Plesk Optimization for 504 Gateway Time-out

A website is not accessible with “504 Gateway Time-out”

Log files show:

# tail -n1 /var/log/httpd/error_log
[Tue Sep 04 19:11:38.300358 2018] [mpm_event:error] [pid 1192:tid 139861305055360] AH00484: server reached MaxRequestWorkers setting, consider raising the MaxRequestWorkers setting

[proxy_fcgi:error] [pid 50203:tid 139860761302784] (70007)The timeout specified has expired:

How to Update the Default Plesk SSL (not domain ssl)

You can update the SSL through Plesk under Tools & Settings -> SSL/TLS Certificates.

To change the default Plesk certificate and do not reassign certificates for all domains manually, do the following:

  1. In Plesk open Tools & Settings > SSL/TLS Certificates > Add > proceed with adding new certificate.
  2. Return to Tools & Settings > SSL/TLS Certificates > select the certificate created in previous step > Make Default .

Office 365 Anti-Spam IP Delist Portal

If you’re trying to send mail to an Office 365 recipient and the mail has been rejected because of your sending IP address, follow these steps to submit a delisting request.

Error messages may be similar to the following:

ECDHE-RSA-AES256-SHA384:256 CV=yes: SMTP error from remote mail server after RCPT TO:: 550 5.7.606 Access denied, banned sending IP []. To request removal from this list please visit and follow the directions. For more information please go to (AS16012609) []

Generate ssh keys on linux and use with PuTTY on Windows

Log into the Linux server as the user you are going to use to connect with ssh. Generate the key.

ssh-keygen -t rsa -b 4096 -C ""
Generating public/private rsa key pair.
Enter file in which to save the key (/home/user/.ssh/id_rsa): 
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /home/user/.ssh/id_rsa.
Your public key has been saved in /home/user/.ssh/
The key fingerprint is:
The key's randomart image is:
+---[RSA 4096]----+
|                 |
|               ..|
|              o *|
|           . . E+|
|        S . = =o=|
|         . + * O=|
|          . + @.*|
|            .@ %=|
|            ++@+#|

Now copy the id_rsa key to your Windows desktop. This can be done by copying and pasting the contents of the file or using an SCP client such as PSCP which is supplied with the PuTTY install or FileZilla.

Read moreGenerate ssh keys on linux and use with PuTTY on Windows

Error After Upgrade from PHP 5.4 to 5.6 on CentOS

After an upgrade from PHP 5.4 to 5.6, I received an error when I run an app update:

Your requirements could not be resolved to an installable set of packages.
Problem 1 – This package requires php >=5.6 but your PHP version (5.4.45) does not satisfy that requirement.


The shell cli is currently running on php5.4. You will need to specify what version the shell will use. This can be done by running the following command.

# echo "alias php='/opt/plesk/php/5.6/bin/php'" >> ~/.bashrc

The guide from Plesk

You can confirm here:

# php -v
PHP 5.6.35 (cli) (built: Mar 30 2018 12:52:22)
Copyright (c) 1997-2016 The PHP Group

Disable ONLY_FULL_GROUP_BY in Mysql on Ubuntu 16

Recently I ran a command in mysql that resulted in this error:


So I had to add a line to the mysql config file. In Ubuntu 16:

# nano /etc/mysql/mysql.conf.d/mysqld.cnf

Add the following line under mysqld


Restart mysql:

# systemctl restart mysql