SQL Connection creates excessive concurrent HTTP connections to the host - php

Question

I kept commenting parts of my PHP script till this is what I ended up with. This thing creates about 200 to 300 concurrent connections in under a minute to the SQL ip (checked from the gateway) and I don't understand why.
Shouldn't closing the SQL connection end the communication between the servers?
The php script is being called once a second via JavaScript, I'm the only user on the website.
PHP implementation of the sock (taken from the net, fclose() added as that's how I read socks are closed)
<?php
$cookie="tD2h6";
$data = $_COOKIE[$cookie];
parse_str($data, $output);
$name = $output['name'];
$pass = $output['pass'];
$con=mysqli_connect("89.33.242.99","global","changeme","global");
$sql = 'SELECT * FROM `users` WHERE `username`=?';
# Prepare statement
$stmt = $con->prepare($sql);
if($stmt === false) {
trigger_error('Wrong SQL: ' . $sql . ' Error: ' . $con->errno . ' ' . $con->error, E_USER_ERROR);
}
# Bind parameters. Types: s = string, i = integer, d = double, b = blob
$stmt->bind_param('s', $name);
# Execute statement
$stmt->execute();
$res = $stmt->get_result();
$row = $res->fetch_assoc();
if($row['password']===$pass && !empty($pass))
{
$hisusername = $name;
$hiscredits = $row['credits'];
$hiseuro = $row['euro'];
}
else
{
$hisusername = "Guest";
$hiscredits = "0";
$hiseuro = "0";
}
if (mysqli_connect_errno()) {
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$result = mysqli_query($con,"SELECT * FROM `users`");
$num_rows = mysqli_num_rows($result);
$result = mysqli_query($con,"SELECT * FROM `users` WHERE admlevel>0");
$num_admrows = mysqli_num_rows($result);
$data = array();
$i=1;
$result = mysqli_query($con,"SELECT * FROM jbchat ORDER BY id DESC LIMIT 7");
while($row = mysqli_fetch_array($result))
{
$data[$i] = $row['string'];
$i=$i+1;
}
for($i=7;$i>0;--$i)
{
$jbchat = $jbchat . $data[$i] . "<br>";
}
unset($data);
$data = array();
$i=1;
$result = mysqli_query($con,"SELECT * FROM frchat ORDER BY id DESC LIMIT 7");
while($row = mysqli_fetch_array($result))
{
$data[$i] = $row['string'];
$i=$i+1;
}
for($i=7;$i>0;--$i)
{
$frchat = $frchat . $data[$i] . "<br>";
}
unset($data);
$data = array();
$i=1;
$result = mysqli_query($con,"SELECT * FROM drchat ORDER BY id DESC LIMIT 7");
while($row = mysqli_fetch_array($result))
{
$data[$i] = $row['string'];
$i=$i+1;
}
for($i=7;$i>0;--$i)
{
$drchat = $drchat . $data[$i] . "<br>";
}
unset($data);
$data = array();
$i=1;
$result = mysqli_query($con,"SELECT * FROM cschat ORDER BY id DESC LIMIT 7");
while($row = mysqli_fetch_array($result))
{
$data[$i] = $row['string'];
$i=$i+1;
}
for($i=7;$i>0;--$i)
{
$cschat = $cschat . $data[$i] . "<br>";
}
$today = getdate();
$date = $today['mday'] . "/" . $today['mon'] . "/" . $today['year'];
if($today['minutes']>9)
$time = $today['hours'] . ":" . $today['minutes'];
else
$time = $today['hours'] . ":0" . $today['minutes'];
$sqlx = 'SELECT * FROM notifications WHERE username=? ORDER BY id DESC LIMIT 5';
# Prepare statement
$stmt = $con->prepare($sqlx);
if($stmt === false) {
trigger_error('Wrong SQL: ' . $sqlx . ' Error: ' . $con->errno . ' ' . $con->error, E_USER_ERROR);
}
# Bind parameters. Types: s = string, i = integer, d = double, b = blob
$stmt->bind_param('s', $name);
$stmt->execute();
$res = $stmt->get_result();
while($row = $res->fetch_assoc())
{
if($row['read']==0)
$nnumber = $nnumber+1;
$notifications = $notifications . "
<li>
<a href=\"#\" onclick=\"invisphp2('http://r4ge.ro/php/readnotif.php?notifid=" . $row['id'] . "')\">
<i class=\"fa fa-warning danger\"></i>" . $row['text'] . "
<br>" . $row['date'] . "
</a>
</li>";
}
$result = mysqli_query($con,"SELECT * FROM chat ORDER BY id DESC LIMIT 30");
$data = array();
$i=1;
while($row = mysqli_fetch_array($result))
{
$data[$i] = $row['name'] . ": " . $row['msg'];
$i=$i+1;
}
for($i=30;$i>0;--$i)
{
$lchat = $lchat . $data[$i] . "<br>";
}
echo json_encode(array(
"registered" => $num_rows,
"admins" => $num_admrows,
"time" => $time,
"date" => $date,
"nnumber" => $nnumber,
"notifications" => $notifications,
"lchat" => $lchat,
"hisusername" => $hisusername,
"hiscredits" => $hiscredits,
"hiseuro" => $hiseuro
));
mysqli_close($con);
?>
Edit: after listening to a comment that's now deleted, I removed every single query except the first one, so this code is now being ran, the connections still rocketed to 150 in 20-30 seconds.
<?php
$cookie="tD2h6";
$data = $_COOKIE[$cookie];
parse_str($data, $output);
$name = $output['name'];
$pass = $output['pass'];
$con=mysqli_connect("89.33.242.99","global","changeme","global");
$sql = 'SELECT * FROM `users` WHERE `username`=?';
# Prepare statement
$stmt = $con->prepare($sql);
if($stmt === false) {
trigger_error('Wrong SQL: ' . $sql . ' Error: ' . $con->errno . ' ' . $con->error, E_USER_ERROR);
}
# Bind parameters. Types: s = string, i = integer, d = double, b = blob
$stmt->bind_param('s', $name);
# Execute statement
$stmt->execute();
$res = $stmt->get_result();
$row = $res->fetch_assoc();
if($row['password']===$pass && !empty($pass))
{
$hisusername = $name;
$hiscredits = $row['credits'];
$hiseuro = $row['euro'];
}
else
{
$hisusername = "Guest";
$hiscredits = "0";
$hiseuro = "0";
}
if (mysqli_connect_errno()) {
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
echo json_encode(array(
"registered" => $num_rows,
"admins" => $num_admrows,
"time" => $time,
"date" => $date,
"nnumber" => $nnumber,
"notifications" => $notifications,
"lchat" => $lchat,
"hisusername" => $hisusername,
"hiscredits" => $hiscredits,
"hiseuro" => $hiseuro
));
mysqli_close($con);
?>

Answer 1

I know this will make me look very bad.
Unfortunately there is nothing bad in this particular code.
The problem was at a much deeper level in the site's framework, and the above code being the homepage, lead me to think it was the source of the problem.
To #developerwjk , the answer is no, combining procedural and object oriented implementations has no effect whatsoever on the functionality of mysqli, it works great.
The culprit: lack of mysqli_close() at the end of every single PHP that creates a connection
Don't trust the documentation when it says the connection is closed on script end, put it there just to be safe.