Limit network actions per batch #3415
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Allow it to be read from other crates.
Prepare to limit the number of network actions created in a single batch.
Add a builder method to set the configuration option.
Ensure that the server has a network actions batch limit set.
Truncate the number of network actions added to a batch.
Avoid retrying to send network actions to the same recipients endlessly.
ma2bd
reviewed
Feb 26, 2025
| targets.truncate(limit); | ||
| } | ||
| } | ||
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| if let Some(tracked_chains) = self.tracked_chains.as_ref() { | ||
| let publishers = self | ||
| .chain |
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Personally, I was only worried about returning too many NetworkActions, so I'm a little bit on fence regarding the randomization idea. Let's see what others think...
afck
reviewed
Feb 26, 2025
| if let Some(limit) = self.config.network_actions_batch_limit { | ||
| if limit > targets.len() / 2 { | ||
| let elements_to_discard = targets.len().saturating_sub(limit); | ||
| targets.partial_shuffle(&mut thread_rng(), elements_to_discard); |
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Why not just use choose_multiple? That should be faster, not require the case distinction, and the order of the selected elements doesn't really matter that much. I guess the downside is that it clones the entries, but they are small, I think?
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Motivation
There's a risk of
O(n^2)behavior in the chain worker, because when network actions are created (for cross-chain messages) all outboxes are inspected in order to figure out which actions should be created. However, the outboxes are only emptied after a confirmation of the receipt from the receiver. This means that until that confirmation is received, the same network actions might be created again and again, stressing the cross-chain channels.Proposal
Limit the number of outboxes inspected to create the network actions. The limit is configured on server shards to be equal to the cross-shard communication channel queue size. If the limit is reached, random outboxes are skipped when creating a new batch of network actions.
Test Plan
CI should catch any regressions.
TODO: should we add a stress test for this scenario?
Release Plan
devnetbranch, thentestnetbranch, thenBecause this could be related to a performance issue the testnet is running into.
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