You cannot get streamer instance on node which does not have this particular streamer configured. However, you can easily achieve your requirement by providing GridStreamerEventRouter that will not route events on nodes which are not supposed to participate in event processing.
For example, you can use random event router with predicate which will filter nodes by user attribute (you can set user attributes for a node with GridConfiguration.setUserAttributes(...)):
GridStreamerConfiguration streamCfg = new GridStreamerConfiguration();
//...
streamCfg.setRouter(new GridStreamerRandomEventRouter(new GridPredicate<GridNode>() {
@Override public boolean apply(GridNode node) {
return !"CLIENT".equals(node.attribute("STREAMER_ROLE"));
}
}));