title: Kafka Confluent error - java.net.BindException: Address already in use
body: <p>I am running Kafka via Confluent platform. I have followed the steps as per mentioned, java.net.BindException: Address already in use</p>
  
  <p>As per documentation here, <a href="https://docs.confluent.io/2.0.0/quickstart.html#quickstart" rel="noreferrer">https://docs.confluent.io/2.0.0/quickstart.html#quickstart</a></p>
  
  <p>start zookeeper, </p>
  
  <pre><code>$ ./bin/zookeeper-server-start ./etc/kafka/zookeeper.properties
  </code></pre>
  
  <p>start kafka,</p>
  
  <pre><code>$ ./bin/kafka-server-start ./etc/kafka/server.properties
  </code></pre>
  
  <p>next when I run <code>schema-registry</code> command,</p>
  
  <pre><code>$ ./bin/schema-registry-start ./etc/schema-registry/schema-registry.properties
  </code></pre>
  
  <p>I have observed error as, <code>java.net.BindException: Address already in use</code></p>
  
  <p>I am running all this locally in a macbook. Could somoene please help me to solve this <code>address already in use</code> error?</p>
  
  <p>Console log:</p>
  
  <pre><code> EFGHS-MER648W:confluent-4.0.0 user$ sudo ./bin/schema-registry-start ./etc/schema-registry/schema-registry.properties
  Password: 
  [2018-01-09 13:09:03,510] INFO SchemaRegistryConfig values: 
      metric.reporters = []
      kafkastore.sasl.kerberos.kinit.cmd = /usr/bin/kinit
      response.mediatype.default = application/vnd.schemaregistry.v1+json
      kafkastore.ssl.trustmanager.algorithm = PKIX
      authentication.realm = 
      ssl.keystore.type = JKS
      kafkastore.topic = _schemas
      metrics.jmx.prefix = kafka.schema.registry
      kafkastore.ssl.enabled.protocols = TLSv1.2,TLSv1.1,TLSv1
      kafkastore.topic.replication.factor = 3
      ssl.truststore.password = [hidden]
      kafkastore.timeout.ms = 500
      host.name = 192.168.0.13
      kafkastore.bootstrap.servers = []
      schema.registry.zk.namespace = schema_registry
      kafkastore.sasl.kerberos.ticket.renew.window.factor = 0.8
      kafkastore.sasl.kerberos.service.name = 
      schema.registry.resource.extension.class = 
      ssl.endpoint.identification.algorithm = 
      compression.enable = false
      kafkastore.ssl.truststore.type = JKS
      avro.compatibility.level = backward
      kafkastore.ssl.protocol = TLS
      kafkastore.ssl.provider = 
      kafkastore.ssl.truststore.location = 
      response.mediatype.preferred = [application/vnd.schemaregistry.v1+json, application/vnd.schemaregistry+json, application/json]
      kafkastore.ssl.keystore.type = JKS
      ssl.truststore.type = JKS
      kafkastore.ssl.truststore.password = [hidden]
      access.control.allow.origin = 
      ssl.truststore.location = 
      ssl.keystore.password = [hidden]
      port = 8081
      kafkastore.ssl.keystore.location = 
      master.eligibility = true
      ssl.client.auth = false
      kafkastore.ssl.keystore.password = [hidden]
      kafkastore.security.protocol = PLAINTEXT
      ssl.trustmanager.algorithm = 
      authentication.method = NONE
      request.logger.name = io.confluent.rest-utils.requests
      ssl.key.password = [hidden]
      kafkastore.zk.session.timeout.ms = 30000
      kafkastore.sasl.mechanism = GSSAPI
      kafkastore.sasl.kerberos.ticket.renew.jitter = 0.05
      kafkastore.ssl.key.password = [hidden]
      zookeeper.set.acl = false
      schema.registry.inter.instance.protocol = http
      authentication.roles = [*]
      metrics.num.samples = 2
      ssl.protocol = TLS
      schema.registry.group.id = schema-registry
      kafkastore.ssl.keymanager.algorithm = SunX509
      kafkastore.connection.url = localhost:2181
      debug = false
      listeners = [http://0.0.0.0:8081]
      kafkastore.group.id = 
      ssl.provider = 
      ssl.enabled.protocols = []
      shutdown.graceful.ms = 1000
      ssl.keystore.location = 
      ssl.cipher.suites = []
      kafkastore.ssl.endpoint.identification.algorithm = 
      kafkastore.ssl.cipher.suites = 
      access.control.allow.methods = 
      kafkastore.sasl.kerberos.min.time.before.relogin = 60000
      ssl.keymanager.algorithm = 
      metrics.sample.window.ms = 30000
      kafkastore.init.timeout.ms = 60000
   (io.confluent.kafka.schemaregistry.rest.SchemaRegistryConfig:175)
  [2018-01-09 13:09:03,749] INFO Logging initialized @629ms (org.eclipse.jetty.util.log:186)
  [2018-01-09 13:09:04,202] INFO Initializing KafkaStore with broker endpoints: PLAINTEXT://192.168.0.13:9092 (io.confluent.kafka.schemaregistry.storage.KafkaStore:103)
  [2018-01-09 13:09:04,475] INFO Validating schemas topic _schemas (io.confluent.kafka.schemaregistry.storage.KafkaStore:228)
  [2018-01-09 13:09:04,482] WARN The replication factor of the schema topic _schemas is less than the desired one of 3. If this is a production environment, it's crucial to add more brokers and increase the replication factor of the topic. (io.confluent.kafka.schemaregistry.storage.KafkaStore:242)
  [2018-01-09 13:09:04,567] INFO Initialized last consumed offset to -1 (io.confluent.kafka.schemaregistry.storage.KafkaStoreReaderThread:138)
  [2018-01-09 13:09:04,567] INFO [kafka-store-reader-thread-_schemas]: Starting (io.confluent.kafka.schemaregistry.storage.KafkaStoreReaderThread:72)
  [2018-01-09 13:09:04,651] INFO Wait to catch up until the offset of the last message at 7 (io.confluent.kafka.schemaregistry.storage.KafkaStore:277)
  [2018-01-09 13:09:04,675] INFO Joining schema registry with Zookeeper-based coordination (io.confluent.kafka.schemaregistry.storage.KafkaSchemaRegistry:210)
  [2018-01-09 13:09:04,682] INFO Created schema registry namespace localhost:2181/schema_registry (io.confluent.kafka.schemaregistry.masterelector.zookeeper.ZookeeperMasterElector:161)
  [2018-01-09 13:09:04,705] INFO Successfully elected the new master: {"host":"192.168.0.13","port":8081,"master_eligibility":true,"scheme":"http","version":1} (io.confluent.kafka.schemaregistry.masterelector.zookeeper.ZookeeperMasterElector:102)
  [2018-01-09 13:09:04,715] INFO Wait to catch up until the offset of the last message at 8 (io.confluent.kafka.schemaregistry.storage.KafkaStore:277)
  [2018-01-09 13:09:04,778] INFO Adding listener: http://0.0.0.0:8081 (io.confluent.rest.Application:182)
  [2018-01-09 13:09:04,844] INFO jetty-9.2.22.v20170606 (org.eclipse.jetty.server.Server:327)
  [2018-01-09 13:09:05,411] INFO HV000001: Hibernate Validator 5.1.3.Final (org.hibernate.validator.internal.util.Version:27)
  [2018-01-09 13:09:05,547] INFO Started o.e.j.s.ServletContextHandler@54c62d71{/,null,AVAILABLE} (org.eclipse.jetty.server.handler.ContextHandler:744)
  [2018-01-09 13:09:05,555] WARN FAILED NetworkTrafficServerConnector@4879dfad{HTTP/1.1}{0.0.0.0:8081}: java.net.BindException: Address already in use (org.eclipse.jetty.util.component.AbstractLifeCycle:212)
  java.net.BindException: Address already in use
      at sun.nio.ch.Net.bind0(Native Method)
      at sun.nio.ch.Net.bind(Net.java:433)
      at sun.nio.ch.Net.bind(Net.java:425)
      at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223)
      at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)
      at org.eclipse.jetty.server.ServerConnector.open(ServerConnector.java:321)
      at org.eclipse.jetty.server.AbstractNetworkConnector.doStart(AbstractNetworkConnector.java:80)
      at org.eclipse.jetty.server.ServerConnector.doStart(ServerConnector.java:236)
      at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
      at org.eclipse.jetty.server.Server.doStart(Server.java:366)
      at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
      at io.confluent.kafka.schemaregistry.rest.SchemaRegistryMain.main(SchemaRegistryMain.java:44)
  [2018-01-09 13:09:05,557] WARN FAILED io.confluent.rest.Application$1@388526fb: java.net.BindException: Address already in use (org.eclipse.jetty.util.component.AbstractLifeCycle:212)
  java.net.BindException: Address already in use
      at sun.nio.ch.Net.bind0(Native Method)
      at sun.nio.ch.Net.bind(Net.java:433)
      at sun.nio.ch.Net.bind(Net.java:425)
      at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223)
      at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)
      at org.eclipse.jetty.server.ServerConnector.open(ServerConnector.java:321)
      at org.eclipse.jetty.server.AbstractNetworkConnector.doStart(AbstractNetworkConnector.java:80)
      at org.eclipse.jetty.server.ServerConnector.doStart(ServerConnector.java:236)
      at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
      at org.eclipse.jetty.server.Server.doStart(Server.java:366)
      at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
      at io.confluent.kafka.schemaregistry.rest.SchemaRegistryMain.main(SchemaRegistryMain.java:44)
  [2018-01-09 13:09:05,558] ERROR Server died unexpectedly:  (io.confluent.kafka.schemaregistry.rest.SchemaRegistryMain:51)
  java.net.BindException: Address already in use
      at sun.nio.ch.Net.bind0(Native Method)
      at sun.nio.ch.Net.bind(Net.java:433)
      at sun.nio.ch.Net.bind(Net.java:425)
      at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223)
      at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)
      at org.eclipse.jetty.server.ServerConnector.open(ServerConnector.java:321)
      at org.eclipse.jetty.server.AbstractNetworkConnector.doStart(AbstractNetworkConnector.java:80)
      at org.eclipse.jetty.server.ServerConnector.doStart(ServerConnector.java:236)
      at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
      at org.eclipse.jetty.server.Server.doStart(Server.java:366)
      at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
      at io.confluent.kafka.schemaregistry.rest.SchemaRegistryMain.main(SchemaRegistryMain.java:44)
  O2771-C02K648W:confluent-4.0.0 user$ 
  </code></pre>
  
  <p>Please help to solve this error.</p>
  
  <p>Thanks,</p>
  
  <p>When I run command, <code>ps aux | grep schema-registry</code></p>
  
  <pre><code>O2771-C02K648W:~ user$ ps aux | grep schema-registry
  root             20888   0.1  1.5  4584980 255588   ??  S     6:14PM   1:05.15 /usr/bin/java -Xmx512M -server -XX:+UseG1GC -XX:MaxGCPauseMillis=20 -XX:InitiatingHeapOccupancyPercent=35 -XX:+DisableExplicitGC -Djava.awt.headless=true -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false -Dschema-registry.log.dir=/Users/user/Downloads/confluent-4.0.0/bin/../logs -Dlog4j.configuration=file:/Users/user/Downloads/confluent-4.0.0/bin/../etc/schema-registry/log4j.properties -cp :/Users/user/Downloads/confluent-4.0.0/bin/../package-schema-registry/target/kafka-schema-registry-package-*-development/share/java/schema-registry/*:/Users/user/Downloads/confluent-4.0.0/bin/../share/java/confluent-common/*:/Users/user/Downloads/confluent-4.0.0/bin/../share/java/rest-utils/*:/Users/user/Downloads/confluent-4.0.0/bin/../share/java/schema-registry/* io.confluent.kafka.schemaregistry.rest.SchemaRegistryMain ./etc/schema-registry/schema-registry.properties
  root             20887   0.0  0.0  2456112   3452   ??  S     6:14PM   0:00.02 sudo ./bin/schema-registry-start ./etc/schema-registry/schema-registry.properties
  user     25256   0.0  0.0  2432804   1984 s001  S+    1:41PM   0:00.00 grep schema-registry
  O2771-C02K648W:~ user$ 
  </code></pre>