Thanks for your answer I just tried and on both server but with no luck, here the result :
administrator@logsrv01:~$ sudo apt-get clean
administrator@logsrv01:~$ sudo apt-get update && sudo apt-get upgrade
Get:1 Index of /ubuntu bionic-security InRelease [88.7 kB]
Hit:2 Index of /ubuntu bionic InRelease
Get:3 Index of /ubuntu bionic-updates InRelease [88.7 kB]
Get:4 Index of /infra/ubuntu/ bionic-infra-security InRelease [7,458 B]
Get:5 Index of /infra/ubuntu/ bionic-infra-updates InRelease [7,457 B]
Get:6 Index of /ubuntu bionic-backports InRelease [74.6 kB]
Get:7 Index of /ubuntu bionic-updates/main amd64 Packages [2,414 kB]
Get:8 Index of /ubuntu bionic-updates/main i386 Packages [1,417 kB]
Get:9 Index of /ubuntu bionic-updates/universe amd64 Packages [1,786 kB]
Get:10 Index of /ubuntu bionic-updates/universe i386 Packages [1,599 kB]
Fetched 7,484 kB in 2s (3,086 kB/s)
Reading package lists… Done
Reading package lists… Done
Building dependency tree
Reading state information… Done
Calculating upgrade… Done
Ubuntu comes with ABSOLUTELY NO WARRANTY, to the extent permitted by
applicable law.
The following packages have been kept back:
linux-generic linux-headers-generic linux-image-generic snapd 0 upgraded, 0 newly installed, 0 to remove and 4 not upgraded.
administrator@logsrv01:~$ sudo apt install graylog-server
Reading package lists… Done
Building dependency tree
Reading state information… Done graylog-server is already the newest version (4.2.1-1).
0 upgraded, 0 newly installed, 0 to remove and 4 not upgraded.
I’m curious about this statement specially the part 4 not upgrade.
Let me add to this that sudo apt-get upgrade will finish with Reading state information… Done 0 upgraded, 0 newly installed, 0 to remove and 4 not upgraded if you already have installed all latest updates. When you already have installed all updates for your system, sudo apt-get upgrade will not reinstall stuff. If you get a message along the lines of x packages have been kept back, you should
run
sudo apt-get dist-upgrade
See if that works.
By chance did you try to restart Graylog-server service?
This seams like something is wrong with the repo, by chance do you have Graylog pinned or something?
Do you see the new version of graylog in your repo?
Perhaps this may help
The links you provided definitely lead me in the right direction.
Opened /etc/apt/sources.list.d/graylog.list and noticed that the entry was commented out on both servers which is definitely odd.
Anyhow removed the # and voila:
administrator@m2malogsrv01:~$ dpkg -l | grep -E “.(graylog).”
ic graylog-2.5-repository 1-1 all Package to install Graylog 2.5 GPG key and repository
ii graylog-4.2-repository 1-4 all Package to install Graylog 4.2 GPG key and repository
ii graylog-server 4.2.6-1 all Graylog server