Uploaded image for project: 'Hadoop YARN'
  1. Hadoop YARN
  2. YARN-4970

Difficult to trace "Connection Refused" in AM Proxying



    • Improvement
    • Status: Open
    • Minor
    • Resolution: Unresolved
    • 2.6.0
    • None
    • webapp
    • Hadoop-2.6.0-CDH5.5.1, linux


      In generating an HA YARN config (effectively using my own tools for generation), I missed out the multiple specification of yarn.resourcemanager.webapp.address, which produced a "Connection Refused" similar to that in YARN-800 (because of a misunderstanding about what the proxy address was) from the AM webapp.

      It occurs to me, though, in tracing the code, that the behaviour of hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/util/RMHAUtils.java: getRMHAWebappAddresses(YarnConfiguration) should probably mirror the effect of the startup of the resourcemanager itself, such that if the id-suffixed key doesn't exist, you end up using the yarn.resourcemanager.address with the port number replaced by the one taken from yarn.resourcemanager.webapp.address (or its https equivalent). That is, if you had a config like:


      you would end up with ("hosta:8088", "hostb:8088") as the List<String> result of the function above, rather than the current empty list result.

      This would certainly give a better principle of least-surprise for operators of yarn (especially those like myself who ended up configuring it wrongly).

      Thoughts? Reasons why this isn't a good idea? (I'm afraid my Java's a bit read-only which is why I haven't suggested a patch)


        Issue Links



              Unassigned Unassigned
              mbm Matthew Byng-Maddick
              0 Vote for this issue
              4 Start watching this issue