Bug 1928068 - doc: Add ping_info.reason for investigating data issues

docs/user/user/howto/investigating-data-issues/investigating-data-issues.md

@@ -4,65 +4,76 @@ This document outlines several diagnostic categories and the insights they may o
 
 ### 1\. Countries
 
-* Purpose: Identify geographical patterns that could explain anomalies.  
+* Purpose: Identify geographical patterns that could explain anomalies.
 * Column Name: `metadata.geo.country`
-* Considerations:  
-  * Are there ongoing national holidays or similar events that could affect data?  
+* Considerations:
+  * Are there ongoing national holidays or similar events that could affect data?
   * Is the region known for bot activity or unusual behavior?
 
 ### 2\. ISP (Internet Service Provider)
 
 * Purpose: Analyze data at a more granular level than countries to identify potential automation or bot activity.
 * Column Name: `metadata.isp.name`
-* Considerations:  
-  * Could the anomaly be traced back to a single ISP, potentially indicating automation?  
+* Considerations:
+  * Could the anomaly be traced back to a single ISP, potentially indicating automation?
   * Be mindful of the large number of ISPs; consider applying filters (e.g., `HAVING` clause) to exclude smaller ISPs.
 
 ### 3\. Product Version / Build ID
 
-* Purpose: Check if issues began with a specific product version or build.  
+* Purpose: Check if issues began with a specific product version or build.
 * Column Names: `client_info.app_display_version`, `client_info.app_build`
-* Considerations:  
-  * Did the issue arise after a particular version update? If so, collaborate with the product team to identify changes.  
+* Considerations:
+  * Did the issue arise after a particular version update? If so, collaborate with the product team to identify changes.
   * Ensure that the build ID matches a known Mozilla build. If not, it could be a clone, fork, or side-load build.
 
 ### 4\. Glean SDK Version
 
 * Purpose: Determine whether the issue is tied to a specific Glean SDK version.
 * Column Name: `client_info.telemetry_sdk_build`
-* Considerations:  
+* Considerations:
   * Did the anomaly start after an update to Glean? Work with the Glean team to verify version changes.
 
 ### 5\. Other Library Version Changes
 
-* Purpose: Identify possible regressions due to library updates.  
-* Considerations:  
+* Purpose: Identify possible regressions due to library updates.
+* Considerations:
   * Review updates to Application Services, Gecko, and other dependencies (e.g., Viaduct, rkv) that could affect telemetry collection.
 
 ### 6\. OS/Platform SDK Version
 
 * Purpose: Check if Operating System or platform SDK changes are impacting data collection.
 * Column Names: `client_info.os_version` (Android only: `client_info.android_sdk_version`)
-* Considerations:  
+* Considerations:
   * Have there been changes to platform lifecycle events or background task behaviors (e.g., 0-duration pings, or ping submission issues)?
   * Has the OS changed the behaviour of system APIs?
 
 ### 7\. Time Differences: start/end\_time vs. submission\_timestamp
 
 * Purpose: Assess the delay between telemetry collection and submission.
 * Column Names: `ping_info.parsed_start_time`, `ping_info.parsed_end_time`, `submission_timestamp`
-* Considerations:  
+* Considerations:
   * Are the recorded timestamps reasonable, both in terms of the ping time window and the delay from collection to submission?
 
 ### 8\. Glean Errors
 
-* Purpose: Identify [telemetry or network errors](../../metrics/error-reporting.md) related to data collection.  
-* Considerations:  
+* Purpose: Identify [telemetry or network errors](../../metrics/error-reporting.md) related to data collection.
+* Considerations:
   * Are there networking errors, ingestion issues, or other telemetry failures that could be related to the anomaly?
 
 ### 9\. Hardware Details (Manufacturer/Version) (Mobile platforms only)
 
-* Purpose: Determine if the issue is hardware-specific.  
+* Purpose: Determine if the issue is hardware-specific.
 * Column Names: `client_info.device_manufacturer`, `client_info.device_model`
-* Considerations:  
+* Considerations:
   * Does the anomaly occur primarily on older or newer hardware models?
+
+### 10\. Ping reason
+
+* Purpose: Determine the reason a ping was sent.
+* Column Names: `ping_info.reason`
+* Considerations:
+  * Does the anomaly occur primarily for a specific reason?
+  * The built-in pings have different ping reasons based on their schedule
+    * [`baseline` ping schedule and reasons](../../pings/baseline.md#scheduling)
+    * [`metrics` ping schedule and reasons](../../pings/metrics.md#scheduling)
+    * [`events` ping schedule and reasons](../../pings/events.md#scheduling)