PHP throwing server errors after Ubuntu ran an unattended-upgrades session - any way to determine the cause?

Solution 1:

We saw this hit our environment and it happened again 5 hours later. Considering rolling back to an older version of libc6 patch.

Here is the Ubuntu bug for this issue that confirms what we're all seeing: https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/1674532

Update: the issue has since been fixed.

See comments #16, #17 and #18 in the above report. Updating libc should resolve the issue. A reboot is recommended to make sure that any running processes that are running during the update that make use of this library keep functioning the way they should.