On a dedicated server with 16 GB RAM running a single Magento site, we have been constantly facing high cpu loads. Running top, we find several php and defunct php processes generating as high as 98% cpu loads.
But, here's the strange thing - when we identify the parent pid of the defunct process and then strace the parent pid, we get the message that there is no such process. Sometimes, we get the same results for the non-defunct php processes as well. I am attaching a screen shot of the results strace -p pid command.
And, all these calls are to Magento's index.php page, which is usually the case with any CMS site.
We have done a fair bit of tweaking over the past week to fix front end issues through Y!Slow and Google Page Speed Insight, optimize Apache by moving to Worker MPM, optimize MySQL by running the mysqltuner.pl script every 24 hours etc., but nothing has an impact on these defunct and php processes and the high cpu loads they generate.
Does anyone have an idea how to identify these processes and stop them from generating such high cpu loads?
Thanks in advance.