php7 occasionally slow problem

Question

Currently using PHP for interface development, I found that there are always less than 1% of requests, which is very slow.
Looking at the machine monitoring, I found that the memory and CPU have no jitter at all. Redis is used in the interface, and redis monitoring is also normal.
Has anyone encountered the same problem, or is there a way to monitor such problems and find out the cause?

Answer 1

1% of interface requests are slow. In addition to what you mentioned, there are many other possible reasons. For example, DNS resolution, network, etc.; it should not be the reason for PHP 7.