Welcome to our community! 
That means your node cannot keep up, not the thread pool. Any idea what these errors mean version 2.4.2 - #5 by jasontedor is a really good post on this.
It's a min of 5, but a max of half of the number of processors on the node. So a 32 core CPU will have 16 threads.
And then the node will hold 1000 requests in it's queue before rejecting them.