Got the following from the IT team .... I reckoned it's about 400 nodes that were affected ...
---------- Forwarded message ----------
Subject: RE: Scheduled Maintenance of Servers
Please be informed that HPC CLUSTERS of X, Y, Z are not accessible due to unforeseen power failure in the annual Power Test (FPT) of Data center.
Apologies for the inconvenience caused.
Thank you for your understanding and cooperation.
Please do revert us should you have queries.