question: public void addSubscription ( String subscriptionChannel , int streamId , FragmentHandler fragmentHandler ) { if ( ! hasSubscriptionForChannel ( subscriptionChannel ) ) { debug ( "Creating a subscriptions to channel => {}" , subscriptionChannel ) ; Subscription subscription = aeron . addSubscription ( subscriptionChannel , streamId ) ; debug ( "Subscription created channel => {} " , subscriptionChannel ) ; SubscriptionGroup subscriptionGroup = new SubscriptionGroup ( subscriptionChannel , subscription , fragmentHandler ) ; subscriptionGroups . add ( subscriptionGroup ) ; debug ( "Subscriptions created to channel => {}" , subscriptionChannel ) ; } else { debug ( "Subscription already exists for channel => {}" , subscriptionChannel ) ; } }
target:  Adds an Aeron subscription to be polled. This method will create a subscription for each of the polling threads.