alibaba/arthas · error · IllegalStateException

Cannot run proces in {} state

Error message

Cannot run proces in {} state

What it means

Thrown by Process.run() when processStatus is not READY. A process can only transition from READY to RUNNING once; calling run() on an already-running, stopped, or terminated process is illegal. (Note: the message contains a typo 'proces'.) This guards against double-execution of a command process.

Source

Thrown at core/src/main/java/com/taobao/arthas/core/shell/system/impl/ProcessImpl.java:322

        } finally {
            if (completionHandler != null) {
                completionHandler.handle(null);
            }
            if (terminatedHandler != null && statusUpdate == ExecStatus.TERMINATED) {
                terminatedHandler.handle(exitCodeUpdate);
            }
        }
    }

    @Override
    public void run() {
        run(true);
    }

    @Override
    public synchronized void run(boolean fg) {
        if (processStatus != ExecStatus.READY) {
            throw new IllegalStateException("Cannot run proces in " + processStatus + " state");
        }

        processStatus = ExecStatus.RUNNING;
        processForeground = fg;
        foreground = fg;
        startTime = new Date();

        // Make a local copy
        final Tty tty = this.tty;
        if (tty == null) {
            throw new IllegalStateException("Cannot execute process without a TTY set");
        }

        process = new CommandProcessImpl(this, tty);
        if (resultDistributor == null) {
            resultDistributor = new TermResultDistributorImpl(process, ArthasBootstrap.getInstance().getResultViewResolver());
        }

View on GitHub (pinned to 21cf2e9ba5)

Solutions

1. Create a new Process/Job instance for each execution rather than re-running the same one.
2. Guard run() with a status check to ensure the process is still READY.

Example fix

// before
process.run();  // may throw if already run
process.run();

// after: create a fresh process for re-execution
if (process.status() == ExecStatus.READY) {
    process.run();
} else {
    process = jobController.createJob(/* ... */);
    process.run();
}

if (process.status() == ExecStatus.READY) {
    process.run();
} else {
    // create a new process for re-execution
}

boolean canRun(Process p) {
    return p.status() == ExecStatus.READY;
}

try {
    process.run(fg);
} catch (IllegalStateException e) {
    if (e.getMessage().contains("Cannot run proces")) {
        // already started; create a new process if re-execution is needed
    }
}

When it happens

Trigger: run() is invoked twice on the same Process instance, or a process that was previously run and terminated is submitted for execution again.

Common situations: A job scheduler or custom integration that retries run() after a failure without creating a fresh process. Concurrency bugs where two threads start the same process.

Related errors

• Cannot interrupt process in {} state
• Cannot resume process in {} state
• Cannot suspend process in {} state
• Cannot set to background a process in {} state
• Cannot set to foreground a process in {} state

AI-assisted analysis of alibaba/arthas@21cf2e9ba5 (2026-08-14). Data as JSON: /api/errors/63c6644e727c7464. Report an issue: GitHub.