[receiver/sqlserver] Add more metrics (#32932)

**Description:**
This change adds a query, scraper, and some more metrics for data from
the performance counter SQL server table. The query itself is mostly
taken from Telegraf's SQL server plugin. This also reuses the existing
metric `sqlserver.lock.wait.rate`, so now it will be available both from
Windows performance counters, as well as other OSs when directly
connecting to the SQL server instance.

**Naming and format feedback on new metrics would be greatly
appreciated.**

**Link to tracking Issue:** #29865

**Testing:** 
Added tests for the query itself, as well as the new scraper.

Co-authored-by: Daniel Jaglowski <[email protected]>

.chloggen/sqlserver_add_perf_counter_query.yaml

@@ -0,0 +1,32 @@
+# 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: sqlserverreceiver
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Add more metrics
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [29865]
+
+# (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: |
+  Added metrics are:
+  - sqlserver.resource_pool.disk.throttled.read.rate
+  - sqlserver.resource_pool.disk.throttled.write.rate
+  - sqlserver.processes.blocked
+  These metrics are only available when directly connecting to the SQL server instance
+
+# 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: []

receiver/sqlserverreceiver/documentation.md

@@ -246,6 +246,36 @@ This metric is only available when the receiver is configured to directly connec
 | logical_filename | The logical filename of the file being monitored. | Any Str |
 | file_type | The type of file being monitored. | Any Str |
 
+### sqlserver.processes.blocked
+
+The number of processes that are currently blocked
+
+This metric is only available when the receiver is configured to directly connect to SQL Server.
+
+| Unit | Metric Type | Value Type |
+| ---- | ----------- | ---------- |
+| {processes} | Gauge | Int |
+
+### sqlserver.resource_pool.disk.throttled.read.rate
+
+The number of read operations that were throttled in the last second
+
+This metric is only available when the receiver is configured to directly connect to SQL Server.
+
+| Unit | Metric Type | Value Type |
+| ---- | ----------- | ---------- |
+| {reads}/s | Gauge | Int |
+
+### sqlserver.resource_pool.disk.throttled.write.rate
+
+The number of write operations that were throttled in the last second
+
+This metric is only available when the receiver is configured to directly connect to SQL Server.
+
+| Unit | Metric Type | Value Type |
+| ---- | ----------- | ---------- |
+| {writes}/s | Gauge | Double |
+
 ## Resource Attributes
 
 | Name | Description | Values | Enabled |

receiver/sqlserverreceiver/factory.go

@@ -43,6 +43,14 @@ func setupQueries(cfg *Config) []string {
 		queries = append(queries, getSQLServerDatabaseIOQuery(cfg.InstanceName))
 	}
 
+	if cfg.MetricsBuilderConfig.Metrics.SqlserverResourcePoolDiskThrottledReadRate.Enabled ||
+		cfg.MetricsBuilderConfig.Metrics.SqlserverResourcePoolDiskThrottledWriteRate.Enabled ||
+		cfg.MetricsBuilderConfig.Metrics.SqlserverLockWaitRate.Enabled ||
+		cfg.MetricsBuilderConfig.Metrics.SqlserverProcessesBlocked.Enabled {
+
+		queries = append(queries, getSQLServerPerformanceCounterQuery(cfg.InstanceName))
+	}
+
 	return queries
 }