Hazelcast: connecting to remote cluster

Question

We have a cluster of Hazelcast nodes all running on one remote system (single physical system with many nodes). We would like to connect to this cluster from an external client - a Java application which uses code as below to connect to Hazelcast:

        ClientConfig clientConfig = new ClientConfig();
        clientConfig.addAddress(config.getHost() + ":" + config.getPort());

        client = HazelcastClient.newHazelcastClient(clientConfig);

where, host is the IP of remote and port is 5701.

This still connects to the local host (127.0.0.1). What am I missing?

Edit:

If the java client is the only hazelcast app running on the local system, it fails to connect and throws the exception: java.lang.IllegalStateException: Cannot get initial partitions!

From the logs:

14:58:26.717 [main] INFO c.m.b.p.s.s.HazelcastCacheClient - creating new Hazelcast instance

14:58:26.748 [main] INFO com.hazelcast.core.LifecycleService - HazelcastClient[hz.client_0_dev][3.2.1] is STARTING

14:58:27.029 [main] INFO com.hazelcast.core.LifecycleService - HazelcastClient[hz.client_0_dev][3.2.1] is STARTED

14:58:27.061 [hz.client_0_dev.cluster-listener] INFO com.hazelcast.core.LifecycleService - HazelcastClient[hz.client_0_dev][3.2.1] is CLIENT_CONNECTED

14:58:27.061 [hz.client_0_dev.cluster-listener] INFO c.h.client.spi.ClientClusterService -

Members [5] { Member [127.0.0.1]:5701 Member [127.0.0.1]:5702 Member [127.0.0.1]:5703 Member [127.0.0.1]:5704 Member [127.0.0.1]:5705 }

14:58:47.278 [main] ERROR c.h.c.spi.ClientPartitionService - Error while fetching cluster partition table!

com.hazelcast.spi.exception.RetryableIOException: java.util.concurrent.ExecutionException: com.hazelcast.core.HazelcastException: java.net.ConnectException: Connection refused: no further information ... Caused by: java.util.concurrent.ExecutionException: com.hazelcast.core.HazelcastException: java.net.ConnectException: Connection refused: no further information

at java.util.concurrent.FutureTask.report(Unknown Source) ~[na:1.8.0_31]

at java.util.concurrent.FutureTask.get(Unknown Source) ~[na:1.8.0_31]

at com.hazelcast.client.connection.nio.ClientConnectionManagerImpl.getOrConnect(ClientConnectionManagerImpl.java:282) ~[BRBASE-service-manager-1.0.0-jar-with-dependencies.jar:na]

... 14 common frames omitted

Caused by: com.hazelcast.core.HazelcastException: java.net.ConnectException: Connection refused: no further information

at com.hazelcast.util.ExceptionUtil.rethrow(ExceptionUtil.java:45) ~[BRBASE-service-manager-1.0.0-jar-with-dependencies.jar:na] ...

Barrington

Please share your Config file – Tardif

There is no config file. The config here is an internal class. The host and port are passed as command line arguments to the java client. – Barrington

did you try harcoding the address.? does it still connect to the local host.? – Tardif

If client's application is started first, it always fails. – Tardif

Server is already running. Client is started next. – Barrington

Answer 1

To connect to the remote cluster, make sure the cluster uses the external IP and not 127.0.0.1. In our case we have a single physical system, with multiple nodes, with tcp-ip mode enabled. The hazelcast.xml has the configuration:

<tcp-ip enabled="true">
    <!-- This should be external IP -->
    <interface>172.x.x.x</interface>
</tcp-ip>

Barrington

Answer 2

Can you try:

ClientConfig config = new ClientConfig();
config.getNetworkConfig().addAddress(host + ":" + port);
HazelcastInstance instance = HazelcastClient.newHazelcastClient(config);

Naos

this sounds like you have a firewall problem – Naos

All are in one network within the company LAN. I can telnet to the target host-port. – Barrington

That's weird. Can you test a new version like just today released 3.5? Is server and client using the same version? – Naos

What should be settings of the cluster to allow connections from remote? For example, if the remote cluster has tcp-ip enabled with 127.0.0.1 or fixed IPs, will it allow any remote client to connect? Logically, it should not, isn't it? Else it is a security risk. – Barrington

The configured IPs are only used in a comparison on requests, if incoming IP is not matching the pre-configured IP(s) the connection is denied. To prevent listening on other IPs you need to set the property "hazelcast.socket.bind.any" to false. – Naos

Answer 3

If you want to connect to multiple ip's running Hazelcast as cluster add below to your client config and then instantiate client.

//configure client properties
ClientConfig config = new ClientConfig();
String[] addresses = {"172.20.250.118" + ":" + "5701","172.20.250.49" + ":" + "5701"};
config.getNetworkConfig().addAddress(addresses);

//start Hazelcast client
HazelcastInstance hazelcastInstance = HazelcastClient.newHazelcastClient(config);

Armoured