This value reports the memory-usage threshold, in bytes, at which the node's storage management begins to consider its resources constrained, serving as an early warning line before things become critical. Administrators use it as a reference point to know when the currently-used memory value has crossed into a state that may soon require attention. For example, if the memory-used value exceeds this warning threshold, an admin might proactively investigate what is consuming APPN memory before it worsens.