apollo_batcher: remove is_round_mismatch_error

[ArniStarkware]

Note

Medium Risk
Changes pre-confirmed block writing from error-propagating to best-effort by ignoring Cende write failures, which could mask recorder/round issues and affect observability/troubleshooting during proposals.

Overview
Makes the pre-confirmed block writer non-failing: PreconfirmedBlockWriterTrait::run no longer returns a Result, and batcher::spawn_proposal stops discarding an Ok/Err return value.

Removes round-mismatch/error handling in PreconfirmedBlockWriter (including the is_round_mismatch_error path) and instead intentionally ignores errors from in-flight and final write_pre_confirmed_block calls; PreconfirmedCendeClient now logs failures as warn with a TODO to add a failure metric. Test mocks are updated to match the new run() signature.

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[reviewable-StarkWare]

This change is 

[ArniStarkware]

• apollo_batcher: replace preconfirmed block writer pending tasks with singular write task #13233 : 3 dependent PRs (#13278 , #13279 , #13283 )
• apollo_batcher: remove is_round_mismatch_error #13232 👈 (View in Graphite)
• main

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[ArniStarkware]

crates/apollo_batcher/src/pre_confirmed_block_writer.rs line 225 at r1 (raw file):

                    pending_tasks.clear();
                    return Err(error.into());
                }

Note, it is implied here that the other error is not raised.

Suggestion:

                if is_round_mismatch_error(&error, next_write_iteration) {
                    // TODO(noamsp): Remove this since we only have one ongoing write task.
                    pending_tasks.clear();
                    return Err(error.into());
                }
                else {
                    // Intentionally ignore write-task errors (including recorder BAD_REQUEST)
                    // to preserve current best-effort pre-confirmed block writer behavior.
                }

[TzahiTaub]

crates/apollo_batcher/src/pre_confirmed_block_writer.rs line 225 at r1 (raw file):

Previously, ArniStarkware (Arnon Hod) wrote…

Note, it is implied here that the other error is not raised.

Didn't understand your comment. What is the other error? The round mismatch?

[ArniStarkware]

crates/apollo_batcher/src/pre_confirmed_block_writer.rs line 225 at r1 (raw file):

Previously, TzahiTaub (Tzahi) wrote…

Didn't understand your comment. What is the other error? The round mismatch?

The note I wanted to raise was discussed with @ShahakShama.

What I wanted to say is that, before the change, we didn't handle the other variants of PreconfirmedCendeClientError.

[TzahiTaub]

@TzahiTaub reviewed 4 files and all commit messages, and made 1 comment.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on ArniStarkware).

---

crates/apollo_batcher/src/pre_confirmed_block_writer.rs line 124 at r3 (raw file):

            // to preserve current best-effort pre-confirmed block writer behavior.
        }
    }

I see that the write_pre_confirmed_block logs a warning upon failure, and with your todo for the metric there, I don't think there should be anything else here. I think the result can just be ignored in this scope.

Code quote:

    // TODO(Arni): handle this error. Make sure it is logged, and that there is a metric for the
    // failure.
    fn handle_pre_confirmed_cende_client_result(result: PreconfirmedCendeClientResult<()>) {
        if result.is_err() {
            // Intentionally ignore write-task errors (including recorder BAD_REQUEST)
            // to preserve current best-effort pre-confirmed block writer behavior.
        }
    }

[ArniStarkware]

crates/apollo_batcher/src/pre_confirmed_block_writer.rs line 124 at r3 (raw file):

Previously, TzahiTaub (Tzahi) wrote…

I see that the write_pre_confirmed_block logs a warning upon failure, and with your todo for the metric there, I don't think there should be anything else here. I think the result can just be ignored in this scope.

Done.

[ShahakShama]

@ShahakShama reviewed 1 file and all commit messages, and made 1 comment.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on TzahiTaub).

[TzahiTaub]

@TzahiTaub reviewed 1 file and all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on ArniStarkware).