databendlabs/databend · error

{e}

Error message

{e}

What it means

The jeprof debug dump HTTP handler converts any error returned by dump_profile into an internal-server Error whose message is the underlying error's Display output ("{e}") with a 500 status. It signals that collecting/writing the jemalloc profile (jeprof) failed on the server side.

Solutions

1. Inspect the interpolated message {e} to see the underlying dump_profile failure cause.
2. Verify jeprof and required tooling are installed in the image and jemalloc profiling is enabled.
3. Ensure the temp directory (where the .prof tempfile is created) is writable.
4. Re-run the dump endpoint after fixing the environment; if the cause is code-level, open an issue with the full error string.

match resp.status() {
    StatusCode::OK => parse_profile(resp),
    status => log::error!("jeprof dump failed: {}", resp.text().unwrap_or_default()),
}

When it happens

Trigger: Calling the debug jeprof dump endpoint when dump_profile fails — e.g. the temporary .prof file cannot be used, the jeprof binary is missing, or the profile dump command exits non-zero.

Common situations: Profiling a deployment where jemalloc profiling is disabled at build/runtime, jeprof/perf tooling absent in the container image, or the temp directory is not writable.

Understand the failure class

Background: "API error: {status}" and "HTTP 401/403/404/429/5xx" errors: non-2xx HTTP responses explained — this error's family across 27 libraries.

Related errors

• login_handler expect session id in ctx
• Unsupported format for
• Unsupported source type. Expected path, pandas.DataFrame…
• Access denied: is outside allowed directories
• ContextVar has no value

AI-assisted analysis of databendlabs/databend@288d84d76e (2026-09-11). Data as JSON: /api/errors/73c74088b2450d0b. Report an issue: GitHub.

Appendix: source

Thrown at src/common/http/src/debug/jeprof.rs:36

use poem::Error;
use poem::error::InternalServerError;
use poem::web::IntoResponse;
use poem::web::Query;
use tempfile::Builder;

#[poem::handler]
pub async fn debug_jeprof_dump_handler(
    _req: Option<Query<String>>,
) -> poem::Result<impl IntoResponse> {
    let tmp_file = Builder::new()
        .prefix("heap_dump_")
        .suffix(".prof")
        .tempfile()
        .map_err(InternalServerError)?;

    let path = tmp_file.path();
    let body = dump_profile(&path.to_string_lossy()).map_err(|e| {
        Error::new(
            ErrorCode::from(e.to_string().as_str()),
            StatusCode::INTERNAL_SERVER_ERROR,
        )
    })?;
    let body_len = body.len();

    Ok(body.with_header("content-length", body_len).with_header(
        "Content-Disposition",
        format!("attachment; filename=\"{}\"", &path.to_string_lossy()),
    ))
}

View on GitHub (pinned to 288d84d76e)