查看日志文件：
2020-01-20 09:31:08,758 ERROR org.apache.flink.runtime.entrypoint.ClusterEntrypoint - Could not start cluster entrypoint StandaloneSessionClusterEntrypoint.
org.apache.flink.runtime.entrypoint.ClusterEntrypointException: Failed to initialize the cluster entrypoint StandaloneSessionClusterEntrypoint.
at org.apache.flink.runtime.entrypoint.ClusterEntrypoint.startCluster(ClusterEntrypoint.java:182)
at org.apache.flink.runtime.entrypoint.ClusterEntrypoint.runClusterEntrypoint(ClusterEntrypoint.java:501)
at org.apache.flink.runtime.entrypoint.StandaloneSessionClusterEntrypoint.main(StandaloneSessionClusterEntrypoint.java:65)
Caused by: org.apache.flink.util.FlinkException: Could not create the DispatcherResourceManagerComponent.
at org.apache.flink.runtime.entrypoint.component.AbstractDispatcherResourceManagerComponentFactory.create(AbstractDispatcherResourceManagerComponentFactory.java:257)
at org.apache.flink.runtime.entrypoint.ClusterEntrypoint.runCluster(ClusterEntrypoint.java:210)
at org.apache.flink.runtime.entrypoint.ClusterEntrypoint.lambda$startCluster$0(ClusterEntrypoint.java:164)
at org.apache.flink.runtime.security.NoOpSecurityContext.runSecured(NoOpSecurityContext.java:30)
at org.apache.flink.runtime.entrypoint.ClusterEntrypoint.startCluster(ClusterEntrypoint.java:163)
... 2 more
Caused by: java.net.BindException: Could not start rest endpoint on any port in port range 8081
at org.apache.flink.runtime.rest.RestServerEndpoint.start(RestServerEndpoint.java:219)
at org.apache.flink.runtime.entrypoint.component.AbstractDispatcherResourceManagerComponentFactory.create(AbstractDispatcherResourceManagerComponentFactory.java:161)
... 6 more
## hecg
看錯誤信息，發現是端口被占用問題，修改配置文件 flink-conf.yaml 中的默認端口：
#==============================================================================
# Rest & web frontend
#==============================================================================
# The port to which the REST client connects to. If rest.bind-port has
# not been specified, then the server will bind to this port as well.
#
#rest.port: 8081
rest.port: 8085
重啟，解決問題!