After upgrading to Magento 2.4, I've been unable to run a stable production environment. HTTPD spawns the maximum number of processes and uses all of my systems memory and swap (it takes 5-20 minutes to reach this point).
I'm constantly seeing the following errors in httpd error_log:
[Mon Aug 17 19:40:48.077047 2020] [php7:error] [pid 16939:tid 140670127806208] [client 127.0.0.1:40644] PHP Fatal error: Allowed memory size of 792723456 bytes exhausted (tried to allocate 20480 bytes) in /var/www/html/vendor/magento/module-csp/Model/BlockCache.php on line 108
[Mon Aug 17 19:40:48.125051 2020] [php7:error] [pid 16939:tid 140670127806208] [client 127.0.0.1:40644] PHP Fatal error: Allowed memory size of 792723456 bytes exhausted (tried to allocate 40960 bytes) in Unknown on line 0
[Mon Aug 17 19:40:50.052935 2020] [php7:error] [pid 16932:tid 140669993522944] [client 127.0.0.1:40654] PHP Fatal error: Allowed memory size of 792723456 bytes exhausted (tried to allocate 48238592 bytes) in /var/www/html/vendor/magento/framework/Serialize/Serializer/Json.php on line 24
[Mon Aug 17 19:40:51.592030 2020] [php7:error] [pid 16933:tid 140670169769728] [client 127.0.0.1:40666] PHP Fatal error: Allowed memory size of 792723456 bytes exhausted (tried to allocate 20480 bytes) in /var/www/html/vendor/magento/module-csp/Model/BlockCache.php on line 108
[Mon Aug 17 19:41:12.706529 2020] [php7:error] [pid 17146:tid 140670127806208] [client 127.0.0.1:40702] PHP Fatal error: Allowed memory size of 792723456 bytes exhausted (tried to allocate 20480 bytes) in /var/www/html/vendor/magento/module-csp/Model/BlockCache.php on line 108
[Mon Aug 17 19:41:12.740424 2020] [php7:error] [pid 17146:tid 140670127806208] [client 127.0.0.1:40702] PHP Fatal error: Allowed memory size of 792723456 bytes exhausted (tried to allocate 122880 bytes) in Unknown on line 0
[Mon Aug 17 19:41:24.887257 2020] [php7:error] [pid 16939:tid 140670111020800] [client 127.0.0.1:40798] PHP Fatal error: Allowed memory size of 792723456 bytes exhausted (tried to allocate 4096 bytes) in /var/www/html/vendor/magento/module-csp/Model/BlockCache.php on line 78
[Mon Aug 17 19:41:24.913106 2020] [php7:error] [pid 16939:tid 140670111020800] [client 127.0.0.1:40798] PHP Fatal error: Allowed memory size of 792723456 bytes exhausted (tried to allocate 65536 bytes) in Unknown on line 0
[Mon Aug 17 19:41:39.997127 2020] [php7:error] [pid 16933:tid 140670152984320] [client 127.0.0.1:40904] PHP Fatal error: Allowed memory size of 792723456 bytes exhausted (tried to allocate 20480 bytes) in /var/www/html/vendor/magento/module-csp/Model/BlockCache.php on line 108, referer: http://ip-of-my-ec2-instance:80/
[Mon Aug 17 19:41:40.030659 2020] [php7:error] [pid 16933:tid 140670152984320] [client 127.0.0.1:40904] PHP Fatal error: Allowed memory size of 792723456 bytes exhausted (tried to allocate 40960 bytes) in Unknown on line 0, referer: http://ip-of-my-ec2-instance:80/
[Mon Aug 17 19:42:08.849538 2020] [php7:error] [pid 17146:tid 140670111020800] [client 127.0.0.1:41016] PHP Fatal error: Allowed memory size of 792723456 bytes exhausted (tried to allocate 20480 bytes) in /var/www/html/vendor/magento/framework/Serialize/Serializer/Json.php on line 42
[Mon Aug 17 19:42:08.865389 2020] [php7:error] [pid 17146:tid 140670111020800] [client 127.0.0.1:41016] PHP Fatal error: Allowed memory size of 792723456 bytes exhausted (tried to allocate 32768 bytes) in Unknown on line 0
[Mon Aug 17 19:44:23.245570 2020] [php7:error] [pid 17146:tid 140670027093760] [client 127.0.0.1:41798] PHP Fatal error: Allowed memory size of 792723456 bytes exhausted (tried to allocate 20480 bytes) in /var/www/html/vendor/magento/framework/Serialize/Serializer/Json.php on line 42, referer: https://www.google.com/
[Mon Aug 17 19:44:23.312177 2020] [php7:error] [pid 17146:tid 140670027093760] [client 127.0.0.1:41798] PHP Fatal error: Allowed memory size of 792723456 bytes exhausted (tried to allocate 45056 bytes) in Unknown on line 0, referer: https://www.google.com/
[Mon Aug 17 19:44:29.224653 2020] [php7:error] [pid 16939:tid 140670052271872] [client 127.0.0.1:41742] PHP Fatal error: Allowed memory size of 792723456 bytes exhausted (tried to allocate 20480 bytes) in /var/www/html/vendor/magento/module-csp/Model/BlockCache.php on line 108
[Mon Aug 17 19:44:29.264725 2020] [php7:error] [pid 16939:tid 140670052271872] [client 127.0.0.1:41742] PHP Fatal error: Allowed memory size of 792723456 bytes exhausted (tried to allocate 90112 bytes) in Unknown on line 0
[Mon Aug 17 19:44:34.254009 2020] [php7:error] [pid 17146:tid 140670043879168] [client 127.0.0.1:41688] PHP Fatal error: Allowed memory size of 792723456 bytes exhausted (tried to allocate 20480 bytes) in /var/www/html/vendor/magento/module-csp/Model/BlockCache.php on line 108
[Mon Aug 17 19:44:34.294439 2020] [php7:error] [pid 17146:tid 140670043879168] [client 127.0.0.1:41688] PHP Fatal error: Allowed memory size of 792723456 bytes exhausted (tried to allocate 36864 bytes) in Unknown on line 0
[Mon Aug 17 19:44:40.650547 2020] [php7:error] [pid 17146:tid 140670010308352] [client 127.0.0.1:41882] PHP Fatal error: Allowed memory size of 792723456 bytes exhausted (tried to allocate 20480 bytes) in /var/www/html/vendor/magento/framework/Serialize/Serializer/Json.php on line 42
[Mon Aug 17 19:44:40.690603 2020] [php7:error] [pid 17146:tid 140670010308352] [client 127.0.0.1:41882] PHP Fatal error: Allowed memory size of 792723456 bytes exhausted (tried to allocate 49152 bytes) in Unknown on line 0
[Mon Aug 17 19:44:49.990225 2020] [php7:error] [pid 16939:tid 140670144591616] [client 127.0.0.1:42006] PHP Fatal error: Allowed memory size of 792723456 bytes exhausted (tried to allocate 33554440 bytes) in /var/www/html/vendor/magento/module-csp/Model/Collector/DynamicCollector.php on line 31
Before upgrading to 2.4, I switched to Elasticsearch 6.7 and upgraded to php7.3 (7.4 isn't available on Amazon Linux AMI as far as I can tell). My system.log and exception.log don't show any relevant errors. What can I do to debug this?