plugin is still booting up and CO invoked a non-probe func before Probe returned OK.
plugin is overwhelmed with requests and cannot process further requests until it catches up
plugin is encountering transient network error conditions when communicating w/ the storage backend (e.g. read/write timeouts), and/or storage backend has indicated "too many requests" (so the plugin should try to shed load).
In response to receiving this error code a CO can choose to:
Some use cases:
In response to receiving this error code a CO can choose to: