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This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/13381/
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Review request for mesos, Benjamin Hindman and Vinod Kone.
Repository: mesos-git
Description
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Throwing this up as a bit of a straw man proposal.
I have code upstream in a branch where I'd like to collect a set of futures,
but I'd like to process a partial result. That is, it is not a failure if any
of the Futures fail or become discarded. When this occurs, I would still like
to process all of the Futures that were successful.
Simplified code below for using collect2:
{
list<Future<ResourceStatistics> > futures;
foreachkey (const FrameworkID& frameworkId, executors) {
foreachkey (const ExecutorID& executorId, executors[frameworkId]) {
futures.push_back(
dispatch(isolator, &Isolator::usage, frameworkId, executorId));
}
}
return process::collect2(futures)
.then(lambda::bind(
__statisticsJSON,
lambda::_1));
}
Future<http::Response> __statisticsJSON(
const list<Future<ResourceStatistics> >& statistics)
{
foreach (const Future<ResourceStatistics>& stats, statistics) {
// Ignore failed / discarded results, possibly log warnings.
if (stats.isFailed() || stats.isDiscarded()) {
continue;
}
CHECK(stats.isReady());
// Process the statistics.
}
return http::OK(result, jsonp);
}
One approach is to create a collect2 as above, which returns once all the
Futures have transitioned states. If we go with this approach, what are
appropriates names instead of collect2?
Alternatively, I could have my code iteratively retry until it gets a
successful collect() result. However, it requires a guard against infinite
retries.
Thoughts?
Diffs
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3rdparty/libprocess/include/process/collect.hpp
3c620aa7ab2af1a8348c1fb190cbf490a7cf1a60
Diff: https://reviews.apache.org/r/13381/diff/
Testing
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make check (I will add a test if we like this approach).
Thanks,
Ben Mahler
