Description of problem:

memcached starts, but cannot write its PID file and then is killed by systemd

Version-Release number of selected component (if applicable):

memcached-1.4.13-2.fc18

How reproducible:

100%

Steps to Reproduce:
1. systemctl enable memcached
2. systemctl start memcached
   (this takes a while, be patient)
3. verify failure
  
Actual results:

memcached is not available after reboot

Expected results:

memcached works

Additional info:

This happens because, on the one hand, the directory for PID files
is created one level down:

[root@kvm-rei zaitcev]# more /etc/tmpfiles.d/memcached.conf
D /var/run/memcached/memcached 0710 memcached memcached -
[root@kvm-rei zaitcev]# ls -la /var/run/memcached/
total 0
drwxr-xr-x.  3 root      root       60 Nov 19 14:06 .
drwxr-xr-x. 22 root      root      760 Nov 19 14:06 ..
drwx--x---.  2 memcached memcached  40 Nov 19 14:06 memcached
[root@kvm-rei zaitcev]# 

But on the other hand, the unit file specifies the PID file
in /var/run/memcached/, owned by root:

[root@kvm-rei zaitcev]# more /usr/lib/systemd/system/memcached.service
.................
[Service]
Type=forking
EnvironmentFile=-/etc/sysconfig/memcached
PIDFile=/var/run/memcached/memcached.pid
ExecStart=/usr/bin/memcached -d -u $USER -P /var/run/memcached/memcached.pid -p 
$PORT -m $CACHESIZE -c $MAXCONN $OPTIONS
.................
[root@kvm-rei zaitcev]# 

Once started by systemd, memcached cannot create PID file. Then,
systemd fails to find the PID file and terminates the control group.

The real root cause of the problem is using the "forking" type in the
unit file. The proper fix is to stop daemonizeing and use "simple" type.
In that case PID file is not necessary.