Zookeeper service?

[Scott Prentice <sp...@leximation.com>]

We might be going at this wrong, but we've got Solr set up as a service, 
so if the machine goes down it'll restart. But without Zookeeper running 
as a service, that's not much help. I found the zookeeperd install, 
which in theory seems like it should do the trick, but that installs a 
new instance of ZK and isn't using our zoo.cfg. I guess we can make the 
config adjustments to the new ZK installation and use that, but was 
hoping to use our existing ZK installation. Or maybe I can hack the 
zookeeper startup script to get it to run as a service?

There's the SOLR_WAIT_FOR_ZK config parameter, so Solr will wait for ZK 
to fire up .. seems like it's partially there.

This all seems like too many hoops to jump through to be the "right" way 
to go. I assume that others have run into a similar situation?

Thoughts?

Thanks!
...scott

Re: Zookeeper service?

[Scott Prentice <sp...@leximation.com>]

Yeah .. I knew it was a different Apache project, but figured that since 
it was so tightly integrated with SolrCloud that others may have run 
into this issue.

I did some poking around and have (for now) ended up with this .. 
implemented it as a service through the "systemd.unit" configuration. 
Created the following unit file here .. 
/etc/systemd/system/zookeeper.service

-----
[Unit]
Description=Zookeeper Daemon
Wants=syslog.target

[Service]
Type=forking
ExecStart=/apps/local_data/apps/solr/zk_installation/zookeeper/bin/zkServer.sh 
start /apps/local_data/apps/solr/zk_distribution/zoo.cfg
ExecStop=/apps/local_data/apps/solr/zk_installation/zookeeper/bin/zkServer.sh 
stop /apps/local_data/apps/solr/zk_distribution/zoo.cfg
TimeoutSec=30
Restart=on-failure

[Install]
WantedBy=multi-user.target
-----

Rebooted the server and it seems to work. Your implementation sounds 
reasonable as well. I may post a query to the ZK list to see what other 
options are out there. The zookeeperd install seemed like it was going 
to require more hacking than I wanted to do since our config was already 
set up and working.

Thanks Shawn!

...scott



On 3/14/18 5:17 PM, Shawn Heisey wrote:
> On 3/14/2018 12:24 PM, Scott Prentice wrote:
>> We might be going at this wrong, but we've got Solr set up as a
>> service, so if the machine goes down it'll restart. But without
>> Zookeeper running as a service, that's not much help.
> You're probably going to be very unhappy to be told this ... but
> ZooKeeper is a completely separate Apache project.  This mailing list
> handles Solr.  While SolrCloud does require ZK, setting it up is outside
> the scope of this mailing list.
>
> I can tell you what I did to get it running as a service on CentOS 6.
> It works, but it's not very robust, and if you ask the zookeeper user
> mailing list, they may have better options.  I do strongly recommend
> that you ask that mailing list.
>
> ---------------------
>
> I extracted the .tar.gz file to the "/opt" folder.  Then I renamed the
> zookeeper-X.Y.Z directory to something else.  I used "mbzoo" ... which
> only makes sense if you're familiar with our locally developed software.
>
> Next I created a very small shell script, and saved it as
> /usr/local/sbin/zkrun (script is below between the lines of equal signs):
>
> =====
> #!/bin/sh
>
> # chkconfig: - 75 50
> # description: Starts and stops ZK
>
> cd /opt/mbzoo
> bin/zkServer.sh $1
> =====
>
> I made that script executable and created a symlink for init.d:
>
> chown +x /usr/local/sbin/zkrun
> ln -s /usr/local/sbin/zkrun /etc/init.d/zookeeper
>
> Then all I had to do was activate the init script:
>
> chkconfig --add zookeeper
> chkconfig zookeeper on
>
> Once that's done, a "service zookeeper start" command should work.
>
> On debian/ubuntu/mint and similar distros, you'd probably use
> update-rc.d instead of chkconfig, with different options.  If you're on
> an OS other than Linux, everything I've described might need changes.
>
> If you're on Windows, chances are that you'll end up using a program
> named NSSM.  If you can get your company to accept using it once they
> find out the FULL program name.
>
> Thanks,
> Shawn
>
>

Re: Zookeeper service?

[Shawn Heisey <ap...@elyograg.org>]

On 3/14/2018 12:24 PM, Scott Prentice wrote:
> We might be going at this wrong, but we've got Solr set up as a
> service, so if the machine goes down it'll restart. But without
> Zookeeper running as a service, that's not much help.

You're probably going to be very unhappy to be told this ... but
ZooKeeper is a completely separate Apache project.  This mailing list
handles Solr.  While SolrCloud does require ZK, setting it up is outside
the scope of this mailing list.

I can tell you what I did to get it running as a service on CentOS 6. 
It works, but it's not very robust, and if you ask the zookeeper user
mailing list, they may have better options.  I do strongly recommend
that you ask that mailing list.

---------------------

I extracted the .tar.gz file to the "/opt" folder.  Then I renamed the
zookeeper-X.Y.Z directory to something else.  I used "mbzoo" ... which
only makes sense if you're familiar with our locally developed software.

Next I created a very small shell script, and saved it as
/usr/local/sbin/zkrun (script is below between the lines of equal signs):

=====
#!/bin/sh

# chkconfig: - 75 50
# description: Starts and stops ZK

cd /opt/mbzoo
bin/zkServer.sh $1
=====

I made that script executable and created a symlink for init.d:

chown +x /usr/local/sbin/zkrun
ln -s /usr/local/sbin/zkrun /etc/init.d/zookeeper

Then all I had to do was activate the init script:

chkconfig --add zookeeper
chkconfig zookeeper on

Once that's done, a "service zookeeper start" command should work.

On debian/ubuntu/mint and similar distros, you'd probably use
update-rc.d instead of chkconfig, with different options.  If you're on
an OS other than Linux, everything I've described might need changes.

If you're on Windows, chances are that you'll end up using a program
named NSSM.  If you can get your company to accept using it once they
find out the FULL program name.

Thanks,
Shawn