PID file is not created using systemd collectd service

[lukasmrtvy]

• Version of collectd: 5.6.0
• Operating system / distribution: Ubuntu 16.04

Expected behavior

Pid file is created using -P /tmp/collectd.pid as argument

Actual behavior

Run manually creates PID in /tmp
sudo /opt/collectd/sbin/collectd -P /tmp/collectd.pid

Run trough systemd does not create PID
/lib/systemd/system/collectd.service

[Unit]
Description=Statistics collection and monitoring daemon
After=local-fs.target network.target
Requires=local-fs.target network.target
ConditionPathExists=/etc/collectd/collectd.conf
Documentation=man:collectd(1)
Documentation=man:collectd.conf(5)
Documentation=https://collectd.org

[Service]
Type=notify
NotifyAccess=main
EnvironmentFile=-/etc/default/collectd
ExecStartPre=/opt/collectd/sbin/collectd -t
ExecStart=/opt/collectd/sbin/collectd -P /tmp/collectd.pid
Restart=always
RestartSec=10

[Install]
WantedBy=multi-user.target

[rubenk]

Why do you need a pid file when you're running under systemd?

[lukasmrtvy]

There are many other applications that use the pid file.
For example for monitoring.
I know I can grep process id and compare it with /proc/pid/status, but there is -P argument option, so why it does not use.

[rubenk]

This is by design. Collectd doesn't write the pid file if systemd monitors the process with Type=notify. If you need to get the process status you need to use the systemd tools (systemctl status) or apis. If you really want to keep using pid files and the associated racy behaviour, use Type=forking.

[bigHosting]

I know this is closed however I am running into issues because pid is not created. on CentOS 6 I use monit to monitor for pid files, but in CentOS 7 there is no pid file. My Ansible playbook looks at the distribution major release number and based on that, monitors the path to pid file. This works fine for auditd, chronyd, crond .... I am migrating to CentOS 7 however older CentOS 6 has to be still supported.

collectd:
pid:
6: '/var/run/collectdmon.pid'
7: '????'
start_script:
6: '/sbin/service collectd start'
7: '/usr/bin/systemctl collectd httpd.service'

stop_script:
6: '/sbin/service collectd stop'
7: '/usr/bin/systemctl stop collectd.service'

Thanks