[jira] [Created] (FLINK-5669) flink-streaming-contrib DataStreamUtils.collect in local environment mode fails when offline

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[jira] [Created] (FLINK-5669) flink-streaming-contrib DataStreamUtils.collect in local environment mode fails when offline

Shang Yuanchun (Jira)
Rick Cox created FLINK-5669:
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             Summary: flink-streaming-contrib DataStreamUtils.collect in local environment mode fails when offline
                 Key: FLINK-5669
                 URL: https://issues.apache.org/jira/browse/FLINK-5669
             Project: Flink
          Issue Type: Bug
          Components: flink-contrib
            Reporter: Rick Cox
            Priority: Minor


{{DataStreamUtils.collect()}} needs to obtain the local machine's IP so that the job can send the results back. In the case of local {{StreamEnvironments}}, it uses {{InetAddress.getLocalHost()}}, which attempts to resolve the local hostname using DNS.

If DNS is not available (for example, when offline) or if DNS is available but cannot resolve the hostname (for example, if the hostname is an intranet name but the machine is not currently on that network), an {{UnknownHostException}} will be thrown (and wrapped in an {{IOException}}).
If the resolved IP is not reachable for some reason, streaming results will fail.

Since this case is for local execution only, it seems that using {{InetAddress.getLoopbackAddress()}} would work just as well, and avoid the assumptions made by {{getLocalHost()}}.



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