No relevant exception/info is provided if leader is unreachable except AskTimeOutException

There is not relevant exception is provided to the applications, if a new datastore request is made for read/write data, while leader is unreachable and re-election has not triggered yet.
This could cause in data loss in some scenarios such as topology manager trying to write link information, but could not because leader was unreachable. Only AskTimeOutException will be thrown, which does not give any relevant information on which applications can act upon.