Failed to send Message to remote node in ignite - ignite

Question

I am running my service in local environment and trying to connect to remote node but it showing error failed to send message to remote node.
I want to run my service in local environment and connect it to remote ignite node on different server.
my configuration is:
IgniteConfiguration igniteConfig = new IgniteConfiguration();
igniteConfig.setIgniteInstanceName("MasterCacheCluster");
igniteConfig.setPeerClassLoadingEnabled(true);
igniteConfig.setClientMode(true);
TcpDiscoverySpi discoverySpi = new TcpDiscoverySpi();
TcpDiscoveryVmIpFinder ipFinder = new
TcpDiscoveryVmIpFinder();
TcpCommunicationSpi communicationSpi = new
TcpCommunicationSpi();
ipFinder.setAddresses(Arrays.asList("server_address":47500..47509"));
discoverySpi.setIpFinder(ipFinder);
igniteConfig.setDiscoverySpi(discoverySpi);
DataStorageConfiguration dataCfg = new
DataStorageConfiguration();
DataRegionConfiguration rgnCfg = new
DataRegionConfiguration();
rgnCfg.setName("Sample_Cluster_Region");
rgnCfg.setPageEvictionMode(DataPageEvictionMode.RANDOM_2_LRU);
rgnCfg.setPersistenceEnabled(true);
rgnCfg.setMetricsEnabled(true);
dataCfg.setDataRegionConfigurations(rgnCfg);
Ignite ignite = Ignition.start(igniteConfig);
ignite.cluster().active(true);
System.out.println("Cluster Size: " +
ignite.cluster().nodes().size());
return ignite;
** server address is hidden due to privacy reason
[13:12:18,839][SEVERE][exchange-worker-#62%MasterCacheCluster%][TcpCommunicationSpi] Failed to send message to remote node [node=TcpDiscoveryNode [id=724fff2c-76c2-44e7-921f-b7c37dac7d15, consistentId=7c4ed309-0b9b-40ba-84a1-90384e0940ea, addrs=ArrayList [0:0:0:0:0:0:0:1%lo, 10.3.0.8, 127.0.0.1], sockAddrs=null, discPort=47500, order=1, intOrder=1, lastExchangeTime=1676878928401, loc=false, ver=2.14.0#20220929-sha1:951e8deb, isClient=false], msg=GridIoMessage [plc=2, topic=TOPIC_CACHE, topicOrd=8, ordered=false, timeout=0, skipOnTimeout=false, msg=GridDhtPartitionsSingleMessage [parts=null, partCntrs=null, partsSizes=null, partHistCntrs=null, err=null, client=true, exchangeStartTime=1676878928573, finishMsg=null, super=GridDhtPartitionsAbstractMessage [exchId=GridDhtPartitionExchangeId [topVer=AffinityTopologyVersion [topVer=2, minorTopVer=0], discoEvt=DiscoveryEvent [evtNode=TcpDiscoveryNode [id=96f70bd7-cbfb-4a3e-900d-00a93b10d892, consistentId=96f70bd7-cbfb-4a3e-900d-00a93b10d892, addrs=ArrayList [0:0:0:0:0:0:0:1, 127.0.0.1, 172.16.16.50], sockAddrs=HashSet [/[0:0:0:0:0:0:0:1]:0, /127.0.0.1:0, LAPTOP-6AUCFF2I/172.16.16.50:0], discPort=0, order=2, intOrder=0, lastExchangeTime=1676878923997, loc=true, ver=2.14.0#20220929-sha1:951e8deb, isClient=true], topVer=2, msgTemplate=null, span=org.apache.ignite.internal.processors.tracing.NoopSpan#baed14f, nodeId8=96f70bd7, msg=null, type=NODE_JOINED, tstamp=1676878928556], nodeId=96f70bd7, evt=NODE_JOINED], lastVer=GridCacheVersion [topVer=0, order=1676878923547, nodeOrder=0, dataCenterId=0], super=GridCacheMessage [msgId=1, depInfo=null, lastAffChangedTopVer=AffinityTopologyVersion [topVer=-1, minorTopVer=0], err=null, skipPrepare=false]]]]]
class org.apache.ignite.IgniteCheckedException: Failed to connect to node (is node still alive?). Make sure that each ComputeTask and cache Transaction has a timeout set in order to prevent parties from waiting forever in case of network issues [nodeId=724fff2c-76c2-44e7-921f-b7c37dac7d15, addrs=[/10.3.0.8:47100, /[0:0:0:0:0:0:0:1%lo]:47100, /127.0.0.1:47100]]

Answer 1

Your client tries to establish communication link to the server node with id=724fff2c-76c2-44e7-921f-b7c37dac7d15 after receiving it's address through discovery protocol. This exception basically implies that there's no connectivity between your local host and "server_address":47100. Every single node (including clients) should be visible to the rest of a cluster. My guess is you have some firewall rules or something like that.
Try running some tools to troubleshoot, you could start with.
nc -vz "server_address" 47100
It should be run from your laptop.
It's also worth mentioning that your server expose ipv6 addresses. It's recommended to use ipv4 at the moment. Add -Djava.net.preferIPv4Stack=true JVM param to the both client and server JVM start scripts.