Package org.apache.pulsar.broker.service

Class AbstractDispatcherMultipleConsumers

    • Field Detail

      • consumerList

        protected final java.util.concurrent.CopyOnWriteArrayList<Consumer> consumerList

      • consumerSet

        protected final com.carrotsearch.hppc.ObjectSet<Consumer> consumerSet

      • currentConsumerRoundRobinIndex

        protected volatile int currentConsumerRoundRobinIndex

    • Constructor Detail

      • AbstractDispatcherMultipleConsumers

        protected AbstractDispatcherMultipleConsumers​(Subscription subscription,
                                              org.apache.pulsar.broker.ServiceConfiguration serviceConfig)

    • Method Detail

      • isConsumerConnected

        public boolean isConsumerConnected()

      • getConsumers

        public java.util.concurrent.CopyOnWriteArrayList<Consumer> getConsumers()

      • canUnsubscribe

        public boolean canUnsubscribe​(Consumer consumer)

      • isClosed

        public boolean isClosed()

      • getType

        public org.apache.pulsar.common.api.proto.CommandSubscribe.SubType getType()

      • isConsumerAvailable

        public abstract boolean isConsumerAvailable​(Consumer consumer)

      • cancelPendingRead

        protected void cancelPendingRead()

      • getNextConsumer

        public Consumer getNextConsumer()
         Broker gives more priority while dispatching messages. Here, broker follows descending priorities. (eg:
 0=max-priority, 1, 2,..)
 
        
 Broker will first dispatch messages to max priority-level consumers if they
 have permits, else broker will consider next priority level consumers.
 Also on the same priority-level, it selects consumer in round-robin manner.
 
        
 If subscription has consumer-A with  priorityLevel 1 and Consumer-B with priorityLevel 2
 then broker will dispatch
 messages to only consumer-A until it runs out permit and then broker starts dispatching messages to Consumer-B.
 
        
 Consumer PriorityLevel Permits
 C1       0             2
 C2       0             1
 C3       0             1
 C4       1             2
 C5       1             1
 Result of getNextConsumer(): C1, C2, C3, C1, C4, C5, C4
 
         Algorithm:
 1. consumerList: it stores consumers in sorted-list: max-priority stored first
 2. currentConsumerRoundRobinIndex: it always stores last served consumer-index

 Each time getNextConsumer() is called:
        
 1. It always starts to traverse from the max-priority consumer (first element) from sorted-list
 2. Consumers on same priority-level will be treated equally and it tries to pick one of them in
    round-robin manner
 3. If consumer is not available on given priority-level then only it will go to the next lower priority-level
    consumers
 4. Returns null in case it doesn't find any available consumer
        Returns:
        nextAvailableConsumer

      • getRandomConsumer

        public Consumer getRandomConsumer()
        Get random consumer from consumerList.
        Returns:
        null if no consumer available, else return random consumer from consumerList