The pulsar client connects to the pulsar broker occasionally successfully and occasionally fails.

[407205745]

Version

Java Client(3.0.0)-->broker(3.0.0)
Broker instance OS: Amazon Linux 2023
Java App running OS : RHEL or Ubuntu or Win 10

Minimal reproduce step
client = PulsarClient.builder()
.serviceUrl("pulsar://10.4.80.27:6650, 10.4.80.28:6650, 10.4.80.29:6650")
.build();

What did you expect to see?
Every client request is sent successfully

What did you see instead?
serviceUrl('pulsar://10.4.80.27:6650, 10.4.80.28:6650, 10.4.80.29:6650'), why is there a connection to hostname:6650

Detailed log
[[id: 0x06d8f469, L:/10.4.175.11:59380 - R:/10.4.80.27:6650]] Connected to server
Starting Pulsar producer perf with config: {"topicName":"persistent://MsgTenant/MsgNamespace/MsgTopic","producerName":null,"sendTimeoutMs":10000,"blockIfQueueFull":false,"maxPendingMessages":0,"maxPendingMessagesAcrossPartitions":0,"messageRoutingMode":"RoundRobinPartition","hashingScheme":"JavaStringHash","cryptoFailureAction":"FAIL","batchingMaxPublishDelayMicros":1000,"batchingPartitionSwitchFrequencyByPublishDelay":10,"batchingMaxMessages":1000,"batchingMaxBytes":131072,"batchingEnabled":true,"chunkingEnabled":false,"chunkMaxMessageSize":-1,"compressionType":"NONE","initialSequenceId":null,"autoUpdatePartitions":true,"autoUpdatePartitionsIntervalSeconds":60,"multiSchema":true,"accessMode":"Shared","lazyStartPartitionedProducers":false,"properties":{},"initialSubscriptionName":null}

Pulsar client config: {"serviceUrl":"pulsar://10.4.80.27:6650,10.4.80.28:6650,10.4.80.29:6650","authPluginClassName":null,"authParams":null,"authParamMap":null,"operationTimeoutMs":30000,"lookupTimeoutMs":30000,"statsIntervalSeconds":60,"numIoThreads":1,"numListenerThreads":1,"connectionsPerBroker":1,"connectionMaxIdleSeconds":180,"useTcpNoDelay":true,"useTls":false,"tlsKeyFilePath":null,"tlsCertificateFilePath":null,"tlsTrustCertsFilePath":null,"tlsAllowInsecureConnection":false,"tlsHostnameVerificationEnable":false,"concurrentLookupRequest":5000,"maxLookupRequest":50000,"maxLookupRedirects":20,"maxNumberOfRejectedRequestPerConnection":50,"keepAliveIntervalSeconds":30,"connectionTimeoutMs":10000,"requestTimeoutMs":60000,"initialBackoffIntervalNanos":100000000,"maxBackoffIntervalNanos":60000000000,"enableBusyWait":false,"listenerName":null,"useKeyStoreTls":false,"sslProvider":null,"tlsKeyStoreType":"JKS","tlsKeyStorePath":null,"tlsKeyStorePassword":null,"tlsTrustStoreType":"JKS","tlsTrustStorePath":null,"tlsTrustStorePassword":null,"tlsCiphers":[],"tlsProtocols":[],"memoryLimitBytes":67108864,"proxyServiceUrl":null,"proxyProtocol":null,"enableTransaction":false,"dnsLookupBindAddress":null,"dnsLookupBindPort":0,"socks5ProxyAddress":null,"socks5ProxyUsername":null,"socks5ProxyPassword":null}

[[id: 0xb893f825, L:/10.4.175.11:59381 - R:/10.4.80.28:6650]] Connected to server
Failed to open connection to tlcb:6650 : java.net.UnknownHostException: Failed to resolve 'tlcb'
[persistent://MsgTenant/MsgNamespace/MsgTopic-partition-0] [null] Error connecting to broker: org.apache.pulsar.client.api.PulsarClientException: java.util.concurrent.CompletionException: java.net.UnknownHostException: Failed to resolve 'tlcb'

[persistent://MsgTenant/MsgNamespace/MsgTopic-partition-0] [null] Could not get connection to broker: org.apache.pulsar.client.api.PulsarClientException: java.util.concurrent.CompletionException: java.net.UnknownHostException: Failed to resolve 'tlcb' -- Will try again in 0.1 s

[persistent://MsgTenant/MsgNamespace/MsgTopic-partition-0] [null] Reconnecting after connection was closed
[[id: 0x9ed872c3, L:/10.4.175.11:59385 - R:/10.4.80.29:6650]] Connected to server
Failed to open connection to tlcb:6650 : java.net.UnknownHostException: Failed to resolve 'tlcb'