Memory keeps increasing

Hi,

My nginx memory usage keeps increasing till it reaches max. I can't find the root cause since the configuration seems 'normal'

user nginx;
worker_processes 1;

error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;


events {
worker_connections 1024;
}


http {
include /etc/nginx/mime.types;
default_type application/octet-stream;

map_hash_bucket_size 128;
map $time_iso8601 $time_iso8601_p1 {
~(^[0-9]+-[0-9]+-[0-9]+) $1;
}
map $time_iso8601 $time_iso8601_p2 {
~T([0-9:]+) $1;
}
map $msec $millisec {
~\.([0-9]+)$ $1;
}
log_format main '[$time_iso8601_p1 $time_iso8601_p2,$millisec] - $remote_addr - $remote_user "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for"';

access_log /var/log/nginx/access.log main;

sendfile on;
#tcp_nopush on;

keepalive_timeout 65;
server_tokens off;

#gzip on;

include /etc/nginx/conf.d/*.conf;
}