Batch Support #142
Batch Support #142
Conversation
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Could that also support adding jobs to already existing batch? Like SleepyJob enqueuing another job that would also be added to the batch. |
@mbajur Definitely. As long as you're in a job that's part of the batch, adding another job to the batch would work fine. It'd be pretty simple to extend the existing code to handle that - something like this would solve your use-case I think? class SleepyJob < ApplicationJob
queue_as :background
def perform(seconds_to_sleep)
Rails.logger.info "Feeling #{seconds_to_sleep} seconds sleepy..."
sleep seconds_to_sleep
batch.enqueue { AnotherJob.perform_later }
end
endI can update the This would only work safely inside of the job - if you were outside of the job, it's possible the batch would finish before the job gets created. |
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Yes that would absolutely do the trick for me :) Thank you! |
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Hi @rosa 👋🏼 Congrats on getting SolidQueue past incubation and under the Rails umbrella officially! I'm sure you've got alot on your plate! Are there any questions I can answer in regards to this PR? I can take the interface/functionality further, but I wanted to discuss it a bit before doing that. If there's anything additional you'd like me to tighten up/try out before discussing it, i'm happy to do so. Also ok to just be on hold and not ready to discuss this further atm. Since it's been a couple months, I figured i'd check in. |
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Hey @jpcamara, so sorry for the delay and the silence here. I just haven't had the proper time to dedicate to this, and I think this requires and deserves more than a quick look. Thank you so much for putting this together! My instinct with this kind of feature is that they require someone to use them before they're ready. From just looking at the code, I'm not quite sure what kind of edge cases and race conditions could arise here. This is how most of Solid Queue has been built: we've used it in HEY before making it "official" for everyone, seeing how it behaves under certain loads and what kind of problems we encounter. We caught and improved quite a few things that way. We don't have a use case for batches right now, so I'm afraid I won't be able to take this feature to this "production-test" point on my side. Do you see yourself using this in a production setting? |
That makes sense! It was a bit of a chicken and an egg issue for me - I wanted to have batches in SolidQueue before starting to transition some things over, because I have code using Sidekiq Pro batches. But I can start experimenting with it now and report back. I'll continue to work on this PR as well in that case, too. |
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Thanks for all the hard work here. I'm a big fan of batch jobs so I've been keeping my eye on this PR for a while. Sidekiq Pro and others support the notion of child batches. Like batch jobs, child batches let you work with a higher level abstraction that conceptually simplifies your background work. While implementing that in this PR would be feature creep, I wanted to raise awareness of it in hopes that we design with its extensibility in mind. Thanks again @jpcamara |
hey @dimroc! I couldn't agree more. I used child batches in Sidekiq recently in a project and it highlighted the need to add them to this PR - it's an important feature. I've been putting alot of work into releasing a blog series on ruby concurrency and it's been eating up my free coding-related time, but i'm prioritizing getting back to this soon. Thanks for the feedback! |
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* Introduces a "batch" concept, similar to batches present in Sidekiq Pro and GoodJob * Batches monitor a set of jobs, and when those jobs are completed can fire off a final job * This introduces a SolidQueue::JobBatch model, as well as the ability to enqueue jobs and associate them with the batch * There are still more ideas to figure out, but this provides a basic batch scaffolding to spark discussion
* This means we can store the arguments and settings by letting the user do `BatchJob.new(arguments).set(options)` * Yield the batch in `enqueue` in case someone needs info from it * When you serialize then deserialize an activejob instance, the arguments are in the serialized_arguments field and can only be transferred over by the private method `deserialize_arguments_if_needed`. This is pretty janky, so there is probably something i'm missing * `perform_all_later` let's us do a perform_later even with instance, which does not seem to be possible on the instances themselves
* Add spec for adding arguments and options to the batch callback
* Spacing, double quotes * Support Ruby < 3.2 by removing the implicit key/variable syntax
* on_failure fires the first time any of the jobs fail, even once * on_success only fires if all jobs work (after retries) * remove unused job_id
* Allows enqueueing a job within a job, as part of the batch
* Parent batches will not complete until all child batches have been completed
* Attach success jobs to the parent batch, not to the current batch (which has already finished at this point)
I've added child batches to this PR @dimroc |
Added support to this PR for enqueueing within a job using the syntax I suggested: |
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@jpcamara just an idea here. Could this functionality become its own gem? Like an add-on for solid_queue? |
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One place I think this could be useful could be rolling back changes. Since the move to SQLite doesn't create jobs to a secondary database until after committing records to the main database, there is no atomic guarantee that both records will commit to both databases, leaving us to need manual rollback logic. Additionally, this reminds me that sidekiq had some atomic writing of batch jobs guarantee, either in pro or enterprise. Same thing might happen if you make a change in your database and call an external API. With SQLite you no longer want to make those changes in your database and make the [long-running] external API call in a transaction. Let's say you have to call stripe twice and want to keep a record of what stage you're at. But something goes wrong with the second stripe call (say the charge is declined) and you need to rollback your database so it's not in an inconsistent state. In this case you can queue the rollback as part of the batch. If memory serves, I think the pattern for this sort of thing is called Sagas, or a DAG such as Elixir has with GenStage. I also found this pattern extremely useful in the past because you can parallelize work more effectively. Say I need to make 1000 remote API calls. Each call should really be in its own job so that it can be retried if it hits the API limits and I need to perform some final job once all 1000 API calls have been made and the batch is complete. |
@mariochavez it's true, it probably could be a gem! Sidekiq has batches as a pro feature, but there is also an open-source gem that mostly supports the same api https://github.com/breamware/sidekiq-batch. There are some gotchas with approaching it that way (one, for instance, around jobs being automatically cleaned up and not being able to do anything but warn users against it). But my main motivation is that I personally want it as a first-class feature of SolidQueue. It's a first-class (albeit paid) feature of Sidekiq, and it's a first-class feature of GoodJob. Being built-in means it's more likely to get use/support and alleviates concerns it may be abandoned at some point. I also think it's a great core feature of a job library. Gush is awesome! It definitely works similarly, though this being backed by a DB in SolidQueue means it has more ACID-type guarantees. Something I would like to see is an even more sophisticated "workflow" type layer that worked with any activejob system, and that's something I've toyed around wtih over the past year. That kind of system I think goes a step beyond, is more complicated, and is better served as a separate gem. I think batch support being included in the job server is a good fit. |
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Thanks for all this work @jpcamara! I'm curious what the expected behavior is with An argument for keeping this in the main gem is to ease integration testing with the other features to increase cohesion and stability. I can see it getting hairy when you stack a few different configurations on top of nested batches, and having to assert proper behavior. https://github.com/rails/solid_queue?tab=readme-ov-file#concurrency-controls |
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I would love to see batches in Solid Queue! My use case is primarily creating workflows. |
Support for batches in SolidQueue!
Batches are a powerful feature in Sidekiq Pro and GoodJob which help with job coordination. A "Batch" is a collection of jobs, and when those jobs meet certain completion criteria it can optionally trigger another job with the batch record as an argument.
The goal of this feature is to:
This PR provides a functional batch implementation. The following scenarios will work:
You should see the following in your logs:
Here is the full interface, demonstrating a few different options:
Here are the things that are open questions and missing implementation details:
JobBatchthe right name? General feedback on naming in the featureon_success,on_finish,on_failurediscard_onby marking the job as finished. That means the batch cannot identify that the job actually failed.