Apache Flink example job fails to run with "Job not found"

Attempting to run the SocketWindowWordCount example tutorial found on the flink site here.

I started the flink cluster, then ran a local socket server:

nc -l 9000

After compiling the example source taken from github, I run the job

flink run target/SocketWindowWordCount.jar  --port 9000

I then input some words to the terminal running nc. Nothing goes to the expected output file and the log has this error repeating:

2019-07-09 15:54:32,673 ERROR org.apache.flink.runtime.rest.handler.job.JobDetailsHandler   - Exception occurred in REST handler: Job f9b3c58ca3026855fd2612e3c86551fa not found
2019-07-09 15:54:35,673 ERROR org.apache.flink.runtime.rest.handler.job.JobDetailsHandler   - Exception occurred in REST handler: Job f9b3c58ca3026855fd2612e3c86551fa not found
2019-07-09 15:54:38,673 ERROR org.apache.flink.runtime.rest.handler.job.JobDetailsHandler   - Exception occurred in REST handler: Job f9b3c58ca3026855fd2612e3c86551fa not found
2019-07-09 15:54:39,769 ERROR org.apache.flink.runtime.rest.handler.job.JobDetailsHandler   - Exception occurred in REST handler: Job f9b3c58ca3026855fd2612e3c86551fa not found

Solution

This is usually happening when you have a Flink UI tab open in your browser, which is left open from previous job deployments. So the UI is pointing to a URL with http://.../f9b3c58ca3026855fd2612e3c86551fa which is a JobID that doesn't exist. This causes the above log to show up.