CODEWITHSUNDEEP
hazelcast
Robert Simmons Jr.
Robert Simmons Jr.

Reputation: 1182

Hazelcast IMap Entry that goes away when a node is removed?

I have been searching for a means to record some data in a Hazelcast map and then have that data removed when the node goes away. The idea is that this data is something like an address book to certain processes and I only want the addresses of processes running on live nodes so I can avoid pushing data to dead node processes. Is there any way this can easily be done in hazelcast or would i need some sort of custom solution such as a Member listener?

Thanks in advance.

Upvotes: 2

Views: 73

Answers (1)

Wim Deblauwe
Wim Deblauwe

Reputation: 26858

A MembershipListener would be the way to do it. For example:

public class Test
{
    public static void main( String[] args )
    {
        HazelcastInstance hazelcastInstance = Hazelcast.newHazelcastInstance();

        IMap<Object, Object> bookkeeping = hazelcastInstance.getMap( "bookkeeping" );

        hazelcastInstance.getCluster().addMembershipListener( new MembershipListener()
        {
            @Override
            public void memberAdded( MembershipEvent membershipEvent )
            {
                bookkeeping.put( membershipEvent.getMember().getUuid(), true );
            }

            @Override
            public void memberRemoved( MembershipEvent membershipEvent )
            {
                bookkeeping.put( membershipEvent.getMember().getUuid(), false );
            }

            @Override
            public void memberAttributeChanged( MemberAttributeEvent memberAttributeEvent )
            {

            }
        } );
    }
}

Upvotes: 1

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