Infinite loop if sending emails fails

[reverendus7]

Steps to reproduce

1. Misconfigure your mail server
2. Do some folder/file sharing (in order to accumulate emails to send)
3. Launch the script for flushing emails

Expected behaviour

There should not be infinite tries in re-sending failed emails.

Actual behaviour

The infinite loop in trying to send emails is making log file huge. Using a cron for sending emails makes it even worse. It also has impact on cpu usage since the script never ends (and new scripts are launched every-time the cron requires).

Server configuration

ownCloud version: 2.7.2

No errors have been found.

Logs

ownCloud log (data/owncloud.log)

{"reqId":"***","level":3,"time":"2024-03-13T09:45:49+00:00","remoteAddr":"","user":"--","app":"no app in context","method":"--","url":"--","message":"Caused by: {\"Exception\":\"Swift_IoException\",\"Message\":\"Connection to tcp:\\\/\\\/****:25 Timed Out\",\"Code\":0,\"Trace\":\"#0 \\\/var\\\/www\\\/owncloud\\\/lib\\\/composer\\\/swiftmailer\\\/swiftmailer\\\/lib\\\/classes\\\/Swift\\\/Transport\\\/AbstractSmtpTransport.php(469): Swift_Transport_StreamBuffer->readLine()\\n#1 \\\/var\\\/www\\\/owncloud\\\/lib\\\/composer\\\/swiftmailer\\\/swiftmailer\\\/lib\\\/classes\\\/Swift\\\/Transport\\\/AbstractSmtpTransport.php(342): Swift_Transport_AbstractSmtpTransport->getFullResponse()\\n#2 \\\/var\\\/www\\\/owncloud\\\/lib\\\/composer\\\/swiftmailer\\\/swiftmailer\\\/lib\\\/classes\\\/Swift\\\/Transport\\\/EsmtpTransport.php(305): Swift_Transport_AbstractSmtpTransport->executeCommand()\\n#3 \\\/var\\\/www\\\/owncloud\\\/lib\\\/composer\\\/swiftmailer\\\/swiftmailer\\\/lib\\\/classes\\\/Swift\\\/Transport\\\/AbstractSmtpTransport.php(392): Swift_Transport_EsmtpTransport->executeCommand()\\n#4 \\\/var\\\/www\\\/owncloud\\\/lib\\\/composer\\\/swiftmailer\\\/swiftmailer\\\/lib\\\/classes\\\/Swift\\\/Transport\\\/AbstractSmtpTransport.php(499): Swift_Transport_AbstractSmtpTransport->doDataCommand()\\n#5 \\\/var\\\/www\\\/owncloud\\\/lib\\\/composer\\\/swiftmailer\\\/swiftmailer\\\/lib\\\/classes\\\/Swift\\\/Transport\\\/AbstractSmtpTransport.php(518): Swift_Transport_AbstractSmtpTransport->doMailTransaction()\\n#6 \\\/var\\\/www\\\/owncloud\\\/lib\\\/composer\\\/swiftmailer\\\/swiftmailer\\\/lib\\\/classes\\\/Swift\\\/Transport\\\/AbstractSmtpTransport.php(206): Swift_Transport_AbstractSmtpTransport->sendTo()\\n#7 \\\/var\\\/www\\\/owncloud\\\/lib\\\/private\\\/Mail\\\/Mailer.php(103): Swift_Transport_AbstractSmtpTransport->send()\\n#8 \\\/mnt\\\/data\\\/owncloud_data\\\/apps-external\\\/activity\\\/lib\\\/MailQueueHandler.php(305): OC\\\\Mail\\\\Mailer->send()\\n#9 \\\/mnt\\\/data\\\/owncloud_data\\\/apps-external\\\/activity\\\/lib\\\/MailQueueHandler.php(392): OCA\\\\Activity\\\\MailQueueHandler->sendMail()\\n#10 \\\/mnt\\\/data\\\/owncloud_data\\\/apps-external\\\/activity\\\/lib\\\/Command\\\/SendEmails.php(133): OCA\\\\Activity\\\\MailQueueHandler->sendAllEmailsToUser()\\n#11 \\\/mnt\\\/data\\\/owncloud_data\\\/apps-external\\\/activity\\\/lib\\\/Command\\\/SendEmails.php(90): OCA\\\\Activity\\\\Command\\\\SendEmails->sendBatch()\\n#12 \\\/var\\\/www\\\/owncloud\\\/lib\\\/composer\\\/symfony\\\/console\\\/Command\\\/Command.php(255): OCA\\\\Activity\\\\Command\\\\SendEmails->execute()\\n#13 \\\/var\\\/www\\\/owncloud\\\/lib\\\/composer\\\/symfony\\\/console\\\/Application.php(1021): Symfony\\\\Component\\\\Console\\\\Command\\\\Command->run()\\n#14 \\\/var\\\/www\\\/owncloud\\\/lib\\\/composer\\\/symfony\\\/console\\\/Application.php(275): Symfony\\\\Component\\\\Console\\\\Application->doRunCommand()\\n#15 \\\/var\\\/www\\\/owncloud\\\/lib\\\/composer\\\/symfony\\\/console\\\/Application.php(149): Symfony\\\\Component\\\\Console\\\\Application->doRun()\\n#16 \\\/var\\\/www\\\/owncloud\\\/lib\\\/private\\\/Console\\\/Application.php(165): Symfony\\\\Component\\\\Console\\\\Application->run()\\n#17 \\\/var\\\/www\\\/owncloud\\\/console.php(116): OC\\\\Console\\\\Application->run()\\n#18 \\\/var\\\/www\\\/owncloud\\\/occ(11): require_once('\\\/var\\\/www\\\/ownclo...')\\n#19 {main}\",\"File\":\"\\\/var\\\/www\\\/owncloud\\\/lib\\\/composer\\\/swiftmailer\\\/swiftmailer\\\/lib\\\/classes\\\/Swift\\\/Transport\\\/StreamBuffer.php\",\"Line\":166}"}
{"reqId":"NP6AYAouxlR1NcfRJb7g","level":2,"time":"2024-03-13T09:45:52+00:00","remoteAddr":"","user":"--","app":"activity","method":"--","url":"--","message":"Couldn't send notification email to user ***** (Connection to tcp:\/\/*****:25 Timed Out})"}

[reverendus7]

as a quick temporary fix, we modified the SendEmails.php file, in the execute method like this:

        //do {
            $users = $this->mqHandler->getAllUsers(self::BATCH_SIZE);
            $batchCount = \count($users);
            if ($batchCount === 0) {
                // queue is empty
                //break;
                return 0;
            }

            $this->sendBatch($users, $output);
            if ($progress !== null) {
                $progress->advance($batchCount);
            }
        //} while ($batchCount > 0);

In this way, we try to send emails only once per cron run