join fix

.chloggen/mysql-receiver-query-join-fix.yaml

@@ -0,0 +1,29 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. receiver/filelog)
+component: receiver/mysql
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: "Fixed incorrect JOIN condition in querySample.tmpl that was comparing thread.thread_id to processlist.id instead of the correct foreign key thread.processlist_id."
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [46548]
+
+# (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: |
+  The LEFT JOIN with information_schema.processlist was using an incorrect join condition that would fail to properly correlate rows between the performance_schema.threads and information_schema.processlist tables. The fix changes the join condition from `processlist.id = thread.thread_id` to `processlist.id = thread.processlist_id` to use the correct foreign key relationship.
+
+# 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/mysqlreceiver/templates/querySample.tmpl

@@ -20,7 +20,7 @@ FROM
     performance_schema.threads AS thread
     LEFT JOIN performance_schema.events_statements_current AS statement ON statement.thread_id = thread.thread_id
     LEFT JOIN performance_schema.events_waits_current AS wait ON wait.thread_id = thread.thread_id
-    LEFT JOIN information_schema.processlist AS processlist on processlist.id = thread.thread_id
+    LEFT JOIN information_schema.processlist AS processlist on processlist.id = thread.processlist_id
 WHERE
     thread.processlist_state IS NOT NULL
     AND thread.processlist_command != 'Sleep'