@DivyeshS7517 For an external Hazelcast container, the recommended heap size typically starts at 2-4 GB for smaller clusters (less than 10 nodes) and can go up to 8-16 GB for larger clusters or high-load use cases. If you don’t specify a heap size, Java will usually set it based on the available system memory, typically around 1/4 of the total memory. You can explicitly set the heap size using the -Xms (initial heap size) and -Xmx (maximum heap size) flags, such as -Xms2g -Xmx8g. If you're using off-heap memory with Hazelcast, the heap size requirement can be lower. Be mindful of garbage collection tuning for larger heaps to avoid long pauses, and always monitor memory usage for optimal performance.