DOCU-2421: Adds monitoring overview page

src/gateway/production/monitoring/index.md

@@ -1,6 +1,26 @@
 ---
 title: Monitoring Overview
-
+content-type: reference
 ---
 
-## PLACEHOLDER Monitoring Overview
+API gateways isolate your applications from the outside world and provide critical path
+protection for your upstream services. Understanding the state of your API gateway
+system is critical to providing reliable API-based systems.
+
+There are many monitoring and alerting systems available, and {{site.base_gateway}} integrates with 
+multiple solutions:
+
+* [Prometheus](https://prometheus.io/) is an open-source systems monitoring and alerting toolkit.
+   Prometheus provides a multi-demensional time series data model and query language.
+   The [Monitoring with Prometheus](/gateway/latest/production/monitoring/prometheus/) guide
+   shows how to install and configure the {{site.base_gateway}} [Prometheus plugin](/hub/kong-inc/prometheus/).
+* [Datadog](https://www.datadoghq.com/) is a popular cloud based infrastructure and application monitoring service.
+   See the [Collect Metrics with Datadog guide](/gateway/latest/production/monitoring/datadog/) for information on 
+   integrating {{site.base_gateway}} with Datadog. You can also integrate the [Datadog plugin](/hub/kong-inc/datadog/) with {{site.base_gateway}} for additional insights.
+* [StatsD](https://github.com/statsd/statsd) is a lightweight network daemon that listens for application metrics on
+   UDP or TCP and sends aggregated values to one or more backend services. {{site.base_gateway}} directly supports StatsD
+   with the [StatsD plugin](/hub/kong-inc/statsd/). [Monitoring with StatsD](/gateway/latest/production/monitoring/statsd/) provides a 
+   step-by-step guide to enabling StatsD.
+
+Closely related to monitoring is tracing. See the {{site.base_gateway}} [Tracing Reference](/gateway/latest/production/tracing/)
+for details about instrumenting your API gateway.