Currently ManagedServer is using blocking calls for suspend() and resume() operantions. Those calls can potentially wait forever for a server response.
This issue has been opened to change them allowing the use of a BlockingQueueOperationListener and prevent that potential situation. Basically it continues the changes already implemented in
WFCORE-1473, but this time applying them for :suspend-servers (without an explicity timeout) and :resume-servers operations in a domain mode.