How do I write a computer program that spawns many processes but
returns one result?
I suppose the classic example of my query is the federated search. Get
user input. Send it to many remote indexes. Wait. Combine results.
Return. In this scenario when one of the remote indexes is slow things
grind to a halt.
I have a more modern example. Suppose I want to take advantage of many
Web Services. One might be spell checker. Another might be a
thesaurus. Another might be an index. Another might be a user lookup
function. Given this environment, where each Web Service will return
different sets of streams, how do I query each of them simultaneously
and then aggregate the result? I don't want to so this sequentially. I
want to fork them all at once and wait for their return before a
specific time out. In Perl I can use the system command to fork a
process, but I must wait for it to return. There is another Perl
command allowing me to fork a process and keep going but I don't
remember what it is. Neither one of these solutions seem feasible. Is
the idea of threading in Java suppose to be able to address this
Eric Lease Morgan
University Libraries of Notre Dame