GitBook: [crypto-org-chain#35] Add the section for Prometheus Metric …

…settings

for-node-hosts/running-nodes/cronos-node-best-practises.md

@@ -20,6 +20,39 @@ In order to make it more convenient for DApps and node hosts to set up a node, w
 * `max_num_outbound_peers` For users on a private network set a higher number of outbound peers to 30 for example.
 * After peers are connected, set it back to its default value. Note that some trial values might be needed to get it right.
 
+### Metrics
+
+Prometheus provides real-time metrics used for event monitoring and alerting. Prometheus metrics can be served on Cronos chain. To enable the Prometheus metrics, you will need to set `instrumentation.prometheus=true` in the `config.toml` file manually.
+
+Metrics will be served under `…/metrics` on `26660` port by default, e.g. `localhost:26660/metrics`. The listening address can be changed in the `config.toml` file (`prometheus_listen_addr`).  
+
+Sample Settings:
+
+```
+#######################################################
+###       Instrumentation Configuration Options     ###
+#######################################################
+[instrumentation]
+
+# When true, Prometheus metrics are served under /metrics on
+# PrometheusListenAddr.
+# Check out the documentation for the list of available metrics.
+prometheus = true
+
+# Address to listen for Prometheus collector(s) connections
+prometheus_listen_addr = ":26660"
+
+# Maximum number of simultaneous connections.
+# If you want to accept a larger number than the default, make sure
+# you increase your OS limits.
+# 0 - unlimited.
+max_open_connections = 3
+
+# Instrumentation namespace
+namespace = "tendermint"
+
+```
+
 ## app.toml
 
 ### pruning