You are viewing a plain text version of this content. The canonical link for it is here.
Posted to user@zookeeper.apache.org by adrien ruffie <ad...@hotmail.fr> on 2018/07/13 15:30:11 UTC
zookeeper as systemd
Hello Zookeeper's users,
I have 2 questions for you.
what is the real difference between these 2 following commands ? (I don't find any documentation)
zkServer.sh start-foreground
and
zkServer.sh start
My second question is, how I can correctly start my zookeeper as a systemclt service ?
What is the common best template to write into /etc/systemd/system/zookeeper.service ?
Do you use Restart=always ? RestartSec=0s ?
What is "After=network.target" ?
If my Zookeeper does not really start in 300 sec, the process will be shutdown ?
Do you have any example of zookeeper service file ?
Because our zookeeper.service is right now:
[Unit]
Description=ZooKeeper
[Service]
Type=simple
User=zookeeper
Group=zookeeper
ExecStart=/usr/local/zookeeper-3.4.9/bin/zkServer.sh start-foreground
TimeoutSec=300
[Install]
WantedBy=multi-user.target
------------------- But I found this following on a blog:
[Unit]
Description=Apache Zookeeper
After=network.target
[Service]
Type=forking
User=zookeeper
Group=zookeeper
SyslogIdentifier=zookeeper
Restart=always
RestartSec=0s
ExecStart=/usr/bin/zookeeper-server start
ExecStop=/usr/bin/zookeeper-server stop
ExecReload=/usr/bin/zookeeper-server restart
[Install]
WantedBy=multi-user.target
Thank you very much and best regards
Adrien
RE: zookeeper as systemd
Posted by adrien ruffie <ad...@hotmail.fr>.
thank you very much Norbert !
I take your useful suggestion, and try to launch zookeeper with your
service file.
Great thank,
Adrien
________________________________
De : Norbert Kalmar <nk...@cloudera.com.INVALID>
Envoyé : lundi 16 juillet 2018 16:18:36
À : user@zookeeper.apache.org
Objet : Re: zookeeper as systemd
Some prefer to use start-foreground to basically "bypass" the bash script
(and the background management), and make systemd care about it. Also to
ignore any nohup. So while it is also my understanding that the recommended
way is to start ZK with simple start, some use start-foreground to start as
a systemd service.
Type=simple - drawback is depending services (if any) will not know if it
is truly ready (sockets as well)
Type=forking - drawback is there might be some issues with the PID (file).
So you should also define where the pid file
is: PIDFILE="/var/run/zookeeper/zookeeper_server.pid"
Any combinations should work. It really comes down to preferans I think.
Disclaimer: I'm kind of trying to make educated guesses here, so a
Linux-slash-zookeeper guru could probably be more of a help here :)
This is how I would create systemd service file (this time using start not
start-foreground) - or something like that:
Put the systemd service file in: /etc/systemd/system/zookeeper.service
[Unit]
Description=Zookeeper
After=network.target syslog.target
[Service]
SyslogIdentifier=zookeeper
TimeoutStartSec=10min
Type=forking
User=zookeeper
Group=zookeeper
PIDFILE="/var/run/zookeeper/zookeeper_server.pid"
ExecStart=/usr/lib/zookeeper/bin/zkServer.sh start
ExecStop=/usr/lib/zookeeper/bin/zkServer.sh stop
WorkingDirectory=/var/lib/zookeeper
[Install]
WantedBy=multi-user.target
Of course not everything is required (User, Group, WorkingDirectory
possibly optional)
But I would dig deeper before saying anything for sure.
Regards,
Norbert
On Mon, Jul 16, 2018 at 3:01 PM adrien ruffie <ad...@hotmail.fr>
wrote:
> Thank Norbert for this good explanation.
>
> Yes I'm also a really lost here a bit ...
>
> But it's a zookeeper production's cluster of 5 nodes.
> It should be start instead start-foreground isn't it ? (with simple type)
> ________________________________
> De : Norbert Kalmar <nk...@cloudera.com.INVALID>
> Envoyé : lundi 16 juillet 2018 13:49:16
> À : user@zookeeper.apache.org
> Objet : Re: zookeeper as systemd
>
> The type is Linux config, and forking is used when we want the process to
> call fork() during startup. This should guarantee that when startup is
> finished, all ports are open. In my understanding, using FORKING will tell
> systemd the startup is complete and ports are open. See
> https://www.freedesktop.org/software/systemd/man/systemd.service.html for
> more information.
> TYPE=simple is mainly for daemons that don't use network channels, or they
> have their own socket activation.
>
> So in my opinion, TYPE=forking is better for ZK. But! Forking should
> require a PIDfile in order for it to work properly... but since systemd is
> used, it should know the PID as it is a supervisor. I'm also lost here a
> bit...
> Looking at ZK PID file should be
> available: ZOOPIDFILE="$ZOO_DATADIR/zookeeper_server.pid"
>
>
> About the simple start or start-foreground... I think I was quick to say
> only use simple start in prod environment. This is much more complicated,
> for example start-foreground would just make it ignore nohup.
>
> Doing some search, these 2 questions might help:
>
> https://stackoverflow.com/questions/40620544/systemd-zookeeper-service-failed
>
> https://askubuntu.com/questions/979498/how-to-start-a-zookeeper-daemon-after-booting-under-specific-user-in-ubuntu-serv
>
> Putting this all together, I think if you don't really care when socket is
> ready, just use TYPE=simple and call with start-foreground.
>
> Regards,
> Norbert
>
>
>
> On Mon, Jul 16, 2018 at 11:48 AM adrien ruffie <ad...@hotmail.fr>
> wrote:
>
> > Thank Nobert !
> >
> >
> > It really help me,
> >
> >
> > according to you, what would you recommend?
> >
> >
> > To launch with "Type=simple" and zkServer.sh start ?
> >
> > Or "Type=forking" and zkServer.sh start ?
> >
> >
> > Because start command launch Zookeeper as a Daemon,
> >
> > but if I use "Type=simple" the system already daemonize the process ...
> >
> > Do you think that can be daemonize a daemon ... ? Strange
> >
> >
> > I really ready to use "Type=forking" option but, according to this
> > following post
> >
> >
> > https://bbs.archlinux.org/viewtopic.php?id=191669
> >
> >
> > the "Type=forking" is not really recommended ...
> >
> > what do you think ?
> >
> >
> > Adrien
> >
> >
> > ________________________________
> > De : Norbert Kalmar <nk...@cloudera.com.INVALID>
> > Envoyé : lundi 16 juillet 2018 10:15
> > À : user@zookeeper.apache.org
> > Objet : Re: zookeeper as systemd
> >
> > Hi Adrien,
> >
> > zkServer.sh start-foreground - starts the ZooKeeper process in the
> > foreground. Good for debugging (thats what I use it for), or check
> > something, as you will have the logs printed to standard output (console
> > most probably).
> > The "start" is what you want to use in production environment. the
> process
> > will run in the background.
> >
> > ' What is "After=network.target" ? ' - ZooKeeper should only start
> after
> > the network... available? I think this should be something like
> > After=network-online.target
> >
> > But looking at the others, I'm not entirely sure either what they really
> > do. But checko out this jira -
> > https://issues.apache.org/jira/browse/ZOOKEEPER-2095
> >
> > There was a patch about this, and they added systemd startup/conf files.
> >
> > Sorry, this is all I could come up with, as I'm not familiar with this
> part
> > either. Hope it helps.
> >
> > Regards,
> > Norbert
> >
> >
> > On Fri, Jul 13, 2018 at 5:30 PM adrien ruffie <adriennolarsen@hotmail.fr
> >
> > wrote:
> >
> > > Hello Zookeeper's users,
> > >
> > >
> > > I have 2 questions for you.
> > >
> > >
> > > what is the real difference between these 2 following commands ? (I
> don't
> > > find any documentation)
> > >
> > >
> > > zkServer.sh start-foreground
> > >
> > > and
> > >
> > > zkServer.sh start
> > >
> > >
> > >
> > > My second question is, how I can correctly start my zookeeper as a
> > > systemclt service ?
> > >
> > > What is the common best template to write into
> > > /etc/systemd/system/zookeeper.service ?
> > >
> > > Do you use Restart=always ? RestartSec=0s ?
> > >
> > > What is "After=network.target" ?
> > >
> > > If my Zookeeper does not really start in 300 sec, the process will be
> > > shutdown ?
> > >
> > >
> > > Do you have any example of zookeeper service file ?
> > >
> > >
> > > Because our zookeeper.service is right now:
> > >
> > >
> > > [Unit]
> > > Description=ZooKeeper
> > >
> > > [Service]
> > > Type=simple
> > > User=zookeeper
> > > Group=zookeeper
> > > ExecStart=/usr/local/zookeeper-3.4.9/bin/zkServer.sh start-foreground
> > >
> > > TimeoutSec=300
> > >
> > > [Install]
> > > WantedBy=multi-user.target
> > >
> > > ------------------- But I found this following on a blog:
> > >
> > >
> > > [Unit]
> > > Description=Apache Zookeeper
> > > After=network.target
> > >
> > > [Service]
> > > Type=forking
> > > User=zookeeper
> > > Group=zookeeper
> > > SyslogIdentifier=zookeeper
> > > Restart=always
> > > RestartSec=0s
> > > ExecStart=/usr/bin/zookeeper-server start
> > > ExecStop=/usr/bin/zookeeper-server stop
> > > ExecReload=/usr/bin/zookeeper-server restart
> > >
> > > [Install]
> > > WantedBy=multi-user.target
> > >
> > >
> > > Thank you very much and best regards
> > >
> > > Adrien
> > >
> >
>
Re: zookeeper as systemd
Posted by Norbert Kalmar <nk...@cloudera.com.INVALID>.
Some prefer to use start-foreground to basically "bypass" the bash script
(and the background management), and make systemd care about it. Also to
ignore any nohup. So while it is also my understanding that the recommended
way is to start ZK with simple start, some use start-foreground to start as
a systemd service.
Type=simple - drawback is depending services (if any) will not know if it
is truly ready (sockets as well)
Type=forking - drawback is there might be some issues with the PID (file).
So you should also define where the pid file
is: PIDFILE="/var/run/zookeeper/zookeeper_server.pid"
Any combinations should work. It really comes down to preferans I think.
Disclaimer: I'm kind of trying to make educated guesses here, so a
Linux-slash-zookeeper guru could probably be more of a help here :)
This is how I would create systemd service file (this time using start not
start-foreground) - or something like that:
Put the systemd service file in: /etc/systemd/system/zookeeper.service
[Unit]
Description=Zookeeper
After=network.target syslog.target
[Service]
SyslogIdentifier=zookeeper
TimeoutStartSec=10min
Type=forking
User=zookeeper
Group=zookeeper
PIDFILE="/var/run/zookeeper/zookeeper_server.pid"
ExecStart=/usr/lib/zookeeper/bin/zkServer.sh start
ExecStop=/usr/lib/zookeeper/bin/zkServer.sh stop
WorkingDirectory=/var/lib/zookeeper
[Install]
WantedBy=multi-user.target
Of course not everything is required (User, Group, WorkingDirectory
possibly optional)
But I would dig deeper before saying anything for sure.
Regards,
Norbert
On Mon, Jul 16, 2018 at 3:01 PM adrien ruffie <ad...@hotmail.fr>
wrote:
> Thank Norbert for this good explanation.
>
> Yes I'm also a really lost here a bit ...
>
> But it's a zookeeper production's cluster of 5 nodes.
> It should be start instead start-foreground isn't it ? (with simple type)
> ________________________________
> De : Norbert Kalmar <nk...@cloudera.com.INVALID>
> Envoyé : lundi 16 juillet 2018 13:49:16
> À : user@zookeeper.apache.org
> Objet : Re: zookeeper as systemd
>
> The type is Linux config, and forking is used when we want the process to
> call fork() during startup. This should guarantee that when startup is
> finished, all ports are open. In my understanding, using FORKING will tell
> systemd the startup is complete and ports are open. See
> https://www.freedesktop.org/software/systemd/man/systemd.service.html for
> more information.
> TYPE=simple is mainly for daemons that don't use network channels, or they
> have their own socket activation.
>
> So in my opinion, TYPE=forking is better for ZK. But! Forking should
> require a PIDfile in order for it to work properly... but since systemd is
> used, it should know the PID as it is a supervisor. I'm also lost here a
> bit...
> Looking at ZK PID file should be
> available: ZOOPIDFILE="$ZOO_DATADIR/zookeeper_server.pid"
>
>
> About the simple start or start-foreground... I think I was quick to say
> only use simple start in prod environment. This is much more complicated,
> for example start-foreground would just make it ignore nohup.
>
> Doing some search, these 2 questions might help:
>
> https://stackoverflow.com/questions/40620544/systemd-zookeeper-service-failed
>
> https://askubuntu.com/questions/979498/how-to-start-a-zookeeper-daemon-after-booting-under-specific-user-in-ubuntu-serv
>
> Putting this all together, I think if you don't really care when socket is
> ready, just use TYPE=simple and call with start-foreground.
>
> Regards,
> Norbert
>
>
>
> On Mon, Jul 16, 2018 at 11:48 AM adrien ruffie <ad...@hotmail.fr>
> wrote:
>
> > Thank Nobert !
> >
> >
> > It really help me,
> >
> >
> > according to you, what would you recommend?
> >
> >
> > To launch with "Type=simple" and zkServer.sh start ?
> >
> > Or "Type=forking" and zkServer.sh start ?
> >
> >
> > Because start command launch Zookeeper as a Daemon,
> >
> > but if I use "Type=simple" the system already daemonize the process ...
> >
> > Do you think that can be daemonize a daemon ... ? Strange
> >
> >
> > I really ready to use "Type=forking" option but, according to this
> > following post
> >
> >
> > https://bbs.archlinux.org/viewtopic.php?id=191669
> >
> >
> > the "Type=forking" is not really recommended ...
> >
> > what do you think ?
> >
> >
> > Adrien
> >
> >
> > ________________________________
> > De : Norbert Kalmar <nk...@cloudera.com.INVALID>
> > Envoyé : lundi 16 juillet 2018 10:15
> > À : user@zookeeper.apache.org
> > Objet : Re: zookeeper as systemd
> >
> > Hi Adrien,
> >
> > zkServer.sh start-foreground - starts the ZooKeeper process in the
> > foreground. Good for debugging (thats what I use it for), or check
> > something, as you will have the logs printed to standard output (console
> > most probably).
> > The "start" is what you want to use in production environment. the
> process
> > will run in the background.
> >
> > ' What is "After=network.target" ? ' - ZooKeeper should only start
> after
> > the network... available? I think this should be something like
> > After=network-online.target
> >
> > But looking at the others, I'm not entirely sure either what they really
> > do. But checko out this jira -
> > https://issues.apache.org/jira/browse/ZOOKEEPER-2095
> >
> > There was a patch about this, and they added systemd startup/conf files.
> >
> > Sorry, this is all I could come up with, as I'm not familiar with this
> part
> > either. Hope it helps.
> >
> > Regards,
> > Norbert
> >
> >
> > On Fri, Jul 13, 2018 at 5:30 PM adrien ruffie <adriennolarsen@hotmail.fr
> >
> > wrote:
> >
> > > Hello Zookeeper's users,
> > >
> > >
> > > I have 2 questions for you.
> > >
> > >
> > > what is the real difference between these 2 following commands ? (I
> don't
> > > find any documentation)
> > >
> > >
> > > zkServer.sh start-foreground
> > >
> > > and
> > >
> > > zkServer.sh start
> > >
> > >
> > >
> > > My second question is, how I can correctly start my zookeeper as a
> > > systemclt service ?
> > >
> > > What is the common best template to write into
> > > /etc/systemd/system/zookeeper.service ?
> > >
> > > Do you use Restart=always ? RestartSec=0s ?
> > >
> > > What is "After=network.target" ?
> > >
> > > If my Zookeeper does not really start in 300 sec, the process will be
> > > shutdown ?
> > >
> > >
> > > Do you have any example of zookeeper service file ?
> > >
> > >
> > > Because our zookeeper.service is right now:
> > >
> > >
> > > [Unit]
> > > Description=ZooKeeper
> > >
> > > [Service]
> > > Type=simple
> > > User=zookeeper
> > > Group=zookeeper
> > > ExecStart=/usr/local/zookeeper-3.4.9/bin/zkServer.sh start-foreground
> > >
> > > TimeoutSec=300
> > >
> > > [Install]
> > > WantedBy=multi-user.target
> > >
> > > ------------------- But I found this following on a blog:
> > >
> > >
> > > [Unit]
> > > Description=Apache Zookeeper
> > > After=network.target
> > >
> > > [Service]
> > > Type=forking
> > > User=zookeeper
> > > Group=zookeeper
> > > SyslogIdentifier=zookeeper
> > > Restart=always
> > > RestartSec=0s
> > > ExecStart=/usr/bin/zookeeper-server start
> > > ExecStop=/usr/bin/zookeeper-server stop
> > > ExecReload=/usr/bin/zookeeper-server restart
> > >
> > > [Install]
> > > WantedBy=multi-user.target
> > >
> > >
> > > Thank you very much and best regards
> > >
> > > Adrien
> > >
> >
>
RE: zookeeper as systemd
Posted by adrien ruffie <ad...@hotmail.fr>.
Thank Norbert for this good explanation.
Yes I'm also a really lost here a bit ...
But it's a zookeeper production's cluster of 5 nodes.
It should be start instead start-foreground isn't it ? (with simple type)
________________________________
De : Norbert Kalmar <nk...@cloudera.com.INVALID>
Envoyé : lundi 16 juillet 2018 13:49:16
À : user@zookeeper.apache.org
Objet : Re: zookeeper as systemd
The type is Linux config, and forking is used when we want the process to
call fork() during startup. This should guarantee that when startup is
finished, all ports are open. In my understanding, using FORKING will tell
systemd the startup is complete and ports are open. See
https://www.freedesktop.org/software/systemd/man/systemd.service.html for
more information.
TYPE=simple is mainly for daemons that don't use network channels, or they
have their own socket activation.
So in my opinion, TYPE=forking is better for ZK. But! Forking should
require a PIDfile in order for it to work properly... but since systemd is
used, it should know the PID as it is a supervisor. I'm also lost here a
bit...
Looking at ZK PID file should be
available: ZOOPIDFILE="$ZOO_DATADIR/zookeeper_server.pid"
About the simple start or start-foreground... I think I was quick to say
only use simple start in prod environment. This is much more complicated,
for example start-foreground would just make it ignore nohup.
Doing some search, these 2 questions might help:
https://stackoverflow.com/questions/40620544/systemd-zookeeper-service-failed
https://askubuntu.com/questions/979498/how-to-start-a-zookeeper-daemon-after-booting-under-specific-user-in-ubuntu-serv
Putting this all together, I think if you don't really care when socket is
ready, just use TYPE=simple and call with start-foreground.
Regards,
Norbert
On Mon, Jul 16, 2018 at 11:48 AM adrien ruffie <ad...@hotmail.fr>
wrote:
> Thank Nobert !
>
>
> It really help me,
>
>
> according to you, what would you recommend?
>
>
> To launch with "Type=simple" and zkServer.sh start ?
>
> Or "Type=forking" and zkServer.sh start ?
>
>
> Because start command launch Zookeeper as a Daemon,
>
> but if I use "Type=simple" the system already daemonize the process ...
>
> Do you think that can be daemonize a daemon ... ? Strange
>
>
> I really ready to use "Type=forking" option but, according to this
> following post
>
>
> https://bbs.archlinux.org/viewtopic.php?id=191669
>
>
> the "Type=forking" is not really recommended ...
>
> what do you think ?
>
>
> Adrien
>
>
> ________________________________
> De : Norbert Kalmar <nk...@cloudera.com.INVALID>
> Envoyé : lundi 16 juillet 2018 10:15
> À : user@zookeeper.apache.org
> Objet : Re: zookeeper as systemd
>
> Hi Adrien,
>
> zkServer.sh start-foreground - starts the ZooKeeper process in the
> foreground. Good for debugging (thats what I use it for), or check
> something, as you will have the logs printed to standard output (console
> most probably).
> The "start" is what you want to use in production environment. the process
> will run in the background.
>
> ' What is "After=network.target" ? ' - ZooKeeper should only start after
> the network... available? I think this should be something like
> After=network-online.target
>
> But looking at the others, I'm not entirely sure either what they really
> do. But checko out this jira -
> https://issues.apache.org/jira/browse/ZOOKEEPER-2095
>
> There was a patch about this, and they added systemd startup/conf files.
>
> Sorry, this is all I could come up with, as I'm not familiar with this part
> either. Hope it helps.
>
> Regards,
> Norbert
>
>
> On Fri, Jul 13, 2018 at 5:30 PM adrien ruffie <ad...@hotmail.fr>
> wrote:
>
> > Hello Zookeeper's users,
> >
> >
> > I have 2 questions for you.
> >
> >
> > what is the real difference between these 2 following commands ? (I don't
> > find any documentation)
> >
> >
> > zkServer.sh start-foreground
> >
> > and
> >
> > zkServer.sh start
> >
> >
> >
> > My second question is, how I can correctly start my zookeeper as a
> > systemclt service ?
> >
> > What is the common best template to write into
> > /etc/systemd/system/zookeeper.service ?
> >
> > Do you use Restart=always ? RestartSec=0s ?
> >
> > What is "After=network.target" ?
> >
> > If my Zookeeper does not really start in 300 sec, the process will be
> > shutdown ?
> >
> >
> > Do you have any example of zookeeper service file ?
> >
> >
> > Because our zookeeper.service is right now:
> >
> >
> > [Unit]
> > Description=ZooKeeper
> >
> > [Service]
> > Type=simple
> > User=zookeeper
> > Group=zookeeper
> > ExecStart=/usr/local/zookeeper-3.4.9/bin/zkServer.sh start-foreground
> >
> > TimeoutSec=300
> >
> > [Install]
> > WantedBy=multi-user.target
> >
> > ------------------- But I found this following on a blog:
> >
> >
> > [Unit]
> > Description=Apache Zookeeper
> > After=network.target
> >
> > [Service]
> > Type=forking
> > User=zookeeper
> > Group=zookeeper
> > SyslogIdentifier=zookeeper
> > Restart=always
> > RestartSec=0s
> > ExecStart=/usr/bin/zookeeper-server start
> > ExecStop=/usr/bin/zookeeper-server stop
> > ExecReload=/usr/bin/zookeeper-server restart
> >
> > [Install]
> > WantedBy=multi-user.target
> >
> >
> > Thank you very much and best regards
> >
> > Adrien
> >
>
Re: zookeeper as systemd
Posted by Norbert Kalmar <nk...@cloudera.com.INVALID>.
The type is Linux config, and forking is used when we want the process to
call fork() during startup. This should guarantee that when startup is
finished, all ports are open. In my understanding, using FORKING will tell
systemd the startup is complete and ports are open. See
https://www.freedesktop.org/software/systemd/man/systemd.service.html for
more information.
TYPE=simple is mainly for daemons that don't use network channels, or they
have their own socket activation.
So in my opinion, TYPE=forking is better for ZK. But! Forking should
require a PIDfile in order for it to work properly... but since systemd is
used, it should know the PID as it is a supervisor. I'm also lost here a
bit...
Looking at ZK PID file should be
available: ZOOPIDFILE="$ZOO_DATADIR/zookeeper_server.pid"
About the simple start or start-foreground... I think I was quick to say
only use simple start in prod environment. This is much more complicated,
for example start-foreground would just make it ignore nohup.
Doing some search, these 2 questions might help:
https://stackoverflow.com/questions/40620544/systemd-zookeeper-service-failed
https://askubuntu.com/questions/979498/how-to-start-a-zookeeper-daemon-after-booting-under-specific-user-in-ubuntu-serv
Putting this all together, I think if you don't really care when socket is
ready, just use TYPE=simple and call with start-foreground.
Regards,
Norbert
On Mon, Jul 16, 2018 at 11:48 AM adrien ruffie <ad...@hotmail.fr>
wrote:
> Thank Nobert !
>
>
> It really help me,
>
>
> according to you, what would you recommend?
>
>
> To launch with "Type=simple" and zkServer.sh start ?
>
> Or "Type=forking" and zkServer.sh start ?
>
>
> Because start command launch Zookeeper as a Daemon,
>
> but if I use "Type=simple" the system already daemonize the process ...
>
> Do you think that can be daemonize a daemon ... ? Strange
>
>
> I really ready to use "Type=forking" option but, according to this
> following post
>
>
> https://bbs.archlinux.org/viewtopic.php?id=191669
>
>
> the "Type=forking" is not really recommended ...
>
> what do you think ?
>
>
> Adrien
>
>
> ________________________________
> De : Norbert Kalmar <nk...@cloudera.com.INVALID>
> Envoyé : lundi 16 juillet 2018 10:15
> À : user@zookeeper.apache.org
> Objet : Re: zookeeper as systemd
>
> Hi Adrien,
>
> zkServer.sh start-foreground - starts the ZooKeeper process in the
> foreground. Good for debugging (thats what I use it for), or check
> something, as you will have the logs printed to standard output (console
> most probably).
> The "start" is what you want to use in production environment. the process
> will run in the background.
>
> ' What is "After=network.target" ? ' - ZooKeeper should only start after
> the network... available? I think this should be something like
> After=network-online.target
>
> But looking at the others, I'm not entirely sure either what they really
> do. But checko out this jira -
> https://issues.apache.org/jira/browse/ZOOKEEPER-2095
>
> There was a patch about this, and they added systemd startup/conf files.
>
> Sorry, this is all I could come up with, as I'm not familiar with this part
> either. Hope it helps.
>
> Regards,
> Norbert
>
>
> On Fri, Jul 13, 2018 at 5:30 PM adrien ruffie <ad...@hotmail.fr>
> wrote:
>
> > Hello Zookeeper's users,
> >
> >
> > I have 2 questions for you.
> >
> >
> > what is the real difference between these 2 following commands ? (I don't
> > find any documentation)
> >
> >
> > zkServer.sh start-foreground
> >
> > and
> >
> > zkServer.sh start
> >
> >
> >
> > My second question is, how I can correctly start my zookeeper as a
> > systemclt service ?
> >
> > What is the common best template to write into
> > /etc/systemd/system/zookeeper.service ?
> >
> > Do you use Restart=always ? RestartSec=0s ?
> >
> > What is "After=network.target" ?
> >
> > If my Zookeeper does not really start in 300 sec, the process will be
> > shutdown ?
> >
> >
> > Do you have any example of zookeeper service file ?
> >
> >
> > Because our zookeeper.service is right now:
> >
> >
> > [Unit]
> > Description=ZooKeeper
> >
> > [Service]
> > Type=simple
> > User=zookeeper
> > Group=zookeeper
> > ExecStart=/usr/local/zookeeper-3.4.9/bin/zkServer.sh start-foreground
> >
> > TimeoutSec=300
> >
> > [Install]
> > WantedBy=multi-user.target
> >
> > ------------------- But I found this following on a blog:
> >
> >
> > [Unit]
> > Description=Apache Zookeeper
> > After=network.target
> >
> > [Service]
> > Type=forking
> > User=zookeeper
> > Group=zookeeper
> > SyslogIdentifier=zookeeper
> > Restart=always
> > RestartSec=0s
> > ExecStart=/usr/bin/zookeeper-server start
> > ExecStop=/usr/bin/zookeeper-server stop
> > ExecReload=/usr/bin/zookeeper-server restart
> >
> > [Install]
> > WantedBy=multi-user.target
> >
> >
> > Thank you very much and best regards
> >
> > Adrien
> >
>
RE: zookeeper as systemd
Posted by adrien ruffie <ad...@hotmail.fr>.
Thank Nobert !
It really help me,
according to you, what would you recommend?
To launch with "Type=simple" and zkServer.sh start ?
Or "Type=forking" and zkServer.sh start ?
Because start command launch Zookeeper as a Daemon,
but if I use "Type=simple" the system already daemonize the process ...
Do you think that can be daemonize a daemon ... ? Strange
I really ready to use "Type=forking" option but, according to this following post
https://bbs.archlinux.org/viewtopic.php?id=191669
the "Type=forking" is not really recommended ...
what do you think ?
Adrien
________________________________
De : Norbert Kalmar <nk...@cloudera.com.INVALID>
Envoyé : lundi 16 juillet 2018 10:15
À : user@zookeeper.apache.org
Objet : Re: zookeeper as systemd
Hi Adrien,
zkServer.sh start-foreground - starts the ZooKeeper process in the
foreground. Good for debugging (thats what I use it for), or check
something, as you will have the logs printed to standard output (console
most probably).
The "start" is what you want to use in production environment. the process
will run in the background.
' What is "After=network.target" ? ' - ZooKeeper should only start after
the network... available? I think this should be something like
After=network-online.target
But looking at the others, I'm not entirely sure either what they really
do. But checko out this jira -
https://issues.apache.org/jira/browse/ZOOKEEPER-2095
There was a patch about this, and they added systemd startup/conf files.
Sorry, this is all I could come up with, as I'm not familiar with this part
either. Hope it helps.
Regards,
Norbert
On Fri, Jul 13, 2018 at 5:30 PM adrien ruffie <ad...@hotmail.fr>
wrote:
> Hello Zookeeper's users,
>
>
> I have 2 questions for you.
>
>
> what is the real difference between these 2 following commands ? (I don't
> find any documentation)
>
>
> zkServer.sh start-foreground
>
> and
>
> zkServer.sh start
>
>
>
> My second question is, how I can correctly start my zookeeper as a
> systemclt service ?
>
> What is the common best template to write into
> /etc/systemd/system/zookeeper.service ?
>
> Do you use Restart=always ? RestartSec=0s ?
>
> What is "After=network.target" ?
>
> If my Zookeeper does not really start in 300 sec, the process will be
> shutdown ?
>
>
> Do you have any example of zookeeper service file ?
>
>
> Because our zookeeper.service is right now:
>
>
> [Unit]
> Description=ZooKeeper
>
> [Service]
> Type=simple
> User=zookeeper
> Group=zookeeper
> ExecStart=/usr/local/zookeeper-3.4.9/bin/zkServer.sh start-foreground
>
> TimeoutSec=300
>
> [Install]
> WantedBy=multi-user.target
>
> ------------------- But I found this following on a blog:
>
>
> [Unit]
> Description=Apache Zookeeper
> After=network.target
>
> [Service]
> Type=forking
> User=zookeeper
> Group=zookeeper
> SyslogIdentifier=zookeeper
> Restart=always
> RestartSec=0s
> ExecStart=/usr/bin/zookeeper-server start
> ExecStop=/usr/bin/zookeeper-server stop
> ExecReload=/usr/bin/zookeeper-server restart
>
> [Install]
> WantedBy=multi-user.target
>
>
> Thank you very much and best regards
>
> Adrien
>
Re: zookeeper as systemd
Posted by Norbert Kalmar <nk...@cloudera.com.INVALID>.
Hi Adrien,
zkServer.sh start-foreground - starts the ZooKeeper process in the
foreground. Good for debugging (thats what I use it for), or check
something, as you will have the logs printed to standard output (console
most probably).
The "start" is what you want to use in production environment. the process
will run in the background.
' What is "After=network.target" ? ' - ZooKeeper should only start after
the network... available? I think this should be something like
After=network-online.target
But looking at the others, I'm not entirely sure either what they really
do. But checko out this jira -
https://issues.apache.org/jira/browse/ZOOKEEPER-2095
There was a patch about this, and they added systemd startup/conf files.
Sorry, this is all I could come up with, as I'm not familiar with this part
either. Hope it helps.
Regards,
Norbert
On Fri, Jul 13, 2018 at 5:30 PM adrien ruffie <ad...@hotmail.fr>
wrote:
> Hello Zookeeper's users,
>
>
> I have 2 questions for you.
>
>
> what is the real difference between these 2 following commands ? (I don't
> find any documentation)
>
>
> zkServer.sh start-foreground
>
> and
>
> zkServer.sh start
>
>
>
> My second question is, how I can correctly start my zookeeper as a
> systemclt service ?
>
> What is the common best template to write into
> /etc/systemd/system/zookeeper.service ?
>
> Do you use Restart=always ? RestartSec=0s ?
>
> What is "After=network.target" ?
>
> If my Zookeeper does not really start in 300 sec, the process will be
> shutdown ?
>
>
> Do you have any example of zookeeper service file ?
>
>
> Because our zookeeper.service is right now:
>
>
> [Unit]
> Description=ZooKeeper
>
> [Service]
> Type=simple
> User=zookeeper
> Group=zookeeper
> ExecStart=/usr/local/zookeeper-3.4.9/bin/zkServer.sh start-foreground
>
> TimeoutSec=300
>
> [Install]
> WantedBy=multi-user.target
>
> ------------------- But I found this following on a blog:
>
>
> [Unit]
> Description=Apache Zookeeper
> After=network.target
>
> [Service]
> Type=forking
> User=zookeeper
> Group=zookeeper
> SyslogIdentifier=zookeeper
> Restart=always
> RestartSec=0s
> ExecStart=/usr/bin/zookeeper-server start
> ExecStop=/usr/bin/zookeeper-server stop
> ExecReload=/usr/bin/zookeeper-server restart
>
> [Install]
> WantedBy=multi-user.target
>
>
> Thank you very much and best regards
>
> Adrien
>