Hi, I'm having a question regarding Flink. I'm running Flink in stand-alone mode on 1 host (JobManager, TaskManager on the same host). At first, I'm able to submit and cancel jobs normally, the jobs showed up in the web UI and ran. However, after ~1month, when I canceled the old job and submitting a new one, I faced *org.apache.flink.client.program.ProgramInvocationException: Could not retrieve the execution result.* At this moment, I was able to run *flink list* to list current jobs and *flink cancel* to cancel the job, but *flink run* failed. Exception was thrown and the job was now shown in the web UI. When I tried to stop the current stand-alone cluster using *stop-cluster*, it said 'no cluster was found'. Then I had to find the pid of flink processes and stop them manually. Then if I run *start-cluster* to create a new stand-alone cluster, I was able to submit jobs normally. The shortened stack-trace: (full stack-trace at google docs link <https://docs.google.com/document/d/1v07A4Jp45worykjgMyQTVR-BAoPXwL-O9qGxxhNjXyE/edit?usp=sharing> ) org.apache.flink.client.program.ProgramInvocationException: Could not retrieve the execution result. (JobID: 7ef1cbddb744cd5769297f4059f7c531) at org.apache.flink.client.program.rest.RestClusterClient.submitJob (RestClusterClient.java:261) Caused by: org.apache.flink.runtime.client.JobSubmissionException: Failed to submit JobGraph. Caused by: org.apache.flink.runtime.concurrent.FutureUtils$RetryException: Could not complete the operation. Number of retries has been exhausted. Caused by: java.util.concurrent.CompletionException: org.apache.flink.runtime.rest.ConnectionClosedException: Channel became inactive. Caused by: org.apache.flink.runtime.rest.ConnectionClosedException: Channel became inactive. ... 37 more The error is consistent. It always happens after I let Flink run for a while, usually more than 1 month). Why am I not able to submit job to flink after a while? What happened here? Regards,
Son
