What causes "Failed to load account ids: {e}" in nautechsystems/nautilus_trader?

Confirm DB connectivity and correct DSN in the pool configuration

Failed to load account ids: {e}

Error message

Failed to load account ids: {e}

What it means

This error wraps sqlx failures while querying the list of distinct account ids in `load_accounts`. The SELECT that returns account ids failed, so no accounts can be loaded. The underlying sqlx error is embedded in the message.

Source

Thrown at crates/infrastructure/src/sql/queries.rs:1224

    ///
    /// # Errors
    ///
    /// Returns an error if loading events or SQL operations fail.
    pub async fn load_accounts(pool: &PgPool) -> anyhow::Result<Vec<AccountAny>> {
        let mut accounts: Vec<AccountAny> = Vec::new();
        let account_ids: Vec<AccountId> = sqlx::query(
            r#"
            SELECT DISTINCT account_id FROM "account_event"
        "#,
        )
        .fetch_all(pool)
        .await
        .map(|rows| {
            rows.into_iter()
                .map(|row| AccountId::from(row.get::<&str, _>(0)))
                .collect()
        })
        .map_err(|e| anyhow::anyhow!("Failed to load account ids: {e}"))?;
        for id in account_ids {
            let account = Self::load_account(pool, &id).await?;
            if let Some(account) = account {
                accounts.push(account);
            }
        }
        Ok(accounts)
    }

    /// Inserts a `TradeTick` entry via the provided `pool`.
    ///
    /// # Errors
    ///
    /// Returns an error if the SQL INSERT operation fails.
    pub async fn add_trade(pool: &PgPool, trade: &TradeTick) -> anyhow::Result<()> {
        sqlx::query(r#"
            INSERT INTO "trade" (
                instrument_id, price, quantity, aggressor_side, venue_trade_id,

View on GitHub (pinned to 18893faf8b)

Solutions

Confirm DB connectivity and correct DSN in the pool configuration
Run schema migrations so the account-event table exists
Inspect the wrapped sqlx error in `{e}` (undefined table, connection refused, timeout) and address it
Add retry with backoff for transient connection errors

Defensive patterns

Strategy: retry

Validate before calling

sqlx::query("SELECT 1 FROM account_event LIMIT 1").fetch_optional(pool).await.map_err(|e| anyhow::anyhow!("schema check: {e}"))?;

Try / catch

let ids = load_account_ids(pool).await?; // add backoff retry around this for transient errors
for attempt in 0..3 {
    match load_accounts(pool).await { Ok(a) => break a, Err(e) if attempt == 2 => return Err(e), Err(_) => tokio::time::sleep(backoff).await }
}

Prevention

Run migrations before first use
Configure sensible pool size and connect timeouts
Add retry/backoff for transient connection errors

When it happens

Trigger: Calling `load_accounts(pool)` when the database is unreachable, the backing table is missing (migrations not applied), the query times out, or the pool has no usable connections.

Common situations: Fresh environment where migrations were never run; wrong DSN/env config; Postgres restart mid-request; timeouts with many accounts.

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

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/6f889a060f27f727. Report an issue: GitHub.