mjhjmtu

I was trying to run flume on Ubuntu 16.04 as systemd service and have following in /etc/systemd/system/flume-ng.service

[Unit]
Description=Apache Flume

[Service]
ExecStart=/usr/bin/nohup /opt/flume/current/bin/flume-ng agent -c /etc/flume-ng/conf -f /etc/flume-ng/conf/flume.conf --name a1 &
ExecStop=/opt/flume/current/bin/flume-ng agent stop

[Install]
WantedBy=multi-user.target

I tried adding following lines

StandardOutput=/var/log/flume-ng/log1.log
StandardError=/var/log/flume-ng/log2.log 

which didn't work for me.
I did run systemctl daemon-reload and systemctl restart flume-ng

anyone know how this works ?

ExecStart=/usr/bin/nohup …

This is wrong. Remove it. This service is not running in an interactive login session. There is no controlling terminal, or session leader, to send a hangup signal to it in the first place.

ExecStart=… &

This is wrong. Remove it. This is not shell script. & has no special shell-like meaning, and in any case would be the wrong way to start a service.

StandardOutput=/var/log/flume-ng/log1.log
StandardError=/var/log/flume-ng/log2.log

These are wrong. Do not use these. systemd already sends the standard output and error of the service process(es) to its journal, without any such settings in the service unit. You can view it with

journalctl -e -u flume-ng.service

Use:

StandardOutput=file:/var/log/flume-ng/log1.log
StandardError=file:/var/log/flume-ng/log2.log

as documented here: https://www.freedesktop.org/software/systemd/man/systemd.exec.html#StandardOutput=

Note that this way log files contents will be overwritten each time service restarts. StandardOutput/Error systemd directives do not support appending to files.

If you want to maintain file log between service restarts and just append new logged lines to it, use instead:

ExecStart=/usr/bin/sh -c 'exec /usr/bin/my_binary [arguments] >>/var/log/flume-ng/log1.log 2>>/var/log/flume-ng/log2.log'

exec means that shell program will be substituted by my_binary program after setting up redirections without forking. So there will be no difference from running my_binary directly after ExecStart=.