nautechsystems/nautilus_trader · error · anyhow::Error

Failed to get pool snapshot validation state: {e}

Error message

Failed to get pool snapshot validation state: {e}

What it means

This wraps a SQLx failure from the SELECT that reads the persisted `validation_state` for a snapshot at a specific watermark. A missing row is a normal `None` result; this error only fires when the query itself fails (connection, schema, driver issue).

Source

Thrown at crates/adapters/blockchain/src/cache/database.rs:2638

        let row = sqlx::query(
            "
            SELECT validation_state
            FROM pool_snapshot
            WHERE chain_id = $1
            AND pool_identifier = $2
            AND block = $3
            AND transaction_index = $4
            AND log_index = $5
            ",
        )
        .bind(chain_id as i32)
        .bind(pool_identifier.as_ref())
        .bind(block as i64)
        .bind(transaction_index as i32)
        .bind(log_index as i32)
        .fetch_optional(&self.pool)
        .await
        .map_err(|e| anyhow::anyhow!("Failed to get pool snapshot validation state: {e}"))?;

        Ok(row.map(|row| row.get::<String, _>("validation_state")))
    }

    /// Loads all positions for a specific snapshot.
    ///
    /// # Errors
    ///
    /// Returns an error if the database query fails.
    pub async fn load_pool_positions_for_snapshot(
        &self,
        chain_id: u32,
        pool_identifier: &PoolIdentifier,
        snapshot_block: u64,
        snapshot_transaction_index: u32,
        snapshot_log_index: u32,
    ) -> anyhow::Result<Vec<PoolPosition>> {
        let rows = sqlx::query(

View on GitHub (pinned to 18893faf8b)

Solutions

1. Verify database connectivity and that migrations created the `validation_state` column.
2. Check Postgres role grants — SELECT must be allowed on the snapshot table.
3. Recycle the sqlx connection pool if the DB was recently restarted.
4. Read the chained `{e}` message for the underlying driver error details.

Example fix

// before: propagate bare error
let state = store.get_validation_state(...).await?;
// after: distinguish empty vs failure and log cause
let state = store.get_validation_state(...).await
    .map_err(|e| { tracing::warn!(cause = ?e.source(), "validation state read failed"); e })?;

sqlx::query("SELECT 1").execute(&db).await?; // cheap liveness probe before state reads

let state = match store.get_validation_state(...).await {
    Ok(s) => s, // None simply means no row
    Err(e) if is_transient(&e) => { backoff_and_retry().await }
    Err(e) => return Err(e),
};

When it happens

Trigger: Calling the validation-state getter when Postgres is unreachable, the snapshot table or `validation_state` column doesn't exist (migrations not applied), or the connection pool is exhausted/timed out.

Common situations: Adapter running against an unmigrated database after an upgrade; DB restart leaving stale pooled connections; permission changes revoking SELECT on the snapshot table.

Understand the failure class

Background: Database query failed: Internal Server Error 500s wrapping SQL, Prisma, and connection failures — what to check first — this error's family across 16 libraries.

Related errors

• Failed to seed chain table: {e}
• Failed to call create_block_partition for chain {}: {e}
• Failed to call create_token_partition for chain {}: {e}
• Failed to get block info for chain {}: {}
• Failed to insert into block table: {e}

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/8c786f0b137c421d. Report an issue: GitHub.