title: PHP_FPM error - "oops, unknown child (538) exited with code 0"
body: <p>I am trying to start up my <strong>PHP YII1</strong> framework based application in docker containers. However, PHP_FPM is not properly getting started.</p>
  <p>After running: <code>exec /usr/sbin/php-fpm -F -c /etc/php.ini --fpm-config /etc/php-fpm.conf</code>     within a shell script, the application is supposed to start up. However, I m getting an internal error.</p>
  <p>When checking the docker logs, below is the result:</p>
  <blockquote>
  <p>[18-Aug-2021 18:44:46] NOTICE: Terminating ...<br />
  [18-Aug-2021 18:44:46] NOTICE: exiting, bye-bye!<br />
  [18-Aug-2021 18:44:47] NOTICE: fpm is running, pid 1<br />
  [18-Aug-2021 18:44:48] NOTICE: ready to handle connections<br />
  [18-Aug-2021 18:44:48] NOTICE: systemd monitor disabled<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (538) exited with code 0. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (539) exited with code 1. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (540) exited with code 0. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (544) exited with code 0. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (545) exited with code 1. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (546) exited with code 0. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (541) exited with code 0. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (542) exited with code 1. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (543) exited with code 0. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (556) exited with code 0. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (557) exited with code 1. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (558) exited with code 0. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (559) exited with code 0. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (560) exited with code 1. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (561) exited with code 0. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (562) exited with code 0. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (563) exited with code 1. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (564) exited with code 0. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (565) exited with code 0. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (566) exited with code 1. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (567) exited with code 0. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (547) exited with code 0. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (548) exited with code 1. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (549) exited with code 0. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (550) exited with code 0. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (551) exited with code 1. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (552) exited with code 0. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (553) exited with code 0. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (554) exited with code 1. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (555) exited with code 0. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (568) exited with code 0. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (569) exited with code 1. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (570) exited with code 0. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (571) exited with code 0. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (572) exited with code 1. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:01:44] ALERT: oops, unknown child (573) exited with code 0. Please open a bug report (<a href="https://bugs.php.net" rel="nofollow noreferrer">https://bugs.php.net</a>).<br />
  [18-Aug-2021 19:04:05] NOTICE: Terminating ...<br />
  [18-Aug-2021 19:04:05] NOTICE: exiting, bye-bye!<br />
  [18-Aug-2021 19:04:06] NOTICE: fpm is running, pid 1<br />
  [18-Aug-2021 19:04:06] NOTICE: ready to handle connections<br />
  [18-Aug-2021 19:04:06] NOTICE: systemd monitor disabled</p>
  </blockquote>
  <p>Does anyone know what this error is and how to fix it?</p>