Just a quick PSA to let everyone know that vRNI 3.8 Patch 4 (201808101430) is now available for download. If you are running vRNI 3.8 with NSX, be sure to patch as soon as possible or disable controller polling based on instructions in the workaround section of KB 57311.
Some changes were made in vRNI 3.8 for NSX controller polling. It now uses both the NSX Central CLI as well as SSH sessions to obtain statistics and information. In some situations, excessive numbers of SSH sessions are left open and memory exhaustion on controller nodes can occur.
If you do find a controller in this state, a reboot will get it back to normal again. Just be sure to keep a close eye on your control cluster. If two or three go down, you’ll lose controller majority and will likely run into control plane and data plane problems for VMs on logical switches or VMs using DLR routing.