@prakharcode 

Thank you for sharing the detailed information about your issue. Before diving into solutions, I want to confirm if this is still an ongoing problem you're facing. Regarding the difference in job performance between "NO_ISOLATION" mode and "USER_ISOLATION" mode, it might be good to dissect the memory space with memory dumps / heap dumps, but generally speaking, I think it makes sense to consider that in "USER_ISOLATION" mode, there are additional isolation layers to ensure that resources are securely allocated to individual users. This isolation can consume extra memory and computational resources, leading to potential OOM errors and performance degradation. For example, "USER_ISOLATION" mode enforces stricter security and isolation policies, which can impact the overall performance of the cluster. This mode is designed to provide better security at the cost of some performance overhead. In your use case, we would have to benchmark and collect more data points to determine more specifically what is the memory utilization and overhead, as well as where is it coming from, what are the biggest contributors/dominators, etc.