[receiver/iis] fixed issue #34924 - monitor application pool uptime (#38183)

<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
#### Description

Added new metrics

* application pool state: Each application pool's state
* application pool uptime: The number of milliseconds an application
pool has been up.

<!-- Issue number (e.g. #1234) or full URL to issue, if applicable. -->
#### Link to tracking issue
#34924 

<!--Describe what testing was performed and which tests were added.-->
#### Testing
Has been tested on a local windows machine.

<!--Describe the documentation added.-->
#### Documentation

Metadata documention has been updated by mdatagen.

<!--Please delete paragraphs that you did not use before submitting.-->

Author: syron

.chloggen/iisreceiver-add-application_pool-metrics.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: iisreceiver
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Added state and uptime metrics for application pools
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [34924]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

receiver/iisreceiver/documentation.md

@@ -126,6 +126,32 @@ The amount of time the server has been up.
 | ---- | ----------- | ---------- |
 | s | Gauge | Int |
 
+## Optional Metrics
+
+The following metrics are not emitted by default. Each of them can be enabled by applying the following configuration:
+
+```yaml
+metrics:
+  <metric_name>:
+    enabled: true
+```
+
+### iis.application_pool.state
+
+The current state of the application pool. (0 - Starting, 1 - Started, 2 - Stopping, 3 - Stopped, 4 - Unknown)
+
+| Unit | Metric Type | Value Type |
+| ---- | ----------- | ---------- |
+| {state} | Gauge | Int |
+
+### iis.application_pool.uptime
+
+The application pools uptime period since the last restart.
+
+| Unit | Metric Type | Value Type |
+| ---- | ----------- | ---------- |
+| {ms} | Gauge | Int |
+
 ## Resource Attributes
 
 | Name | Description | Values | Enabled |

receiver/iisreceiver/internal/metadata/generated_config.go

@@ -1,6 +1,10 @@
 default:
 all_set:
   metrics:
+    iis.application_pool.state:
+      enabled: true
+    iis.application_pool.uptime:
+      enabled: true
     iis.connection.active:
       enabled: true
     iis.connection.anonymous:
@@ -32,6 +36,10 @@ all_set:
       enabled: true
 none_set:
   metrics:
+    iis.application_pool.state:
+      enabled: false
+    iis.application_pool.uptime:
+      enabled: false
     iis.connection.active:
       enabled: false
     iis.connection.anonymous:

receiver/iisreceiver/internal/metadata/generated_config_test.go

@@ -135,3 +135,15 @@ metrics:
     gauge:
       value_type: int
     enabled: true
+  iis.application_pool.state:
+    description: The current state of the application pool. (0 - Starting, 1 - Started, 2 - Stopping, 3 - Stopped, 4 - Unknown)
+    unit: "{state}"
+    gauge:
+      value_type: int
+    enabled: false
+  iis.application_pool.uptime:
+    description: The application pools uptime period since the last restart.
+    unit: "{ms}"
+    gauge:
+      value_type: int
+    enabled: false

receiver/iisreceiver/internal/metadata/generated_metrics.go

@@ -103,6 +103,18 @@ var appPoolPerfCounterRecorders = []perfCounterRecorderConf{
 			},
 		},
 	},
+	{
+		object:   "APP_POOL_WAS",
+		instance: "*",
+		recorders: map[string]recordFunc{
+			"Current Application Pool State": func(mb *metadata.MetricsBuilder, ts pcommon.Timestamp, val float64) {
+				mb.RecordIisApplicationPoolStateDataPoint(ts, int64(val))
+			},
+			"Current Application Pool Uptime": func(mb *metadata.MetricsBuilder, ts pcommon.Timestamp, val float64) {
+				mb.RecordIisApplicationPoolUptimeDataPoint(ts, int64(val))
+			},
+		},
+	},
 }
 
 func recordMaxQueueItemAge(mb *metadata.MetricsBuilder, ts pcommon.Timestamp, val float64) {