Как установить pgpool в Ubuntu 18.04 Bionic?

root@db01:~# apt update
Hit:1 http://archive.ubuntu.com/ubuntu bionic InRelease
Hit:2 http://security.ubuntu.com/ubuntu bionic-security InRelease
Hit:3 http://archive.ubuntu.com/ubuntu bionic-updates InRelease
Ign:4 https://apt.datadoghq.com stable InRelease
Hit:5 https://apt.datadoghq.com stable Release
Hit:6 http://archive.ubuntu.com/ubuntu bionic-backports InRelease
Reading package lists... Done
Building dependency tree
Reading state information... Done
24 packages can be upgraded. Run 'apt list --upgradable' to see them.

root@db01:~# apt install pgpool2
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package pgpool2 is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'pgpool2' has no installation candidate

root@db01:~# apt search pgpool
Sorting... Done
Full Text Search... Done