Optional regular expression (or string in trivial case) with name(s) of node(s) whose being online blocks the current node from starting.

To properly take advantage of this, be sure to set low idleDelay timeout values for those other workers that no longer have work pending.

Note that conflict is evaluated one way ("should this node start if inDemandDelay has elapsed?"), so all nodes in question should declare each other as conflicting -- e.g. by copying the regular expression, if such node names follow the same pattern. In any case, a node would not conflict with itself even if there is a match.

As with other regular expressions, "negative look-ahead" can be used to exclude certain results from the following matching pattern, e.g.:

^(?!myServer$)(.*erver.*)$

This setting allows a Jenkins deployment to co-locate various pre-defined or otherwise provisioned build environments without overwhelming their host -- and instead permits round-robining, one by one.