{"record":{"id":"920948dea660b4de","repo":"FuelLabs/fuel-core","slug":"timeout-while-waiting-for-the-required-fuel-block","errorCode":null,"errorMessage":"Timeout while waiting for the required fuel block height: {}","messagePattern":"Timeout while waiting for the required fuel block height: (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"warning","filePath":"crates/fuel-core/src/graphql_api/extensions/required_fuel_block_height.rs","lineNumber":250,"sourceCode":"    error\n}\n\nasync fn await_block_height(\n    block_height_subscriber: &block_height_subscription::Subscriber,\n    block_height: &BlockHeight,\n    timeout: &Duration,\n) -> anyhow::Result<()> {\n    tokio::select! {\n        biased;\n        block_height_res = block_height_subscriber.wait_for_block_height(*block_height) => {\n            block_height_res.map_err(|e| {\n                anyhow::anyhow!(\n                    \"Failed to wait for the required fuel block height: {}\",\n                    e\n                )})\n        },\n        _ = tokio::time::sleep(*timeout) => {\n            Err(anyhow::anyhow!(\n                \"Timeout while waiting for the required fuel block height: {}\",\n                block_height\n            ))\n        }\n    }\n}\n\n#[cfg(test)]\nmod tests {\n    use super::*;\n    use crate::graphql_api::extensions::unify_response;\n    use async_graphql::Response;\n    use std::collections::BTreeMap;\n\n    #[test]\n    fn unify_response_method_is_updated() {\n        // Given\n        let original_error =","sourceCodeStart":232,"sourceCodeEnd":268,"githubUrl":"https://github.com/FuelLabs/fuel-core/blob/b9d4d170da3a31c9ace5f963d633b326348e0d42/crates/fuel-core/src/graphql_api/extensions/required_fuel_block_height.rs#L232-L268","documentation":"The other branch of await_block_height in the @requiredFuelBlockHeight extension: a tokio::time::sleep(timeout) races the block-height wait, and if the timeout elapses first the request fails with this message. It exists so queries requiring a specific block height do not hang forever when block production/import stalls.","triggerScenarios":"A GraphQL request requiring block N does not observe height N within the configured timeout — blocks not being produced (test/pimestamp environments), node lagging behind the network, or an unreachable/unrealistic required height.","commonSituations":"Timeout configured too low for the block production interval; node out of sync or stalled import pipeline; clients requiring a height far in the future; slow disk starving block import.","solutions":["Increase the extension's timeout so it comfortably exceeds expected block time plus import latency.","Check that the node is synced and importing blocks (watch block height metrics) before issuing height-pinned queries.","Only require heights that are recent and realistic; derive them from the node's current height, not client-side guesses."],"exampleFix":"// before\nlet timeout = Duration::from_secs(5);\n\n// after\n// block time ~1s plus import/commit headroom\nlet timeout = Duration::from_secs(30);","handlingStrategy":"retry","validationCode":"// Client side: only pin a height the node can plausibly reach within the timeout.\nlet current = fetch_latest_height().await?;\nif required_height.saturating_sub(current) as u64 * expected_block_time_secs > timeout_secs {\n    return Err(anyhow::anyhow!(\"required height unreachable within timeout\"));\n}","typeGuard":null,"tryCatchPattern":"// Server config or client: retry with backoff while the node catches up.\nlet mut backoff = Duration::from_millis(500);\nfor _ in 0..3 {\n    match query_with_required_height(h).await {\n        Ok(r) => return Ok(r),\n        Err(e) if e.contains(\"Timeout while waiting for the required fuel block height\") => {\n            tokio::time::sleep(backoff).await;\n            backoff *= 2;\n            continue;\n        }\n        Err(e) => return Err(e),\n    }\n}","preventionTips":["Set the extension timeout to several block intervals plus import headroom.","Confirm the node is synced before issuing height-pinned queries.","Derive required heights from recent observed heights instead of client-side extrapolation."],"tags":["graphql","extension","timeout","block-height","rust"],"backgroundTag":null,"analyzedSha":"b9d4d170da3a31c9ace5f963d633b326348e0d42","analyzedAt":"2026-08-16T08:56:42.692Z","schemaVersion":2},"datasetVersion":"2026-08-16T13:17:31.715Z"}