Reserved Memory and Vcores in negative value in Yarn RM UI

In YARN, resource allocation discrepancies can occur due to the way resource calculation is handled. By default, resource availability is determined based on available memory.

However, when CPU scheduling is enabled, resource calculation considers both available memory and vCores. As a result, in some scenarios, nodes may appear to allocate more vCores than the configured limit while simultaneously displaying lower available resources.

This happens due to the way YARN dynamically assigns vCores based on workload demands rather than strictly adhering to preconfigured limits. Additionally, in cases where CPU scheduling is disabled, YARN relies solely on memory-based resource calculation. This may lead to negative values appearing in the YARN UI, which can be safely ignored, as they do not impact actual resource utilization.