> But when we use TCP it is expected that log messages will not be lost.

I wouldn't go that far: logging is not a primary program function (i.e. the library or application should work exactly the same if logging were to be disabled). For the situation where you absolutely don't want to lose messages (apparently not that common a case - the relevant code is over 15 years old, and I can't remember this coming up before), you could either subclass SocketHandler to buffer messages, or use e.g. a MemoryHandler in conjunction with a SocketHandler.