Abstract: Systems and methods are described for providing updating of disk images supporting serverless code execution and controlled deployment of updated disk images. A disk image can be defined as a set of layers that represent a file system include code of a serverless function and other data used by the code. A function owner can designate one layer as containing software or other data subject to update. When a new version of the layer is obtained at a serverless compute system, the system can generate a new disk image containing the updated layer. The system can then gradually transition the function to the new disk image, by dividing calls to the function among two versions of the function—one using the prior disk image, and one using the new disk image. Performance data gained from the new version of the function can be used to control the gradual transition.

Abstract: Systems and methods are described for a multi-tenant mode of a serverless code execution system. For instance, a method may include maintaining a set of execution environments, wherein each execution environment is associated with a serverless function, wherein the serverless function is associated with a software as a service (SaaS) provider that is a tenant of a cloud services provider, wherein the SaaS provider provides services to sub-tenants, wherein the set of execution environments are partitioned based on sub-tenants of the SaaS provider; receiving a call to execute a serverless function, wherein the call includes a serverless function identifier and a sub-tenant identifier; identifying a sub-tenant-specific execution environment of the set of execution environments that is associated with the sub-tenant; and in response to identifying the tenant-specific execution environment, invoking the serverless function on the sub-tenant-specific execution environment.