无论如何要阻止Apache服务器重新连接？

Question

我确信由于服务器断开连接并重新连接，我的聊天应用程序正在受到影响。它应该过滤重复的消息，并且大部分都是这样做的。但是，当两个（或更多）相互发送消息的用户同时连接时，他们的消息似乎重复。如果只有一个用户正在查看其消息，则不会发生这种情况。该应用程序正在使用服务器端事件JavaScript API。

无论如何，有没有办法保持连接活着？或者解决这个问题的方法？可能通过服务器端消息过滤？

客户端：

function chat() {
    if (document.getElementById('chat').style.display == "none" || document.getElementById('chat').className != "on") {
        if (window.matchMedia("screen and (max-width: 800px)").matches) {
            document.getElementById('content').className = 'off';
            document.getElementById('chat').className = "on";
            if (document.getElementById('coverPhoto')) {document.getElementById('coverPhoto').className = 'off';}
        } else {
            document.getElementById('chat').style.display = 'block';
        }
        document.getElementById('chatBox').contentDocument.designMode = 'On';
        if (typeof(EventSource) !== "undefined") {
            var source = new EventSource('/ajax/gMessages.php'), last_id, used = {};
            source.addEventListener('message', function(event) {
                var now_id = event.lastEventId;
                if (last_id != now_id && document.getElementById('chatMsgs').innerHTML != event.data) {
                    last_id = event.lastEventId;
                    if (!used[event.data]) {
                        document.getElementById('chatMsgs').innerHTML += event.data;
                        used[event.data] = 1;
                        document.getElementById('chat').scrollTop = document.getElementById('chat').scrollHeight; //keep scrollbar at the bottom
                    }
                }   
            }, false);
        } 
    } else if (document.getElementById('chat').style.display == "block" || document.getElementById('chat').className != "off") {
        if (window.matchMedia("screen and (max-width: 800px)").matches) {
            document.getElementById('content').className = 'on';
            document.getElementById('chat').className = 'off';
            if (document.getElementById('coverPhoto')) {document.getElementById('coverPhoto').className = 'on';}
        } else {
            document.getElementById('chat').style.display = "block";
        }
    }
}

服务器端：

<?php
session_start();
header('Content-Type: text/event-stream');
header('Cache-Control: no-cache');
set_time_limit(0);
include "../includes/config.php"; 
include "../includes/date.php";
function getMessages() {
    $con = new PDO(DB_DSN, DB_USERNAME, DB_PASSWORD);   
    $con->exec("SET CHARACTER SET utf8"); 
    $getMsgs = "SELECT * FROM `messages` WHERE `msg_to` = '$_SESSION[username]' AND `type` = '0' ORDER BY `sent` ASC";
    $receivedMsgs = $con->query($getMsgs); 
    foreach ($receivedMsgs->fetchAll() as $msg) { 
        $getUI = "SELECT `profile_pic`, `full_name`, `username` FROM `users` WHERE `username` = '$msg[msg_from]'";
        $uiQuery = $con->query($getUI);
        while ($UI = $uiQuery->fetch(PDO::FETCH_ASSOC)) { 
            echo "id: {$msg['id']}\n"; 
            echo "data: <article>\n"; 
            echo "data: <img src='{$UI[profile_pic]}' alt='{$UI[full_name]}' />\n"; 
            echo "data: <section class='msgCntnt'>\n";
            echo "data: <p class='timeAgo'>". Agotime($msg[sent]) ."</p>\n"; 
            echo "data: <a href='/profile?u={$UI[username]}'>{$UI['full_name']}</a><br />\n"; 
            echo "data: <h4>@{$msg['msg_from']}</h4>\n"; 
            echo "data: <p>{$msg['message']}</p>\n"; 
            echo "data: </section>\n"; 
            echo "data: </article>\n\n"; 
        } 
            ob_flush();
            flush();
            sleep(1);
    }
}
getMessages();
?>