'ERR_EMPTY_RESPONSE' when using an AJAX live searchbar

Question

I have a live AJAX search bar that bring records from a MySQL database. However when you repeatedly search for records by changing the searchbar the web browsers throws the error 'ERR_EMPTY_RESPONSE'.

ERR_EMPTY_RESPONSE

If you try to refresh the page it crashes for 60 (Approx.) seconds. https://i.sstatic.net/ySAwT.jpg

I'm using a GoDaddy server if it makes any differences.

I have tried increasing the PHP memory limit to 512mb as suggested in other questions. This appeared to make no difference.

This is my Javascript

<script type="text/javascript">
        $(document).ready(function()
        {
            $(".product_check").click(function()
            {
                $("#loader").show();

                var action = 'data';
                var eventname = get_filter_text('eventname');
                var category = get_filter_text('category');
                var year = get_filter_text('year');
                var num = document.getElementById('num').value;

                $.ajax(
                {
                    url:'action.php',
                    method:'POST',
                    data:{action:action, eventname:eventname, category:category, year:year, num:num}, success:function(response)
                    {
                        $("#result").html(response);
                        $("#loader").hide();
                        $("#textChange").text("Filtered Products");
                    }
                });
            });

            $(".tb").keyup(function()
            {
                $("#loader").show();

                var action = 'data';
                var eventname = get_filter_text('eventname');
                var category = get_filter_text('category');
                var year = get_filter_text('year');
                var num = document.getElementById('num').value;

                $.ajax(
                {
                    url:'action.php',
                    method:'POST',
                    data:{action:action, eventname:eventname, category:category, year:year, num:num}, success:function(response)
                    {
                        $("#result").html(response);
                        $("#loader").hide();
                        $("#textChange").text("Filtered Products");
                    }
                });
            });

            function get_filter_text(text_id)
            {
                var filterData = [];
                $('#'+text_id+':checked').each(function()
                                               {
                    filterData.push($(this).val());
                });
                return filterData;
            }
        });
    </script>

this is my backend PHP

if(isset($_POST['action']))
{
    $sql = "SELECT * FROM tb_ETSlips WHERE eventname != ''";

    if(isset($_POST['eventname']))
    {
        $eventname = implode("','", $_POST['eventname']);
        $sql .= "AND eventname IN('" . $eventname . "')";
    }
    if(isset($_POST['year']))
    {
        $year = implode("','", $_POST['year']);
        $sql .= "AND year(timestamp) IN('" . $year . "')";
    }
    if(isset($_POST['category']))
    {
        $category = implode("','", $_POST['category']);
        $sql .= "AND category IN('" . $category . "')";
    }
    if(isset($_POST['num']))
    {
        $num = $_POST['num'];
        $sql .= "AND (number LIKE '%" . $num . "%' ";
        $sql .= "OR name LIKE '%" . $num . "%')";

    }

    $result = $conn->query($sql);
    $output='';

    if($result->num_rows>0)
    {
        while ($row=$result->fetch_assoc())
        {
            $output .='<tr>
            <td>' . $row['timestamp'] . '</td>
            <td>' . $row['number'] . '</td>
            <td>' . $row['dname'] . '</td>
            <td>' . $row['reaction'] . '</td>
            <td>' . $row['et1320'] . '</td>
            <td>' . $row['sp1320'] . '</td>
            <td>' . $row['lane'] . '</td>
            </tr>';
        }
    }
    else
    {
        $output = "<h3>No times found!</h3>";
    }

    echo $output;
}
?>

Answer 1

https://uk.godaddy.com/community/GoCentral-Website-Builder/Too-many-POST-requests-via-AJAX-crashing-site/td-p/7119

"I was having the same issue, 40 POST requests/minute would cause my site to lock up for 1 minute. Found the similar issue here (stackoverflow) with the solution.

SOLUTION:

GoDaddy limts the amount of POST request that can be made, regardless if they say they don't. In my case I needed to use the correct method for the job being used. In my case, I was using POST to go to a PHP site that would then GET information and return it. I changed my POST request to a GET request and the issue went away.

Only use POST when absolutely necessary, GoDaddy will limit."