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7 years ago
This is how you can test and terminate slow query with polling.

<?php
// Slow SQL Query
      $SelectSql = 'SELECT * FROM SLOW_QUERY';
      $link = mysqli_connect('localhost','user','pass','database');
      mysqli_query($SelectSql, MYSQLI_ASYNC);
      $thread_id = mysqli_thread_id($link);
      // Ignore user abort so we can kill the query
      ignore_user_abort(true);
      $MaxTime = 5; // seconds
      $Overtime = false;
      $StartTime = time();
      do
      {
          // Poll MySQL
        $links = $errors = $reject = array($link);
        $poll = mysqli_poll($links, $errors, $reject, 0, 500000);
         // Check if the connection is aborted and the query was killed
        if (connection_aborted() && mysqli_kill($link, $thread_id)) {
            die();
        }
        $EndTime = time();
        // Check overtime, kill if detected overtime
        if ($EndTime - $StartTime > $MaxTime)
        {
          mysqli_kill($link, $thread_id);
          $Overtime = true;
          echo 'Error: Query took over '.$Overtime.'.';
        }
      } while (!$poll && $Overtime == false);
?>
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