no problem. Everything works fine - a pleasure to use the framework.
Albeit ... one problem occurs after restarting the master from a checkpoint and reconnecting the slaves. Then each slave evaluates only in single thread mode (despite from evaltreads > 1)
The problem seems to be the "source" of the input of line 473 of "Slave.java"
public static void evaluateSimpleProblemForm( final EvolutionState state, boolean returnIndividuals,
DataInputStream dataIn, DataOutputStream dataOut, String args )
// first load the individuals
473: numInds = dataIn.readInt();
catch (IOException e)
state.output.fatal("Unable to read the number of individuals from the master:\n"+e);
because after checkpointing "numInds" receives always a "1" from the master / in contrast to non-checkpointing.
On May 13, 2013, at 19:26, Sean Luke <[log in to unmask]> wrote:
> Ralf, I'm sorry, I had misinterpreted your earlier posting as saying you had it figured it out.
> You are correct, while Master-Slave allows for dynamic reintroduction of slave units, ECJ's island model does not allow dynamic reintroduction of island units. There's not any real reason for this, except that (1) the island model code was written first [hindsight is 20/20] and (2) dynamic reintroduction is less useful for island models, since islands are supposed to be long-running stateful processes. So we always figured the right strategy in the case of an island failure was to kill everything and restart from checkpoint (which they can do). Perhaps we might add in dynamic reintroduction but it's somewhat complex to do right and a bit low in priority.
> On May 13, 2013, at 6:32 AM, Ralf Buschermöhle wrote:
>> it seems that Master-Slave already does the trick :).
>> I ignored MS because the ReadMe says "Slaves run in single-threaded mode ..." in contrast to the manual and I have a large database for each node/slave (in memory).
>> On May 9, 2013, at 11:32, Ralf Buschermöhle <[log in to unmask]> wrote:
>>> Please ignore async connection ... :)
>>> On May 9, 2013, at 11:28, Ralf Buschermöhle <[log in to unmask]> wrote:
>>>> is it possible to rejoin islands after the connection to the server was lost? (async connection)
>>>> This would allow to introduce computation nodes more flexible (e.g., when not used by other users).