release-21.2: sql: add troubleshooting mode session variable

pkg/cli/clisqlcfg/context.go

@@ -204,6 +204,18 @@ func (c *Context) Run(conn clisqlclient.Conn) error {
 		}
 	}
 
+	if err := c.maybeSetTroubleshootingMode(conn); err != nil {
+		return err
+	}
+
 	shell := clisqlshell.NewShell(c.CliCtx, c.ConnCtx, c.ExecCtx, &c.ShellCtx, conn)
 	return shell.RunInteractive(c.cmdIn, c.CmdOut, c.CmdErr)
 }
+
+func (c *Context) maybeSetTroubleshootingMode(conn clisqlclient.Conn) error {
+	if !c.ConnCtx.DebugMode {
+		return nil
+	}
+	// If we are in debug mode, enable "troubleshooting mode".
+	return conn.Exec("SET troubleshooting_mode = on", nil)
+}

pkg/cli/interactive_tests/test_client_side_checking.tcl

@@ -80,6 +80,12 @@ end_test
 start_test "Check that --debug-sql-cli sets suitable simplified client-side options."
 send "$argv sql --debug-sql-cli\r"
 eexpect "Welcome"
+
+# Check that troubleshooting mode is enabled in debug mode.
+eexpect "root@"
+send "show troubleshooting_mode;\r"
+eexpect "on"
+
 eexpect "root@"
 send "\\set display_format csv\r\\set\r"
 eexpect "check_syntax,false"

pkg/sql/exec_log.go

@@ -368,7 +368,7 @@ func (p *planner) maybeLogStatementInternal(
 		p.logEventsOnlyExternally(ctx, eventLogEntry{event: &eventpb.AdminQuery{CommonSQLExecDetails: execDetails}})
 	}
 
-	if telemetryLoggingEnabled {
+	if telemetryLoggingEnabled && !p.SessionData().TroubleshootingMode {
 		// We only log to the telemetry channel if enough time has elapsed from
 		// the last event emission.
 		requiredTimeElapsed := 1.0 / float64(maxEventFrequency)

pkg/sql/exec_util.go

@@ -2984,6 +2984,10 @@ func (m *sessionDataMutator) SetMultipleModificationsOfTable(val bool) {
 	m.data.MultipleModificationsOfTable = val
 }
 
+func (m *sessionDataMutator) SetTroubleshootingModeEnabled(val bool) {
+	m.data.TroubleshootingMode = val
+}
+
 // Utility functions related to scrubbing sensitive information on SQL Stats.
 
 // quantizeCounts ensures that the Count field in the

pkg/sql/logictest/testdata/logic_test/information_schema

@@ -4690,6 +4690,7 @@ transaction_rows_read_log                              0
 transaction_rows_written_err                           0
 transaction_rows_written_log                           0
 transaction_status                                     NoTxn
+troubleshooting_mode                                   off
 
 # information_schema can be used with the anonymous database.
 # It should show information across all databases.

pkg/sql/logictest/testdata/logic_test/pg_catalog

@@ -4117,6 +4117,7 @@ transaction_rows_read_log                              0                   NULL
 transaction_rows_written_err                           0                   NULL      NULL        NULL        string
 transaction_rows_written_log                           0                   NULL      NULL        NULL        string
 transaction_status                                     NoTxn               NULL      NULL        NULL        string
+troubleshooting_mode                                   off                 NULL      NULL        NULL        string
 vectorize                                              on                  NULL      NULL        NULL        string
 
 query TTTTTTT colnames
@@ -4220,6 +4221,7 @@ transaction_rows_read_log                              0                   NULL
 transaction_rows_written_err                           0                   NULL  user     NULL      0                   0
 transaction_rows_written_log                           0                   NULL  user     NULL      0                   0
 transaction_status                                     NoTxn               NULL  user     NULL      NoTxn               NoTxn
+troubleshooting_mode                                   off                 NULL  user     NULL      off                 off
 vectorize                                              on                  NULL  user     NULL      on                  on
 
 query TTTTTT colnames
@@ -4321,6 +4323,7 @@ transaction_rows_read_log                              NULL    NULL     NULL
 transaction_rows_written_err                           NULL    NULL     NULL     NULL        NULL
 transaction_rows_written_log                           NULL    NULL     NULL     NULL        NULL
 transaction_status                                     NULL    NULL     NULL     NULL        NULL
+troubleshooting_mode                                  NULL    NULL     NULL     NULL        NULL
 vectorize                                              NULL    NULL     NULL     NULL        NULL
 
 # pg_catalog.pg_sequence

pkg/sql/logictest/testdata/logic_test/show_source

@@ -118,6 +118,7 @@ transaction_rows_read_log                              0
 transaction_rows_written_err                           0
 transaction_rows_written_log                           0
 transaction_status                                     NoTxn
+troubleshooting_mode                                   off
 vectorize                                              on
 
 query T colnames

pkg/sql/sessiondatapb/session_data.proto

@@ -79,6 +79,11 @@ message SessionData {
   // OnUpdateRehomeRowEnabled controls whether the ON UPDATE rehome_row()
   // will actually trigger on row updates.
   bool on_update_rehome_row_enabled = 17;
+
+  // Troubleshooting mode determines whether we refuse to do additional work with
+  // the query (i.e. collect & emit telemetry data). Troubleshooting mode is
+  // disabled by default.
+  bool troubleshooting_mode = 21;
 }
 
 // DataConversionConfig contains the parameters that influence the output