Provided are techniques for workload balancing. A message is received on a channel. A thread in a thread pool is selected to process the message. In response to determining that the message has been processed and a response has been sent on the channel by the thread, it is determined whether a total number of threads in the thread pool is greater than a low water mark plus one and whether the channel has more than a maximum number of threads blocked on a receive, wherein the low water mark represents a minimum number of threads in the thread pool. In response to determining that a number of threads in the thread pool is greater than the low water mark plus one and that the channel has more than the maximum number of threads blocked on a receive, the thread is terminated. In response to determining at least one of the number of threads in the thread pool is less than or equal to the low water mark plus one and the channel has less than or equal to the maximum number of threads blocked on a receive, the thread is retained.