What causes "Failed to commit verified nonce assignment: {e}" in nautechsystems/nautilus_trader?

Retry the whole nonce-assignment operation; it is transactional, so a failed commit leaves no partial state.

Failed to commit verified nonce assignment: {e}

Error message

Failed to commit verified nonce assignment: {e}

What it means

Thrown when the PostgreSQL transaction that assigns a verified execution nonce fails to commit after all statements succeeded. The database rejects or cannot finalize the transaction (connection loss, serialization failure, constraint violation surfaced at commit), so the entire nonce assignment is rolled back and reported via anyhow.

Source

Thrown at crates/adapters/blockchain/src/cache/database.rs:6039

              AND active
              AND (nonce IS NULL OR nonce = $2)
            ",
        )
        .bind(assignment.intent_id)
        .bind(nonce)
        .execute(&mut *transaction)
        .await
        .map_err(|e| anyhow::anyhow!("Failed to assign verified execution nonce: {e}"))?;
        anyhow::ensure!(
            result.rows_affected() == 1,
            "Execution intent {} is not prepared for canonical nonce {}",
            assignment.intent_id,
            assignment.nonce
        );
        transaction
            .commit()
            .await
            .map_err(|e| anyhow::anyhow!("Failed to commit verified nonce assignment: {e}"))?;
        Ok(())
    }

    /// Appends one verified decision batch before an action on an existing active intent.
    pub(crate) async fn record_execution_verification_batch(
        &self,
        batch: &ExecutionVerificationBatch<'_>,
    ) -> anyhow::Result<()> {
        anyhow::ensure!(
            !batch.decision_class.trim().is_empty() && !batch.decisions.is_empty(),
            "Verified action requires a decision class and evidence"
        );
        anyhow::ensure!(
            batch.provider_ids.len() == 3
                && batch.operator_ids.len() == 3
                && batch.failure_domain_ids.len() >= 3,
            "Verified action requires the configured provider identities"
        );

View on GitHub (pinned to 18893faf8b)

Solutions

Retry the whole nonce-assignment operation; it is transactional, so a failed commit leaves no partial state.
Check database connectivity and logs for connection drops, deadlocks, or serialization failures around the failure time.
Shorten the work done between pool.begin() and commit(), or move non-DB work outside the transaction.
Tune connection pool/statement timeouts (sqlx pool options, statement_timeout) if idle-in-transaction limits are the cause.

Example fix

// before: single attempt
assign_verified_execution_nonce(&pool, &assignment).await?;
// after: retry transient commit failures
for attempt in 0..3 {
    match assign_verified_execution_nonce(&pool, &assignment).await {
        Ok(()) => break,
        Err(e) if attempt < 2 && is_transient_db_error(&e) => tokio::time::sleep(backoff(attempt)).await,
        Err(e) => return Err(e),
    }
}

Defensive patterns

Strategy: retry

Try / catch

// Rust
match assign_nonce().await {
    Err(e) if e.to_string().contains("Failed to commit verified nonce assignment") && is_transient(&e) => retry_with_backoff(),
    Err(e) => return Err(e),
    Ok(v) => Ok(v),
}

Prevention

Keep transactions short; avoid network calls between begin and commit.
Set sane statement_timeout and pool acquire timeouts.
Monitor Postgres for deadlocks and connection drops.

When it happens

Trigger: transaction.commit() returns Err during the verified nonce assignment flow — typically a dropped connection, network partition to Postgres, deadlock, or serialization failure between the UPDATE and commit.

Common situations: Idle-in-transaction timeouts killing the connection; network blips between the app and the database; Postgres failover mid-transaction; long-running verification work holding the transaction open too long.

Related errors

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/04a432702455c803. Report an issue: GitHub.