I am aware that this is difficult to pinpoint from your side. I will try to investigate more and especially I think it would be good if you could help me to add some tracing (debug prints) in the code so that we could find the problem. I will try to answer yor questions below. A few questions: 1) Do you have similar issue without ssl support? I have not tried that. It is difficult to test since I am not aware how it is triggered and I do not want to expose my site without ssl. 2) Do you use SCOOP or Thread concurrency mode? Do you have same issue with any mode? I am using SCOOP 3) You said, it is about 10 times. Can you tell us the period? 10 times a day, a week, .. since your server is deployed? I takes several days at least until it fails after deploy. I am not sure what triggers it. If it is the execution time or the number of request or if it is some special combination of requests. 4) When this occurs, do you know if the server was running for a long time? or this does not matter? As I wrote above it takes at least several days until it happens. From the log, we have the pseudo id of the incoming request #.# , and it seems the first error appears quickly. 5) Do you know when the 100% CPU issue happened? To solve it, did you had to restart the server? I do not understand the first questions. What happens is that I detect that the web-server is not responding. Then I look at the server and see that it takes 100% of one of the CPUs. I then try to find out if I can contact the web-server in anyway, but without success. I then kill it with "kill -9 PID". I need to use "-9" since it otherwise does not stop. Then I restart the web-server and it works again. 6) Do you have by any luck, a system that I can run to reproduce the issue and debug it ? I will try to see if I can set up something, but I am not sure how to solve it. I assume I have to let you log in via ssh or something. How would you lie to do it?