CakePHP email timeout & PHP maximum execution time - email

Question

My application uses an Exchange SMTP server for sending emails. At present we don't have any message queuing in our architecture and emails are sent as part of the HTTP request/response cycle.
Occasionally the Exchange server has issues and times out while the email is sending, and as a result the email doesn't send. Sometimes, Cake recognizes the time out and throws an exception. The application code can catch the exception and report to the user that something went wrong.
However, on other occasions PHP hits its maximum execution time before Cake can throw the exception and so the user just gets an error 500 with no useful information as to what happened.
In an effort to combat this, I overwrote CakeEmail::send() in a custom class CustomEmail (extending CakeEmail) as follows:
public function send($content = null)
{
//get PHP and email timeout values
$phpTimeout = ini_get("max_execution_time");
//if $this->_transportClass is debug, just invoke parent::send() and return
if (!$this->_transportClass instanceof SmtpTransport) {
return parent::send($content);
}
$cfg = $this->_transportClass->config();
$emailTimeout = isset($cfg["timeout"]) && $cfg["timeout"] ? $cfg["timeout"] : 30;
//if PHP max execution time is set (and isn't 0), set it to the email timeout plus 1 second; this should mean the SMTP server should always time out before PHP does
if ($phpTimeout) {
set_time_limit($emailTimeout + 1);
}
//send email
$send = parent::send($content);
//reset PHP timeout to previous value
set_time_limit($phpTimeout);
return $send;
}
However, this isn't alwayus successful and I have had a few instances of this:
Fatal Error: Maximum execution time of 31 seconds exceeded in [C:\path\app\Vendor\pear-pear.cakephp.org\CakePHP\Cake\Network\CakeSocket.php, line 303]
CakeSocket.php line 303 is the $buffer = fread()... line from this CakeSocket::read():
public function read($length = 1024) {
if (!$this->connected) {
if (!$this->connect()) {
return false;
}
}
if (!feof($this->connection)) {
$buffer = fread($this->connection, $length);
$info = stream_get_meta_data($this->connection);
if ($info['timed_out']) {
$this->setLastError(E_WARNING, __d('cake_dev', 'Connection timed out'));
return false;
}
return $buffer;
}
return false;
}
Any ideas?

Answer 1

The problem lies here:
//if PHP max execution time is set (and isn't 0), set it to the email timeout plus 1 second; this should mean the SMTP server should always time out before PHP does
if ($phpTimeout) {
set_time_limit($emailTimeout + 1);
}
In some places in my code I was increasing max time out to more than 30 seconds, but the email timeout was still only 30. This code reverted the PHP timeout to 31 seconds, and I'm guessing other stuff was happening before the email started to send which caused issues.
Fixed code:
//if PHP max execution time is set (and isn't 0), set it to the email timeout plus 1 second; this should mean the SMTP server should always time out before PHP does
if ($phpTimeout && $phpTimeout <= $emailTimeout) {
set_time_limit($emailTimeout + 1);
}