Github user NicoK commented on a diff in the pull request: https://github.com/apache/flink/pull/6294#discussion_r202720265 --- Diff: flink-yarn/src/main/java/org/apache/flink/yarn/configuration/YarnConfigOptions.java --- @@ -65,7 +65,11 @@ key("yarn.containers.vcores") .defaultValue(-1) .withDescription("The number of virtual cores (vcores) per YARN container. By default, the number of vcores" + - " is set to the number of slots per TaskManager, if set, or to 1, otherwise."); + " is set to the number of slots per TaskManager, if set, or to 1, otherwise. In order for this parameter " + + "to be used your cluster must have CPU scheduling enabled. You can do this e.g. by setting the " + + "org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.FairScheduler or enabling " + + "org.apache.hadoop.yarn.util.resource.DominantResourceCalculator for " + + "org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler"); --- End diff -- Also, please put the configuration parameters into some code environment, e.g. `<tt>org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.FairScheduler</tt>`, for the config.html page.
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