apache/flink · error · RejectedExecutionException

The ExecutorService is shut down already. No Callables can…

Error message

The ExecutorService is shut down already. No Callables can be executed.

What it means

DirectExecutorService can be constructed in a mode (triggerRejectedExecutionException) where any submission after shutdown() throws RejectedExecutionException with this message. This matches the standard ExecutorService contract that a shut-down executor refuses new work, letting callers detect use-after-shutdown deterministically instead of silently running the task.

Solutions

Fix ordering so no submissions happen after shutdown(); cancel the producers first, then shut down.
Guard submission sites with !executor.isShutdown() when late tasks are legal and should be dropped.
Create a fresh DirectExecutorService per lifecycle scope instead of reusing one across shutdown boundaries.

Example fix

// before
executor.shutdown();
executor.execute(task);

// after
executor.shutdown();
if (!executor.isShutdown()) { executor.execute(task); } // or reorder shutdown after all submissions

Defensive patterns

Strategy: validation

Validate before calling

if (!executor.isShutdown()) { executor.execute(task); }

Try / catch

try { executor.execute(task); }
catch (RejectedExecutionException e) { /* executor shut down: drop or re-route the task */ }

Prevention

Cancel/shutdown producers before shutting down the executor.
Guard all submission sites with isShutdown() when late work is droppable.
Scope executor lifetime to the component that owns its tasks.

When it happens

Trigger: Calling execute(), submit(), invokeAll(), or invokeAny() on a DirectExecutorService after shutdown(), when the service was created with rejection-on-shutdown enabled (the default constructor enables it).

Common situations: Components sharing a DirectExecutorService instance that outlives a shutdown in tests or teardown; lifecycle races where a callback submits work during close(); reusing a static executor across test cases that shuts it down per test.

Related errors

AI-assisted analysis of apache/flink@2f3c205e92 (2026-08-14). Data as JSON: /api/errors/b81459f219f95cda. Report an issue: GitHub.

Appendix: source

Thrown at flink-core/src/main/java/org/apache/flink/util/concurrent/DirectExecutorService.java:252

        }

        if (iterator.hasNext()) {
            throw new TimeoutException("Could not finish execution of tasks within time.");
        } else {
            throw new ExecutionException("No tasks finished successfully.", exception);
        }
    }

    @Override
    public void execute(@Nonnull Runnable command) {
        throwRejectedExecutionExceptionIfShutdown();

        command.run();
    }

    private void throwRejectedExecutionExceptionIfShutdown() {
        if (isShutdown() && triggerRejectedExecutionException) {
            throw new RejectedExecutionException(
                    "The ExecutorService is shut down already. No Callables can be executed.");
        }
    }

    static class CompletedFuture<V> implements Future<V> {
        private final V value;
        private final Exception exception;

        CompletedFuture(V value, Exception exception) {
            this.value = value;
            this.exception = exception;
        }

        @Override
        public boolean cancel(boolean mayInterruptIfRunning) {
            return false;
        }

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