uwsgi会产生很多奇怪的过程，就像已经消失的过程一样

Question

I have a web project,use nginx ,uwsgi ,web.py ,nginx is used for load balancing,uwsgi is used as a web server,web.py is a web frameworks

I start it with this commond "/usr/local/bin/uwsgi -d /home/sheng/www/lr-server/../log/lr-server/uwsgi.log -s 127.0.0.1:8666 -w rc_main -t 20 -M -p 20 --pidfile /home/sheng/www/lr-server/master.pid --enable-threads -R 800"

this commond means it will produce twenty process to receive request, and each process receive 800 requests as most

as show below is normal process

sheng     12414 15051 21 10:04 ?        00:01:45 /usr/local/bin/uwsgi -d /home/sheng/www/lr-server/../log/lr-server/uwsgi.log -s 127.0.0.1:8666 -w rc_main -t 20 -M -p 20 --pidfile /home/sheng/www/lr-server/master.pid --enable-threads -R 800

15051 is parent pid

usually it works normal ,but it will produce strange process when server is very busy and many requests take a long time, as shown below is strange process:

sheng     23370     1  0 09:08 ?        00:00:00 /usr/local/bin/uwsgi -d /home/sheng/www/lr-server/../log/lr-server/uwsgi.log -s 127.0.0.1:8666 -w rc_main -t 20 -M -p 20 --pidfile /home/sheng/www/lr-server/master.pid --enable-threads -R 800

you will notice,this process's pid is 23370,but it's parent pid is 1,it like a defunct process.However, in fact，this process take up memory and will not receive any request

I had hoped to produce 20 normal process to receive request,but now ,it process more then 80 starnge process,who can tell me why and what can I do to solve this problem

Answer 1

I have found out the reason

In my python project , sometimes python will use R to make a scientific calculation

R is slow ,so a colleague of mine use parallel technology,R will fork some child process to calculate

Unfortunately，if a request take more than 20 seconds ,uwsgi will kill the python process,but due to unknown reasons, those child process which R forked will not be killed ,they are just strange process what I see