["agent_version"] < "8":
-                logger.debug("Skipping old agent %s.", instance)
-                continue
-            provision_instance(self.app, instance)
-            self.proc.send_signal(signal.SIGHUP)
-
-    def reload(self):
-        super().reload()
-        if self.proc:
-            self.proc.send_signal(signal.SIGHUP)
-
-    def teardown(self):
-        if not self.proc:
-            return
-        logger.info("Stopping Prometheus.")
-        self.proc.terminate()
-        self.proc = None
-        os.unlink(self.app.config.temboard.home + "/prometheus.pid")
-
-
-def provision_prometheus(app, home):
-    logger.debug("Ensure prometheus home is created.")
-    os.makedirs(home + "/instances.d", exist_ok=True)
-    t = jinja2.Template(
-        source=PROMETHEUS_CONFIG_TEMPLATE,
-        trim_blocks=True,
-        lstrip_blocks=True,
-        undefined=jinja2.StrictUndefined,
-        keep_trailing_newline=True,
-    )
-    conf = t.render(
-        app=app,
-        apikey="UNSECURE_DEV_APIKEY",
-        home=home,
-        now=datetime.utcnow(),
-        temboard_version=temboardui.__version__,
-    )
-    with open(home + "/prometheus.yml", "w") as fo:
-        os.chmod(fo.name, 0o600)
-        fo.write(conf)
-
-
-PROMETHEUS_CONFIG_TEMPLATE = """\
-# This file is generated by temBoard. Do not edit.
-#
-# Generation Date: {{ now }}
-# temBoard Version: {{ temboard_version }}
-#
-scrape_configs:
-- job_name: temboard
-  scrape_interval: 60s
-  scheme: http
-  authorization:
-    type: Bearer
-    credentials: {{ apikey }}
-  file_sd_configs:
-  - files:
-    - instances.d/instance-*.yml
-"""
-
-
-def provision_instance(app, instance):
-    logger.info("Provisionning %s.", instance)
-    t = jinja2.Template(
-        source=INSTANCE_CONFIG_TEMPLATE,
-        trim_blocks=True,
-        lstrip_blocks=True,
-        undefined=jinja2.StrictUndefined,
-        keep_trailing_newline=True,
-    )
-    conf = t.render(
-        app=app,
-        instance=instance,
-        now=datetime.utcnow(),
-        temboard_version=temboardui.__version__,
-    )
-    path = "{}/prometheus/instances.d/instance-{}-{}.scrape.yml".format(
-        app.config.temboard.home, instance.agent_address, instance.agent_port
-    )
-    with open(path, "w") as fo:
-        os.chmod(fo.name, 0o600)
-        fo.write(conf)
-
-
-INSTANCE_CONFIG_TEMPLATE = """\
-# This file is generated by temBoard. Do not edit.
-#
-# Generation Date: {{ now }}
-# temBoard Version: {{ temboard_version }}
-#
-- targets: [localhost:8888]
-  labels:
-    __metrics_path__: "/proxy/{{ instance.agent_address }}/{{ instance.agent_port }}/monitoring/metrics"
-    instance:  "{{ instance.hostname }}:{{ instance.pg_port }}"
-    agent:  "{{ instance.agent_address }}:{{ instance.agent_port }}"
-"""  # noqa
+        return services.run(prometheus.Manager(app=self.app))
 
 
 if "__main__" == __name__:
diff --git a/ui/temboardui/cli/serve.py b/ui/temboardui/cli/serve.py
index e1065c11a..5d3b2913b 100644
--- a/ui/temboardui/cli/serve.py
+++ b/ui/temboardui/cli/serve.py
@@ -14,4 +14,9 @@ def main(self, args):
         check_schema()
         self.app.config.load_signing_key()
 
-        services.run(self.app.webservice, self.app.scheduler, self.app.worker_pool)
+        services.run(
+            self.app.webservice,
+            self.app.scheduler,
+            self.app.worker_pool,
+            self.app.prometheus,
+        )
diff --git a/ui/temboardui/handlers/home.py b/ui/temboardui/handlers/home.py
index 16017dda7..618aa77d5 100644
--- a/ui/temboardui/handlers/home.py
+++ b/ui/temboardui/handlers/home.py
@@ -16,7 +16,7 @@ def home(request):
 
 @app.route("/about")
 def about(request):
-    versions_info = inspect_versions()
+    versions_info = inspect_versions(prometheusbin=request.config.monitoring.prometheus)
     instances = request.db_session.scalar(Instances.count())
     roles = request.db_session.scalar(Roles.count())
     infos = {
@@ -29,6 +29,7 @@ def about(request):
         "Tornado": versions_info["tornado"],
         "libpq": versions_info["libpq"],
         "psycopg2": versions_info["psycopg2"],
+        "Prometheus": "%(prometheus)s (%(prometheusbin)s)" % versions_info,
         "SQLAlchemy": versions_info["sqlalchemy"],
         "Instances": instances,
         "Users": roles,
diff --git a/ui/temboardui/handlers/settings/instance.py b/ui/temboardui/handlers/settings/instance.py
index 0702fbeb2..a80e718d0 100644
--- a/ui/temboardui/handlers/settings/instance.py
+++ b/ui/temboardui/handlers/settings/instance.py
@@ -57,6 +57,7 @@ def create_instance_helper(request, data):
     if "monitoring" in plugins:
         from ...plugins.monitoring import collector as monitoring_collector
 
+        app.prometheus.trigger_reload()
         logger.info("Schedule monitoring collect for agent now.")
         monitoring_collector.defer(
             app, address=data["new_agent_address"], port=data["new_agent_port"]
@@ -180,6 +181,7 @@ def json_delete_instance(request):
     if not data.get("agent_port"):
         raise HTTPError(400, "Agent port field is missing.")
     delete_instance(request.db_session, **data)
+    request.handler.application.temboard_app.prometheus.trigger_reload()
     return {"delete": True}
 
 
diff --git a/ui/temboardui/model/orm.py b/ui/temboardui/model/orm.py
index 2ee71161c..c2b7ba374 100644
--- a/ui/temboardui/model/orm.py
+++ b/ui/temboardui/model/orm.py
@@ -1,4 +1,6 @@
 import datetime
+import string
+from secrets import choice
 
 from past.builtins import basestring
 from past.utils import old_div
@@ -137,6 +139,12 @@ class ApiKeys(Model):
     cdate = Column(TIMESTAMP(timezone=True))
     edate = Column(TIMESTAMP(timezone=True))
 
+    _SECRET_LETTERS = string.ascii_letters + string.digits + "+/-_"
+
+    @classmethod
+    def generate_secret(cls, length=40):
+        return "".join(choice(cls._SECRET_LETTERS) for _ in range(length))
+
     # See
     # https://docs.sqlalchemy.org/en/14/orm/queryguide.html#getting-orm-results-from-textual-and-core-statements
 
diff --git a/ui/temboardui/plugins/monitoring/__init__.py b/ui/temboardui/plugins/monitoring/__init__.py
index f98b5ca34..34ea3694c 100644
--- a/ui/temboardui/plugins/monitoring/__init__.py
+++ b/ui/temboardui/plugins/monitoring/__init__.py
@@ -21,7 +21,6 @@
 
 import logging
 import os
-import shutil
 from datetime import datetime, timedelta
 
 try:
@@ -49,7 +48,6 @@
 from ...core import refresh_discover
 from ...model import Session
 from ...toolkit import taskmanager
-from ...toolkit import validators as v
 from ...toolkit.configuration import OptionSpec
 from ...toolkit.errors import UserError
 from .alerting import check_specs
@@ -75,11 +73,7 @@
 
 class MonitoringPlugin:
     s = "monitoring"
-    prometheus = shutil.which("prometheus")
-    options_specs = [
-        OptionSpec(s, "collect_max_duration", default=30, validator=int),
-        OptionSpec(s, "prometheus", default=prometheus, validator=v.file_),
-    ]
+    options_specs = [OptionSpec(s, "collect_max_duration", default=30, validator=int)]
 
     def __init__(self, app):
         self.app = app
diff --git a/ui/temboardui/prometheus.py b/ui/temboardui/prometheus.py
new file mode 100644
index 000000000..7cf034f2a
--- /dev/null
+++ b/ui/temboardui/prometheus.py
@@ -0,0 +1,256 @@
+# Bridge temBoard and Prometheus
+#
+# - Configure Prometheus with a dedicated API key.
+# - Refresh prometheus configuration on SIGHUP and every 5 minutes.
+#
+import glob
+import logging
+import os
+import re
+import signal
+import subprocess
+import time
+from datetime import datetime, timedelta
+
+import jinja2
+
+import temboardui
+
+from .model import Session, orm
+from .toolkit import syncio
+
+logger = logging.getLogger(__name__)
+
+
+class Prometheus:
+    name = "prometheus"
+
+    def __init__(self, binpath, home):
+        self.binpath = binpath
+        self.home = home
+
+    def __str__(self):
+        return self.name
+
+    # For services.BackgroundManager
+    @property
+    def pidfile(self):
+        return f"{self.home}/{self}.pid"
+
+    # For services.execute()
+    def setup(self):
+        os.chdir(self.home)
+
+    @property
+    def command(self):
+        return [
+            self.binpath,
+            f"--config.file={self.home}/prometheus.yml",
+            # 0.0.0.0 is reachable from dev grafana for testing purpose.
+            # Once we embed alertmanager, use localhost.
+            "--web.listen-address=0.0.0.0:8890",
+            "--log.level=debug",
+            "--storage.tsdb.retention.time=1h",
+        ]
+
+
+class Manager(syncio.Service):
+    name = "prometheus manager"
+
+    def __init__(self, app):
+        self.app = app
+        self.sighup = False
+        self.provisionner = Provisionner(self.home)
+        self.configuration_expiry = None
+        # Set by services.BackgroundManager
+        self.pid = None
+
+    def trigger_reload(self):
+        logger.debug("Triggering Prometheus configuration reload. pid=%s", self.pid)
+        os.kill(self.pid, signal.SIGHUP)
+
+    @property
+    def home(self):
+        return self.app.config.temboard.home + "/prometheus"
+
+    # Interface for SignalMultiplexer
+    def sighup_handler(self, *_):
+        self.sighup = True
+
+    # Interface for services.run
+    def setup(self, sgm, bg):
+        logger.info("Provisionning Prometheus in %s.", self.home)
+        logger.debug("Creating temBoard API key.")
+        session = Session()
+        key = (
+            orm.ApiKeys.insert(
+                secret=orm.ApiKeys.generate_secret(),
+                comment="temboard prometheus access",
+            )
+            .with_session(session)
+            .scalar()
+        )
+        session.commit()
+
+        self.provisionner.setup_global(key.secret)
+        self._setup_instances()
+
+        self.background = bg
+        bg.add(Prometheus(self.app.config.monitoring.prometheus, self.home))
+        sgm.register(bg)
+
+    # Interface for syncio.Loop
+    def accept(self):
+        if self.configuration_expiry < datetime.utcnow():
+            logger.debug("Prometheus configuration expired.")
+            self._setup_instances()
+            self.sighup = False
+
+        if self.sighup:
+            self.sighup = False
+            self.app.reload()
+            self._setup_instances()
+
+        time.sleep(1)
+
+    def _setup_instances(self):
+        provisionner = Provisionner(self.home)
+        provisionner.inspect()
+
+        session = Session()
+        for instance in session.execute(orm.Instances.all()):
+            # DEPRECATED: SQAlchemy 1.4+ returns a tuple of objects
+            if len(instance) == 1:
+                (instance,) = instance
+
+            if not instance.discover:
+                logger.debug("Skipping unreached instance %s.", instance)
+                continue
+            provisionner.setup_instance(instance)
+
+        provisionner.purge()
+
+        self.configuration_expiry = datetime.utcnow() + timedelta(minutes=5)
+        if hasattr(self, "background"):
+            self.background.kill(signal.SIGHUP)
+
+
+def find(binpath=None):
+    candidates = [
+        binpath,
+        # Package path.
+        "/usr/lib/temboard/prometheus",
+        # Development path for CI.
+        "ui/build/bin/prometheus",
+    ]
+    for binpath in candidates:
+        if not binpath:
+            continue
+        if os.path.exists(binpath):
+            return binpath
+
+
+def version(binpath):
+    if not binpath:
+        return "n/a"
+    out = subprocess.run([binpath, "--version"], stdout=subprocess.PIPE, check=True)
+    m = re.search(r"version (\d+\.\d+\.\d+)", out.stdout.decode())
+    if not m:
+        logger.warning("Failed to parse Prometheus version from %s", out.stdout)
+        return "n/a"
+    return m.group(1)
+
+
+class Provisionner:
+    def __init__(self, home):
+        self.home = home
+        self.spurious_files = []
+
+    def inspect(self):
+        self.spurious_files = glob.glob(self.home + "/instances.d/instance-*.yml")
+
+    def setup_global(self, apikey):
+        os.makedirs(self.home + "/instances.d", exist_ok=True)
+        t = jinja2.Template(
+            source=PROMETHEUS_CONFIG_TEMPLATE,
+            trim_blocks=True,
+            lstrip_blocks=True,
+            undefined=jinja2.StrictUndefined,
+            keep_trailing_newline=True,
+        )
+        conf = t.render(
+            apikey=apikey,
+            home=self.home,
+            now=datetime.utcnow(),
+            temboard_version=temboardui.__version__,
+        )
+        with open(self.home + "/prometheus.yml", "w") as fo:
+            os.chmod(fo.name, 0o600)
+            fo.write(conf)
+
+    def setup_instance(self, instance):
+        path = "{}/instances.d/instance-{}-{}.scrape.yml".format(
+            self.home, instance.agent_address, instance.agent_port
+        )
+        logger.debug(
+            "Configuring Prometheus scaping. instance=%s file=%s",
+            instance,
+            os.path.basename(path),
+        )
+        t = jinja2.Template(
+            source=INSTANCE_CONFIG_TEMPLATE,
+            trim_blocks=True,
+            lstrip_blocks=True,
+            undefined=jinja2.StrictUndefined,
+            keep_trailing_newline=True,
+        )
+        conf = t.render(
+            instance=instance,
+            now=datetime.utcnow(),
+            temboard_version=temboardui.__version__,
+        )
+        with open(path, "w") as fo:
+            os.chmod(fo.name, 0o600)
+            fo.write(conf)
+        if path in self.spurious_files:
+            self.spurious_files.remove(path)
+        return path
+
+    def purge(self):
+        for path in self.spurious_files:
+            logger.debug("Purging configuration file %s.", os.path.basename(path))
+            os.unlink(path)
+        self.spurious_files = []
+
+
+PROMETHEUS_CONFIG_TEMPLATE = """\
+# This file is generated by temBoard. Do not edit.
+#
+# Generation Date: {{ now }}
+# temBoard Version: {{ temboard_version }}
+#
+scrape_configs:
+- job_name: temboard
+  scrape_interval: 60s
+  scheme: http
+  authorization:
+    type: Bearer
+    credentials: "{{ apikey }}"
+  file_sd_configs:
+  - files:
+    - instances.d/instance-*.yml
+"""
+
+
+INSTANCE_CONFIG_TEMPLATE = """\
+# This file is generated by temBoard. Do not edit.
+#
+# Generation Date: {{ now }}
+# temBoard Version: {{ temboard_version }}
+#
+- targets: [localhost:8888]
+  labels:
+    __metrics_path__: "/proxy/{{ instance.agent_address }}/{{ instance.agent_port }}/monitoring/metrics"
+    instance:  "{{ instance.hostname }}:{{ instance.pg_port }}"
+    agent:  "{{ instance.agent_address }}:{{ instance.agent_port }}"
+"""  # noqa
diff --git a/ui/temboardui/toolkit/services.py b/ui/temboardui/toolkit/services.py
index 6194e320a..710e71a21 100644
--- a/ui/temboardui/toolkit/services.py
+++ b/ui/temboardui/toolkit/services.py
@@ -26,6 +26,8 @@
 # - pkill -ef 'temboard: web' -KILL: scheduler and worker pool should stop.
 # - pkill -ef 'temboard: scheduler' -KILL: scheduler is restarted
 # - pkill -ef 'temboard: web' -HUP : all process must reload configuration
+# - pkill -ef 'temboard: prometheus' -KILL: prometheus is restarted.
+# - pkill -e prometheus -KILL: prometheus is restarted.
 # - Tornado autoreload: all processes are restarted.
 #
 # Same for temBoard agent.
@@ -42,7 +44,7 @@
 
 
 def run(main, *backgrounds):
-    """Execute a main service object function in this process.
+    """Run a main service object function in this process.
 
     Handle signals for INT, TERM, HUP, CHLD and ALRM.
     Handle background services.
@@ -61,17 +63,13 @@ def run(main, *backgrounds):
     sgm.register(LoopStopper(loop))
     sgm.register(main)
 
-    # for tornado autoreload. See TornadoService._autoreload_hook.
-    main.background = bg = BackgroundManager(loop)
+    bg = BackgroundManager(loop)
     if backgrounds:
         for service in backgrounds:
             bg.add(service)
         sgm.register(bg)
 
-    if getattr(main, "perf", None):
-        sgm.register(main.perf)
-
-    main.setup()
+    main.setup(sgm, bg)
     with sgm, bg:
         logger.debug("Entering %s loop.", main)
         loop.start()
@@ -81,6 +79,25 @@ def run(main, *backgrounds):
     return 0
 
 
+def execute(service):
+    """Execute an external command in this process.
+
+    Replace current Python program by a command.
+    """
+
+    if hasattr(service, "setup"):
+        service.setup()
+
+    # forking from asyncio loop requires reset of wakeup_fd.
+    signal.set_wakeup_fd(-1)
+    for fd in range(3, os.sysconf("SC_OPEN_MAX")):
+        try:
+            os.close(fd)
+        except OSError:
+            pass
+    os.execvp(service.command[0], service.command)
+
+
 class LoopStopper:
     def __init__(self, loop):
         self.loop = loop
@@ -110,9 +127,20 @@ def __init__(self, loop):
     def add(self, service):
         self.services[str(service)] = service
 
+    def __bool__(self):
+        return bool(self.services)
+
     def __enter__(self):
         if not self.services:
             return
+
+        self._read_pids()
+
+        if self.pids:
+            logger.debug("Cleaning previous background services.")
+            self.kill()
+            if self.wait():
+                raise Exception("Background services are still alive.")
         self.start()
 
     def __exit__(self, *a):
@@ -132,17 +160,51 @@ def fork(self, service):
         pid = os.fork()
         if pid:  # Parent process
             logger.debug("Background service started. service=%s pid=%d", service, pid)
-            self.pids[str(service)] = pid
+            self._save_pid(service, pid)
             return pid
 
         # Child process
-        os._exit(run(service))
+        if hasattr(service, "pidfile"):
+            execute(service)
+        else:
+            os._exit(run(service))
+
+    def _read_pids(self):
+        for name, service in self.services.items():
+            if not hasattr(service, "pidfile"):
+                continue
+            if not os.path.exists(service.pidfile):
+                continue
+            with open(service.pidfile) as fo:
+                self.pids[name] = int(fo.read().strip())
+                logger.debug(
+                    "Read pid from pidfile. service=%s pid=%d", name, self.pids[name]
+                )
+
+    def _save_pid(self, service, pid):
+        service.pid = pid
+        self.pids[str(service)] = pid
+        if hasattr(service, "pidfile"):
+            with open(service.pidfile, "w") as fo:
+                fo.write(str(pid))
+
+    def _drop_pid(self, name):
+        del self.pids[name]
+        s = self.services[name]
+        s.pid = None
+        if not hasattr(s, "pidfile"):
+            return
+        if os.path.exists(s.pidfile):
+            os.unlink(s.pidfile)
 
     def stop(self):
         self.stopping = True
         for name, pid in self.pids.items():
             logger.debug("Terminating background service. service=%s pid=%d", name, pid)
-            os.kill(pid, signal.SIGTERM)
+            try:
+                os.kill(pid, signal.SIGTERM)
+            except ProcessLookupError:
+                pass
         time.sleep(0.125)
         if self.wait():
             self.kill()
@@ -160,20 +222,25 @@ def wait(self, timeout=5, step=0.5):
                 try:
                     pid, status = os.waitpid(-1, os.WNOHANG)
                 except ChildProcessError:
-                    break
+                    pass
                 if pid:
-                    del self.pids[name]
+                    self._drop_pid(name)
 
             time.sleep(step)
             timeout -= step
 
         return bool(self.pids)
 
-    def kill(self):
+    def kill(self, sig=signal.SIGKILL):
         for name, pid in self.pids.items():
-            logger.warning("Killing background service. service=%s pid=%s", name, pid)
+            logger.warning(
+                "Signaling background service. service=%s pid=%s signal=%s",
+                name,
+                pid,
+                sig,
+            )
             try:
-                os.kill(pid, signal.SIGKILL)
+                os.kill(pid, sig)
             except ProcessLookupError:
                 pass
 
@@ -195,11 +262,9 @@ def sigchld_handler(self, *a):
                 pass
 
             logger.warning(
-                "Background service dead. Restarting service=%s pid=%s",
-                name,
-                self.pids[name],
+                "Background service dead. Restarting service=%s pid=%s", name, pid
             )
-            del self.pids[name]
+            self._drop_pid(name)
 
         self.start()
 
diff --git a/ui/temboardui/toolkit/taskmanager.py b/ui/temboardui/toolkit/taskmanager.py
index 314e3c50c..451262900 100644
--- a/ui/temboardui/toolkit/taskmanager.py
+++ b/ui/temboardui/toolkit/taskmanager.py
@@ -443,7 +443,6 @@ def __init__(self, app, task_queue, event_queue):
         self.event_queue = event_queue
         self.scheduler = None
         self.task_list_engine = None
-        # For services.run
         self.perf = PerfCounters.setup(service=self.name)
 
     @property
@@ -451,10 +450,11 @@ def address(self):
         return os.path.join(self.app.config.temboard.home, ".tm.socket")
 
     # interface for services.run
-    def setup(self):
+    def setup(self, sgm, *_, **__):
         self.teardown()
         self.scheduler.setup()
         if self.perf:
+            sgm.register(self.perf)
             self.perf.run()
 
     # interface for syncio.Loop
@@ -535,7 +535,6 @@ def __init__(self, task_queue, event_queue):
         self.task_queue = task_queue
         self.event_queue = event_queue
         self.workers = {}
-        # For service.run()
         self.perf = None
 
     def _abort_job(self, task_id):
@@ -789,13 +788,15 @@ class WorkerPoolService(syncio.Service):
     def __init__(self, app, task_queue, event_queue):
         super().__init__(app)
         self.worker_pool = WorkerPool(task_queue, event_queue)
-        # For service.run
         self.perf = PerfCounters.setup(service=self.name)
 
     # interface for services.run
-    def setup(self):
+    def setup(self, sgm, *_, **__):
         self.worker_pool.perf = self.perf
         self.worker_pool.setup()
+        if self.perf:
+            sgm.register(self.perf)
+            self.perf.run()
 
     def teardown(self):
         logger.info("Aborting jobs.")
diff --git a/ui/temboardui/version.py b/ui/temboardui/version.py
index 2753753d0..406b61fae 100644
--- a/ui/temboardui/version.py
+++ b/ui/temboardui/version.py
@@ -1,7 +1,9 @@
+import logging
 import sys
 from platform import python_version
 
 __version__ = "9.0.dev0"
+logger = logging.getLogger(__name__)
 
 
 # This output is parsed by tests/conftest.py::pytest_report_header.
@@ -14,6 +16,7 @@
 libpq %(libpq)s
 psycopg2 %(psycopg2)s
 SQLAlchemy %(sqlalchemy)s
+Prometheus %(prometheus)s (%(prometheusbin)s)
 """
 
 
@@ -21,15 +24,18 @@ def format_version():
     return VERSION_FMT % inspect_versions()
 
 
-def inspect_versions():
+def inspect_versions(prometheusbin=None):
     import cryptography
     from psycopg2 import __version__ as psycopg2_version
     from sqlalchemy import __version__ as sqlalchemy_version
     from tornado import version as tornado_version
 
+    from . import prometheus
     from .toolkit.versions import format_pq_version, read_distinfo, read_libpq_version
 
     distinfos = read_distinfo()
+    prometheusbin = prometheus.find(prometheusbin)
+    prometheus = prometheus.version(prometheusbin)
 
     return dict(
         cryptography=cryptography.__version__,
@@ -43,4 +49,6 @@ def inspect_versions():
         temboard=__version__,
         temboardbin=sys.argv[0],
         tornado=tornado_version,
+        prometheus=prometheus,
+        prometheusbin=prometheusbin or "n/a",
     )