pool.on('fail', function() {
// When a remote action fails, any tasks remaining in the pool will be
// cleared. Some actions may be currently executing, so final reporting
// will wait until they have completed and the pool is idle.
pool.clearQueue();
failed = true;
});
var functionpool = require('functionpool');
var pool = new functionpool.Pool(function(delay, done) {
if (delay < 0) {
done(new Error('delay must be greater than zero'));
return;
}
console.log('Working for ' + delay + ' milliseconds...');
setTimeout(function() { done(null, delay) }, delay);
});
function callback(err, result) {
if (err) {
console.log('ERROR: ' + err.name + ' ' + err.message);
return;
}
console.log('Worked for ' + result + ' milliseconds.');
}
pool.add(1000, callback);
pool.add(-1, callback);
// queues work for `host` and collects results.
function work(host) {
results[host] = null;
pool.task(host, function(err) {
results[host] = err || true;
});
}
task(this._name, function() {
var taskArgs = arguments;
var results = {};
var failed = false;
// Allocate a function pool to perform the action on the remote hosts.
// The pool serves as a mechanism to limit the number of simultaneous
// connections that will be established.
var pool = new functionpool.Pool({ size: 5 }, function(host, done) {
function finished(err) {
process.nextTick(function() { done(err); });
};
// Create a new context for this host, within which the action will be
// invoked.
var exec = new Executor(host);
var args = Array.prototype.slice.call(taskArgs);
args.push(finished); // callback is the last argument
self._action.apply(exec, args);
});
pool.on('fail', function() {
// When a remote action fails, any tasks remaining in the pool will be
// cleared. Some actions may be currently executing, so final reporting
// will wait until they have completed and the pool is idle.
pool.clearQueue();
failed = true;
});
pool.on('idle', function() {
report();
if (failed) { return fail(new Error('Remote task failed: ' + self._name)); }
return complete();
});
// queues work for `host` and collects results.
function work(host) {
results[host] = null;
pool.task(host, function(err) {
results[host] = err || true;
});
}
// reports results.
function report() {
var done = self._hosts.filter(function(host) {
var result = results[host];
return (result === true);
});
var failed = self._hosts.filter(function(host) {
var result = results[host];
return (result !== true && result !== null);
});
var incomplete = self._hosts.filter(function(host) {
var result = results[host];
return (result === null);
});
console.info('Task %s: %d/%d complete. (%d done, %d failed)', self._name,
(done.length + failed.length),
self._hosts.length,
done.length,
failed.length);
}
console.info('Invoking %s task on %d hosts.', self._name, self._hosts.length);
for (var i = 0, len = self._hosts.length; i < len; i++) {
work(self._hosts[i]);
}
}, {async: true});
var functionpool = require('functionpool');
var startedAt = Date.now();
var pool = new functionpool.Pool({ size: 3 }, function(delay, done) {
console.log('Working for ' + delay + ' milliseconds...');
setTimeout(done, delay);
});
pool.on('idle', function() {
console.log('Finished (' + (Date.now() - startedAt) + ' ms)');
});
pool.task(1000);
pool.task(2000);
pool.task(3000);
pool.task(1000);