Ubuntu - install multithreading php

[thevento]

Hi, i try to install a packet which allows use multithreading in php.
System: Ubuntu 17.10
I do it in this way:

sudo add-apt-repository ppa:ondrej/php-zts

Everything seems correct
Then:

sudo apt update

Result:

Hit:1 http://pl.archive.ubuntu.com/ubuntu artful InRelease
Hit:2 http://pl.archive.ubuntu.com/ubuntu artful-updates InRelease                                                  
Get:3 http://security.ubuntu.com/ubuntu artful-security InRelease [78.6 kB]                                         
Ign:4 http://dl.google.com/linux/chrome/deb stable InRelease                                                        
Hit:5 http://ppa.launchpad.net/ondrej/apache2/ubuntu artful InRelease                                               
Hit:6 http://pl.archive.ubuntu.com/ubuntu artful-backports InRelease                                                
Hit:7 http://dl.google.com/linux/chrome/deb stable Release                                                          
Ign:8 http://ppa.launchpad.net/ondrej/php-zts/ubuntu artful InRelease                                               
Err:9 http://ppa.launchpad.net/ondrej/php-zts/ubuntu artful Release                                             
  404  Not Found
Reading package lists... Done                      
E: The repository 'http://ppa.launchpad.net/ondrej/php-zts/ubuntu artful Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

It's looks like packet does not exist and i get 404 error, i don't know how i fix that..


Thank you in advance for your help..

[SeijiSensei]

How busy is your web server? I highly doubt you're pushing it to levels where multi-threaded PHP might actually make an observable difference in performance. Inefficient coding and poorly-indexed databases are the more likely culprits.

[thevento]

It's not important, I want only to run cleary (with index file only) project and test multi-threaded, nothing more... I don't think so this information is important but i use apache2...