About the SubscriptionRequestTypeFactory.UNSUBSCRIBE

[eric]

I set up a data subscribe as below

..........................

mdr.setSubscriptionRequestType(SubscriptionRequestTypeFactory.SUBSCRIBE);

IMessage msg = mdr.toMessage(userSessionHistory.getSessionID(),ConnectionManagerEx.getMessageFactory());
String status = userSessionHistory.send(msg);

..........................

But sometimes, I want to get some historical data, so have to UNSUBSCRIBE it firstly.

But when I set up

mdr.setSubscriptionRequestType(SubscriptionRequestTypeFactory.SUBSCRIBE);

it seems does not work well, sometimes the data still pop up.Why?

Or Is it possible to close/kill a mdr (MarketDataRequest)?

Help me, please

Thanks