{"record":{"id":"9b96c2938e0024bc","repo":"apache/beam","slug":"error-executing-async-task-for-element","errorCode":null,"errorMessage":"Error executing async task for element ","messagePattern":"Error executing async task for element ","errorType":"exception","errorClass":"RuntimeException","httpStatus":null,"severity":"error","filePath":"sdks/java/core/src/main/java/org/apache/beam/sdk/transforms/AsyncWrapper.java","lineNumber":660,"sourceCode":"          continue;\n        }\n\n        if (activeElements.containsKey(elementId)) {\n          InFlightElement<OutputT> inFlight = activeElements.get(elementId);\n          // Future is either completed, cancelled, or throws an exception\n          if (inFlight.future.isDone()) {\n            // Remove from local active map before checking the result\n            activeElements.remove(elementId);\n            try {\n              if (!inFlight.future.isCancelled()) {\n                toReturn.add(inFlight.future.get());\n                // Only mark as finished if future was not cancelled\n                finishedElementIds.add(elementId);\n                itemsFinished++;\n              }\n            } catch (Exception e) {\n              LOG.error(\"Error executing async task for element {}\", element, e);\n              throw new RuntimeException(\"Error executing async task for element \" + element, e);\n            }\n          } else {\n            inFlightElementIds.add(elementId);\n            itemsNotYetFinished++;\n          }\n        } else {\n          logInfo(\n              \"Item \"\n                  + element\n                  + \" found in state but not in local active elements, scheduling now\");\n          toReschedule.add(element);\n          rescheduledElementIds.add(elementId);\n          itemsRescheduled++;\n        }\n      }\n    } finally {\n      lock.unlock();\n    }","sourceCodeStart":642,"sourceCodeEnd":678,"githubUrl":"https://github.com/apache/beam/blob/12126d8942aaf848030c478b4c6a28c6af861c66/sdks/java/core/src/main/java/org/apache/beam/sdk/transforms/AsyncWrapper.java#L642-L678","documentation":"AsyncWrapper polls the Future for each element; if a future completes exceptionally, it logs the failing element and rethrows as RuntimeException('Error executing async task for element ' + element) so the DoFn fails the bundle rather than silently succeeding.","triggerScenarios":"The Callable/fn passed to AsyncJoin (or the awaited future) throws — e.g. an async client call fails, a runtime exception escapes the supplied lambda, or the future is completed exceptionally by user code.","commonSituations":"Network/HTTP errors inside the async call being swallowed into the future; NPEs in the user's fn; using a CompletableFuture that was completedExceptionally; unhandled deserialization errors of the RPC response.","solutions":["Inspect the logged cause ('Error executing async task for element ...' with the full stack) to find the real exception in your fn","Wrap the fn body to catch and translate service exceptions, or configure retries on the async client","Ensure the supplied callable never returns a failed future for expected cases (e.g. convert HTTP errors to retryable results)","Fix the underlying fn bug (NPE, bad response parsing) revealed by the cause"],"exampleFix":"// before\nCompletableFuture.supplyAsync(() -> riskyCall(element))\n// after\nCompletableFuture.supplyAsync(() -> {\n  try { return riskyCall(element); }\n  catch (TransientException e) { return retry(element); }\n});","handlingStrategy":"try-catch","validationCode":"if (fn == null) throw new IllegalArgumentException(\"fn must not be null\");","typeGuard":null,"tryCatchPattern":"try {\n  pipeline.run().waitUntilFinish();\n} catch (RuntimeException e) {\n  if (e.getMessage() != null && e.getMessage().startsWith(\"Error executing async task for element\")) {\n    LOG.error(\"Async fn failed for element; root cause:\", e.getCause());\n  } else { throw e; }\n}","preventionTips":["Wrap fn bodies with explicit exception handling and retries for transient failures","Never let raw RuntimeExceptions escape the async callable","Log/monitor failed futures inside the fn instead of relying on wrapper failure","Test the fn against failure modes (timeouts, malformed responses) before deployment"],"tags":["java","async","future","do-fn"],"backgroundTag":"async-task-execution-failed","analyzedSha":"12126d8942aaf848030c478b4c6a28c6af861c66","analyzedAt":"2026-09-13T01:50:10.254Z","contentChangedAt":"2026-09-13T01:50:10.254Z","schemaVersion":2},"datasetVersion":"2026-09-20T03:17:13.778Z"}