Caught SIGTERM shutting down error in Plesk server causing trouble? We have a solution.

At Bobcares, we offer solutions for every query, big and small, as a part of our Server Management Service.

Let’s take a look at how our Support Team recently helped out a customer with the “caught SIGTERM shutting down“ error.

All about “caught SIGTERM shutting down” error in Plesk server

Have you been noticing any of the following error messages in your Apache log file /(var/log/httpd/error_log for CentOS-based or /var/log/apache2/error.log for Ubuntu-based systems)?

[notice] caught SIGTERM, shutting down

[mpm_prefork:notice] [pid 12450] AH00169: caught SIGTERM, shutting down

[mpm_event:notice] [pid 665:tid 140662910175360] AH00492: caught SIGWINCH, shutting down gracefully

[error] 34053#0: *190501 upstream prematurely closed connection while reading response header from upstream, client: 203.0.113.101, server: example.com, request: "POST /wp-admin/admin-ajax.php HTTP/2.0", upstream: "https://203.0.113.2:7081/wp-admin/admin-ajax.php", host: "example.com", referrer: "https://example.com/"

In some scenarios, the “caught SIGTERM shutting down” error also results in the following multiple messages about Apache restart on the system  journal for Apache service:

Nov 27 08:13:00 servername systemd[1]: Stopping The Apache HTTP Server...
Dec 26 07:13:03 servername systemd[1]: Stopped The Apache HTTP Server.
Dec 26 07:13:03 servername systemd[1]: Starting The Apache HTTP Server...
Dec 26 07:13:05 servername systemd[1]: Started The Apache HTTP Server.
Dec 26 07:13:54 servername systemd[1]: Stopping The Apache HTTP Server...
Dec 26 07:13:57 servername systemd[1]: Stopped The Apache HTTP Server.
Dec 26 07:13:58 servername systemd[1]: Starting The Apache HTTP Server...
Dec 26 07:13:59 servername systemd[1]: Started The Apache HTTP Server.

We may also notice that domains are unavailable. Moreover, we will get the 503 error after deleting a domain/subdomain or issuing an SSL certificate.

How to resolve “caught SIGTERM shutting down error” in Plesk server

Before we head to the solution, let’s take a look at the cause behind this specific error. According to our experienced Support Engineers, Plesk prompts Apache service to restart the new configuration in the following situations:

1. Creating or removing a domain.
2. Issuing, renewing, or assigning an SSL certificate.
3. Changing Hosting Settings or PHP Settings for a domain.

Fortunately, our Support Team has come up with two different solutions to help prevent frequent Apache restarts:

• Option 1: Configuring graceful restart for Apache in Plesk Onyx or Obsidian.
• Option 2: Increasing Apache restart interval in Plesk Onyx. We can do this by navigating to Apache Web Server under Tools & Settings and setting Apache restart interval value to 300 or more as seen below:

  

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Conclusion

In essence, the skilled Support Engineers at Bobcares demonstrated how to resolve the “caught SIGTERM shutting down” error.