| I have pasted a version of your code that uses Template Haskell at | http://hpaste.org/73520. Where did you get stuck? Your version worked like a charm. I'm quite new to Haskell, so I was trying desperately to get TH working: forgot to quote "worker" at mkClosure. | 1. A bug in the SimpleLocalnet backend meant that if you dropped a | worker node findSlaves might not return. I have fixed this and | uploaded it to Hackage as version 0.2.0.5. Updated to version 0.2.0.5 and it's working now. :-) | 2. But even with this fix, you will still need to take into account | that workers may disappear once they have been reported by findSlaves. | spawn will actually throw an exception if the specified node is | unreachable (it is debatable whether this is the right behaviour -- | see below). Added exception catching, thanks. | Note that with these modifications there is still something slightly | unfortunate: if you delete a worker, and then restart it *at the same | port*, the master will not see it. There is a very good reason for | this: Cloud Haskell guarantees reliable ordered message passing, and | we want a clear semantics for this (unlike, say, in Erlang, where you | might send messages M1, M2 and M3 from P to Q, and Q might receive M1, | M3 but not M2, under certain circumstances). We (developers of Cloud | Haskell, Simon Peyton-Jones and some others) are still debating over | what the best approach is here; in the meantime, if you restart a | worker node, just give a different port number. I trust you will make a good decision on this. By the way, my new code with TH and exception catching: http://hpaste.org/73548 Thanks, Thiago.