Document metrics in Tarantool 3.0 (#4348)

.gitmodules

@@ -1,12 +1,6 @@
-[submodule "modules/metrics"]
-	path = modules/metrics
-	url = https://github.com/tarantool/metrics.git
 [submodule "modules/luatest"]
 	path = modules/luatest
 	url = https://github.com/tarantool/luatest
-[submodule "modules/grafana-dashboard"]
-	path = modules/grafana-dashboard
-	url = https://github.com/tarantool/grafana-dashboard
 [submodule "modules/tntcxx"]
 	path = modules/tntcxx
 	url = https://github.com/tarantool/tntcxx.git

build_submodules.sh

@@ -11,18 +11,6 @@ po_dest="${project_root}/locale/ru/LC_MESSAGES"
 # Copy Building Tarantool Docs guide
 cp README.rst doc/contributing/docs/_includes/README.rst
 
-
-# Monitoring
-monitoring_root="${project_root}/modules/metrics/doc/monitoring"
-monitoring_dest="${project_root}/doc/book"
-monitoring_grafana_root="${project_root}/modules/grafana-dashboard/doc/monitoring"
-
-# Copy monitoring docs to the right destination
-mkdir -p "${monitoring_dest}"
-cp -rfv "${monitoring_root}" "${monitoring_dest}/"
-cp -rfv "${monitoring_grafana_root}" "${monitoring_dest}/"
-
-
 # Luatest
 luatest_root="${project_root}/modules/luatest"
 luatest_dest="${project_root}/doc/reference/reference_rock/luatest"

doc/book/admin/index.rst

@@ -41,4 +41,4 @@ This chapter includes the following sections:
    os_notes
    bug_reports
    troubleshoot
-   ../monitoring/index
+   monitoring

doc/book/admin/monitoring.rst

@@ -0,0 +1,17 @@
+..  _monitoring:
+
+Monitoring
+==========
+
+Monitoring is the process of capturing runtime information about the instances of a Tarantool cluster using metrics.
+Metrics can indicate various characteristics, such as memory usage, the number of records in spaces, replication status, and so on.
+Typically, metrics are monitored in real time, allowing for the identification of current issues or the prediction of potential ones.
+
+..  toctree::
+    :maxdepth: 1
+    :numbered: 0
+
+    monitoring/getting_started
+    monitoring/grafana_dashboard
+    monitoring/alerting
+    monitoring/metrics_reference