The issue has been resolved.

The root cause of the previous issues has been identified as a failing boot SSD and an replacement disk has been ordered. Server will be taken down immediately to clone the disk and migrate as quickly as possible

The fix has been applied and the services are being restored gradually.

Istanbul server is down due to (what I though was a) networking configuration mistake(which was not, it simply didn't turn back on after rebooting due to failing disk) and we are working to resolve the issue.