Failed to run scheduled task on thread pool – How to solve related issues

Opster Team

Jan-20, Version: 1.7-8.0

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This guide will help you check for common problems that cause the log ” Failed to run scheduled task on thread pool ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: pool, task, thread and threadpool.

Log Context

Log “Failed to run scheduled task [{}] on thread pool [{}]” classname is
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

                     if (logger.isDebugEnabled()) {
                        logger.debug(() -> new ParameterizedMessage("scheduled task [{}] was rejected on thread pool [{}]";
                                command; executor); e);
                (e) -> logger.warn(() -> new ParameterizedMessage("failed to run scheduled task [{}] on thread pool [{}]";
                        command; executor); e));

    public Runnable preserveContext(Runnable command) {
        return getThreadContext().preserveContext(command);


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