+CPU usage percentage can be derived *"system_cpu_usage"* for springboot applications and *"process_cpu_seconds_total* for non springboot applications using `PromQL <https://prometheus.io/docs/prometheus/latest/querying/basics/>`__ .
+
+Process uptime
+**************
+
+The process uptime in seconds is available via *"process_uptime_seconds"* for springboot applications or *"process_start_time_seconds"* otherwise.
+
+Status of the applications is available via the standard *"up"* metric.
+
+JVM memory metrics
+******************
+
+These metrics begin with the prefix *"jvm_memory_"*.
+There is a lot of data here however, one of the key metric to monitor would be the total heap memory usage, *E.g. sum(jvm_memory_used_bytes{area="heap"})*.
+
+`PromQL <https://prometheus.io/docs/prometheus/latest/querying/basics/>`__ can be leveraged to represent the total or rate of memory usage.
+
+JVM thread metrics
+******************
+
+These metrics begin with the prefix *"jvm_threads_"*. Some of the key data to monitor for are:
+
+- *"jvm_threads_live_threads"* (springboot apps), or *"jvm_threads_current"* (non springboot) shows the total number of live threads, including daemon and non-daemon threads
+- *"jvm_threads_peak_threads"* (springboot apps), or *"jvm_threads_peak"* (non springboot) shows the peak total number of threads since the JVM started
+- *"jvm_threads_states_threads"* (springboot apps), or *"jvm_threads_state"* (non springboot) shows number of threads by thread state
+
+JVM garbage collection metrics
+******************************
+
+There are many garbage collection metrics, with prefix *"jvm_gc_"* available to get deep insights into how the JVM is managing memory. They can be broadly categorized into:
+
+- Pause duration *"jvm_gc_pause_"* for springboot applications gives us information about how long GC took. For non springboot application, the collection duration metrics *"jvm_gc_collection_"* provide the same information.
+- Memory pool size increase can be assessed using *"jvm_gc_memory_allocated_bytes_total"* and *"jvm_gc_memory_promoted_bytes_total"* for springboot applications.
+
+Average garbage collection time and rate of garbage collection per second are key metrics to monitor.
+
+
+Key metrics for Policy API
+--------------------------
+
++-------------------------------------+----------------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+| Metric name | Metric description | Metric labels |
++=====================================+====================================================================================================+=======================================================================================================================================================================+
+| process_uptime_seconds | Uptime of policy-api application in seconds. | |
++-------------------------------------+----------------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+| http_server_requests_seconds_count | Number of API requests filtered by uri, REST method and response status among other labels | "exception": any exception string; "method": REST method used; "outcome": response status string; "status": http response status code; "uri": REST endpoint invoked |
++-------------------------------------+----------------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+| http_server_requests_seconds_sum | Time taken for an API request filtered by uri, REST method and response status among other labels | "exception": any exception string; "method": REST method used; "outcome": response status string; "status": http response status code; "uri": REST endpoint invoked |
++-------------------------------------+----------------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+
+Key metrics for Policy PAP
+--------------------------
+
++-------------------------------------+----------------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+| Metric name | Metric description | Metric labels |
++=====================================+====================================================================================================+=======================================================================================================================================================================+
+| process_uptime_seconds | Uptime of policy-pap application in seconds. | |
++-------------------------------------+----------------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+| http_server_requests_seconds_count | Number of API requests filtered by uri, REST method and response status among other labels | "exception": any exception string; "method": REST method used; "outcome": response status string; "status": http response status code; "uri": REST endpoint invoked |
++-------------------------------------+----------------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+| http_server_requests_seconds_sum | Time taken for an API request filtered by uri, REST method and response status among other labels | "exception": any exception string; "method": REST method used; "outcome": response status string; "status": http response status code; "uri": REST endpoint invoked |
++-------------------------------------+----------------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+| pap_policy_deployments | Number of TOSCA policy deploy/undeploy operations | "operation": Possibles values are deploy, undeploy; "status": Deploy/Undeploy status values - SUCCESS, FAILURE, TOTAL |
++-------------------------------------+----------------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+
+Key metrics for APEX-PDP
+------------------------
+
++---------------------------------------------+-------------------------------------------------------------------------------------+----------------------------------------------------------------------------------------------------------------------+
+| Metric name | Metric description | Metric labels |
++=============================================+=====================================================================================+======================================================================================================================+
+| process_start_time_seconds | Uptime of apex-pdp application in seconds | |
++---------------------------------------------+-------------------------------------------------------------------------------------+----------------------------------------------------------------------------------------------------------------------+
+| pdpa_policy_deployments_total | Number of TOSCA policy deploy/undeploy operations | "operation": Possibles values are deploy, undeploy; "status": Deploy/Undeploy status values - SUCCESS, FAILURE, TOTAL|
++---------------------------------------------+-------------------------------------------------------------------------------------+----------------------------------------------------------------------------------------------------------------------+
+| pdpa_policy_executions_total | Number of TOSCA policy executions | "status": Execution status values - SUCCESS, FAILURE, TOTAL" |
++---------------------------------------------+-------------------------------------------------------------------------------------+----------------------------------------------------------------------------------------------------------------------+
+| pdpa_engine_state | State of APEX engine | "engine_instance_id": ID of the engine thread |
++---------------------------------------------+-------------------------------------------------------------------------------------+----------------------------------------------------------------------------------------------------------------------+
+| pdpa_engine_last_start_timestamp_epoch | Epoch timestamp of the instance when engine was last started to derive uptime from | "engine_instance_id": ID of the engine thread |
++---------------------------------------------+-------------------------------------------------------------------------------------+----------------------------------------------------------------------------------------------------------------------+
+| pdpa_engine_event_executions | Number of APEX event execution counter per engine thread | "engine_instance_id": ID of the engine thread |
++---------------------------------------------+-------------------------------------------------------------------------------------+----------------------------------------------------------------------------------------------------------------------+
+| pdpa_engine_average_execution_time_seconds | Average time taken to execute an APEX policy in seconds | "engine_instance_id": ID of the engine thread |
++---------------------------------------------+-------------------------------------------------------------------------------------+----------------------------------------------------------------------------------------------------------------------+
+
+Key metrics for XACML PDP
+-------------------------
+
++--------------------------------+---------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+| Metric name | Metric description | Metric labels |
++================================+===================================================+==============================================================================================================================================================================================================================+
+| process_start_time_seconds | Uptime of policy-pap application in seconds. | |
++--------------------------------+---------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+| pdpx_policy_deployments_total | Counts the total number of deployment operations | "operation": Possible values are deploy, undeploy |
++--------------------------------+---------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+| pdpx_policy_decisions_total | Counts the total number of decisions | "application": Possible values are Monitoring, Guard, Optimization, Naming, Native, Match; |
+| | | "status": Possible values are permit, deny, indeterminant, not_applicable |
++--------------------------------+---------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+| logback_appender_total | Counts the log entries | level: Counts on a per log level basis. |
++--------------------------------+---------------------------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+
+Key metrics for Drools PDP
+--------------------------