1. A method for dispatching a first message for processing comprising: receiving the first message, wherein the first message is associated with a first actor of a plurality of actors associated with a computing system; determining whether the first actor is assigned to one of a plurality of processing threads within the computing system; selecting a first processing thread for processing the first message based, at least in part, on whether the first actor is assigned to one of the plurality of processing threads; queueing the first message for processing by the first processing thread; and performing a migration on the first processing thread, wherein the migration is performed based at least in part on a message wait time exceeding a threshold, wherein the migration comprises: de-queueing second messages from a queue of the first processing thread; re-queueing the second messages into another message queue; and re-dispatching each of the second messages, wherein the re-dispatching of each of the second messages comprises selecting a processing thread to which an associated actor is assigned or, when the associated actor is not assigned to any of the plurality of processing threads, selecting, based at least in part on a set of priorities associated with the plurality of processing threads, a processing thread for processing of the second message and assigning the associated actor to the processing thread that is selected for processing of the second message.