AWS Lightsail - CPU Usage spikes and server crashes

[smnorton]

Platform

AWS

bndiagnostic ID know more about bndiagnostic ID

59eaf570-a346-0e50-dbf3-852f7c505872

bndiagnostic output

===== Begin of bndiagnostic tool output =====

✓ Processes: No issues found
? Mariadb: Found possible issues
? Connectivity: Found possible issues
✓ Php: No issues found
? Apache: Found possible issues
✓ Resources: No issues found
? Wordpress: Found possible issues

[Mariadb]

Found recent error messages in the MariaDB error log:

2025-01-16 22:49:04 88 [Warning] Aborted connection 88 to db:
'bitnami_wordpress' user: 'bn_wordpress' host: '**ip_address**' (Got an error
reading communication packets)

Press [Enter] to continue:
Please check the following guide to troubleshoot MariaDB issues:

https://docs.bitnami.com/general/apps/wordpress/troubleshooting/debug-erro
rs-mariadb/

[Connectivity]

Server ports 22, 80 and/or 443 are not publicly accessible. Please check the
following guide to open server ports for remote access:

https://docs.bitnami.com/general/faq/administration/use-firewall/

[Apache]

Found recent error or warning messages in the Apache error log.

[Thu Jan 16 22:52:47.388605 2025] [proxy_fcgi:error] [pid 53355:tid 53863]
[client **ip_address**:59902] AH01071: Got error 'PHP message: PHP Warning:
Undefined variable $post in
/bitnami/wordpress/wp-content/themes/citygov-child/tribe-events/single-event.php
on line 150; PHP message: PHP Warning: Attempt to read property "ID" on null in
/bitnami/wordpress/wp-content/themes/citygov-child/tribe-events/single-event.php
on line 150'
Press [Enter] to continue:
 [Thu Jan 16 22:53:17.163252 2025] [proxy_fcgi:error] [pid 54017:tid 54222]
[client **ip_address**:50018] AH01071: Got error 'PHP message: PHP Warning:
Undefined variable $post in
/bitnami/wordpress/wp-content/themes/citygov-child/tribe-events/single-event.php
on line 150; PHP message: PHP Warning: Attempt to read property "ID" on null in
/bitnami/wordpress/wp-content/themes/citygov-child/tribe-events/single-event.php
on line 150', referer: [URL REDACTED]/F
[Thu Jan 16 22:55:11.321925 2025] [proxy_fcgi:error] [pid 54017:tid 54252]
[client **ip_address**:58498] AH01071: Got error 'PHP message: PHP Warning:
Undefined variable $post in
/bitnami/wordpress/wp-content/themes/citygov-child/tribe-events/single-event.php
on line 150; PHP message: PHP Warning: Attempt to read property "ID" on null in
/bitnami/wordpress/wp-content/themes/citygov-child/tribe-events/single-event.php
on line 150'

Please check the following guide to troubleshoot server issues:

https://docs.bitnami.com/general/apps/wordpress/troubleshooting/debug-erro
rs-apache/

[Wordpress]

Press [Enter] to continue:
Found recent WordPress plugin related error messages in the Apache error log.

[Thu Jan 16 22:49:04.443335 2025] [proxy_fcgi:error] [pid 52762:tid 52915]
(104)Connection reset by peer: [client **ip_address**:62753] AH01075: Error
dispatching request to : , referer:
[URL REDACTED]/wp-admin/plugins.php

Please check the following guide to deactivate plugins:

https://developer.wordpress.org/cli/commands/plugin/deactivate/

bndiagnostic was not useful. Could you please tell us why?

I'm not sure that the diagnostic tool provided anything meaningful for me to diagnose

Describe your issue as much as you can

I've been facing significant issues with one of my lightsail instances running WordPress over the past few weeks. I had to create a fresh instance and installed a backup of my website over the past weekend because the previous instance mariadb wouldn't start. I see several php-fpm processes running, but do not understand how to find the culprit of my problems.

When I created the fresh instance, everything was working fine for over 24 hours before the server started choking. I managed to grow my burst capacity to about 40% and it has since depleted entirely. I've got w3-total-cache running with a page cache enhanced. The site doesn't receive a ton of traffic, and my instance has 4 GB RAM, 2 vCPUs, and 80 GB SSD.

I'm struggling to resolve this and hope that I can get some help here.