Systems and methods for distributed storage and processing systems using storage controllers for load sharing are described. A host processor may receive a function request that corresponds to a plurality of compute tasks, such as map compute tasks targeting data in local storage. The host processor may fetch the data from local storage devices through storage controllers. At least one storage controller, such as a non-volatile memory express (NVMe) interface controller, may be configured to execute overflow tasks for the function request. Another storage controller may be configured for executing other processing and management activities, such as reduce compute tasks.