import fastq from 'fastq';
const worker = async ({ index, retries }) => {
console.log({ index, retries });
throw new Error('Oops');
};
const queue = fastq.promise(worker, 1);
queue.error((err, { index, retries }) => {
if (err) {
if (retries) {
queue.unshift({ index, retries: retries - 1 });
// queue.push({ index, retries: retries - 1 });
} else {
console.log({ err }, 'all retries failed');
}
}
});
queue.push({ index: 0, retries: 3 });
await queue.drain();I would like to implement a simple retry mechanism with fastq(1.15.0)'s error handler, like every task got 3 more chances. So for the following tries, I would prefer them to be unshifted into the queue. But the log looks like:
{ index: 0, retries: 3 }
{ index: 0, retries: 2 }
What I expected is the log like this which is replacing unshift() with push() :
{ index: 0, retries: 3 }
{ index: 0, retries: 2 }
{ index: 0, retries: 1 }
{ index: 0, retries: 0 }
{
err: Error: Oops
at worker (file:///home/agu/workspace/TimeFabric/livefeed/api/src/queDemo.js:5:9)
at asyncWrapper (/home/agu/workspace/TimeFabric/livefeed/api/node_modules/fastq/queue.js:213:12)
at Task.release (/home/agu/workspace/TimeFabric/livefeed/api/node_modules/fastq/queue.js:149:16)
at worked (/home/agu/workspace/TimeFabric/livefeed/api/node_modules/fastq/queue.js:201:10)
} all retries failed
so the worker got executed 4 times before giving up.
I do not know why unshift only got the work executed once. But unshift is what I want in this queue, because an immediate retry may just get it done. It does not have to retry it later or wait all over again.
I would like to implement a simple retry mechanism with fastq(1.15.0)'s error handler, like every task got 3 more chances. So for the following tries, I would prefer them to be
unshifted into the queue. But the log looks like:What I expected is the log like this which is replacing
unshift()withpush():so the worker got executed 4 times before giving up.
I do not know why
unshiftonly got the work executed once. Butunshiftis what I want in this queue, because an immediate retry may just get it done. It does not have toretry it laterorwait all over again.