Stokes and Newton will be taken down per our bi-annual routine maintenance cycle during mid-May. Specifically, the clusters will be unavailable from the morning of Saturday, May 19 through the morning of Monday, May 28.
The primary objective during this downtime is to upgrade the underlying operating systems of the cluster to CentOS 7.4. There will also be some changes made to the R installs to bring more consistency across versions. We will provide more detail in the change log when we bring the system back online.
Recall that we now routinely bring the system down twice a year, once in late Fall and once in late Spring. We will keep the users notified in advance of such downtimes, but we recommend you build such expectations into your workflow. Though we anticipate no data loss during this time, it's never a bad idea to backup your materials. So we suggest you use this opportunity to copy salient data and code off of Stokes prior to the downtime.